Problem Solving Deteriorates Following Mood Challenge in Formerly
Depressed Patients With a History of Suicidal Ideation
J. Mark G. Williams, Thorsten Barnhofer, and A. T. Beck
Catherine Crane University of Pennsylvania University of Oxford
The authors divided 34 participants who had a history of depression into 2 groups, those having previous
suicidal ideation or behavior (n � 19) and those having no such symptoms (n � 15), then compared the
2 groups with a group of participants who had no history of depression (n � 22). Assessment of
interpersonal problem-solving performance using the Means-Ends Problem-Solving (MEPS) task before
and after a mood-induction procedure showed that only those formerly depressed people with a history
of suicidal ideation shifted in MEPS performance, producing significantly less effective problem
solutions following mood challenge, consistent with a differential activation account of vulnerability for
recurrence of suicidal ideation and behavior. The deterioration in effectiveness following mood
challenge was moderated by lack of specificity in autobiographical memory.
Keywords: depression, suicide, differential activation, problem solving, autobiographical memory
We are interested in the factors that determine vulnerability to
suicide and suicidal behavior. Suicidal behavior occurs most frequently in the context of an episode of psychiatric disorder, most
commonly depression (Molnar, Berkman, & Buka, 2001), and the
population attributable ratio (PAR) for depression in serious but
nonfatal suicidal behavior (that proportion of suicidal behavior
that would be removed if depression were removed) is 80%
(Beautrais et al., 1996). However, because the vast majority of
depressed patients do not attempt or commit suicide, research has
focused on finding the additional risk factors that predict suicidal
ideation and behavior.
In our previous work, we have suggested that a major determinant
of whether depressed mood escalates into suicidal thoughts and
behavior is the unavailability of alternative coping options. This
lack of options can mean that a person, when a situation becomes
stressful, may feel trapped (the “arrested flight” model, Williams
& Pollock, 2000). Many studies suggest that deficits in
interpersonal problem solving in suicidal patients may be a critical
factor in reducing coping options. These deficits then feed back in
a vicious circle to reinforce suicide ideation. In one half of the
vicious circle, problem-solving deficits increase helplessness,
hopelessness, and feelings of being trapped, all of which intensifies suicidal ideation. In the next half of the circle, ideation—itself
one of the most severe forms of self-focused rumination—further
impairs problem solving (Watkins & Baracaia, 2002).
J. Mark G. Williams, Thorsten Barnhofer, and Catherine Crane, Department of Psychiatry, University of Oxford, Oxford, United Kingdom; A. T.
Beck, Psychopathology Research Unit, Department of Psychiatry, University of Pennsylvania.
This research was supported by Wellcome Trust Grant GR067797. We
thank Danielle Duggan, Melanie Fennell, Silvia Garnsey, and Wendy
Swift for help with and discussion of this article.
Correspondence concerning this article should be addressed to J. Mark
G. Williams, University Department of Psychiatry, Warneford Hospital,
Oxford OX3 7JX, United Kingdom. E-mail: mark.williams@psych.ox
.ac.uk
Typically, studies have used the Means-Ends Problem-Solving
(MEPS) procedure (Platt, Spivack, & Bloom, 1975) because deficits on this measure are closely associated with a patient’s difficulty in finding ways to solve real-life problems (Marx, Williams,
& Claridge, 1992; Rotheram-Borus, Trautman, Dopkins, &
Shrout, 1990). Research has consistently found that suicidal patients are poor at generating relevant and effective means to deal
with their interpersonal problems (in fact, they may be poorer
problem solvers in general, though most research has focused on
the interpersonal domain; Pollock & Williams, 1998). Differences
in problem-solving ability between these groups are not attributable to differences in general intelligence (Biggam & Power,
1999). Importantly, problem-solving deficits are more severe in
suicidal patients even if these patients are compared with other
psychiatric patients matched for severity of illness and with depressed mood covaried out (Pollock & Williams, 2001). It appears
that poor problem solving, a general feature of people who suffer
psychiatric disturbance, is particularly associated with suicidality.
However, there is a problem in interpreting these results: Problem
solving has usually been measured soon after the suicidal episode.
It is therefore not possible to determine to what extent these
deficits are long-term traits that render patients vulnerable or how
much they are state-dependent—that is, simply a feature of
short-term suicidal crises. The data on this point remain ambiguous. Despite early studies showing that MEPS performance was a
trait feature, or diathesis (Schotte & Clum, 1987), there is also
evidence that problem solving is state-dependent: Performance
that is poor in a crisis rapidly recovers (Biggam & Power, 1999;
Schotte, Cools, & Payvar, 1990) and the relationship between
problem solving and repetition of suicidal behavior weakens when
current level of depression is partialed out (Hawton, Kingsbury,
Steinhardt, James, & Fagg, 1999). The conclusion from available
studies is that a “simple, diathesis stress model appears to be
inadequate
in
explaining
the
relationship
between
problem-solving skills and suicidal behavior . . . the direction of
the relationship has not yet been adequately resolved” (Biggam &
Power, 1999, p. 38).
421
This theoretical issue has important clinical implications. If, once
the suicidal crisis is past, problem solving returns to normal, then
it is difficult to know which patient remains vulnerable, or
whether any therapy is succeeding in dealing with the underlying
vulnerability. How can we determine which individuals remain
vulnerable to future suicidal crises even when they appear to have
completely recovered?
Recently we have suggested that this question may best be
answered in the context of differential activation theory (Lau,
Segal, & Williams, 2004), which was developed to explain why
people remain vulnerable to depressive recurrence even when the
usual cognitive vulnerability markers (e.g., dysfunctional
attitudes) appear to have normalized on recovery. The theory
states that it is not the “resting level” of such attitudes when
euthymic that determines vulnerability, but how easily these
attitudes are reactivated by small changes in mood.
Why might suicidality be particularly explicable by differential
activation theory, which has heretofore been applied only to depression in general? The original theory stated that during a
person’s learning history—and particularly during episodes of
depression—low mood becomes associated with patterns of negative information processing (biases in memory, interpretations,
and attitudes). Any return of the mood reactivates the pattern, and
if the content of what is reactivated is global, negative, and
self-referent (e.g., “I am a failure; worthless and unlovable”), then
relapse and recurrence of depression is highly likely (Teasdale,
1988). Of all the noncore symptoms of depression, suicidal ideation (as well as guilt, with which it is closely associated) is the
one that represents the most severe type of negative global
self-referent thinking pattern. Although other symptoms of
depression (e.g., appetite and sleep changes, fatigue, agitation or
retardation, and concentration difficulties) are important features
of the depressive picture, they are not themselves patterns of
self-referent thoughts. Thus we might expect that suicidal
ideation, once initiated, may become linked with other negative
global self-referent thought (Malone et al., 2000). Vulnerability to
recurrence of suicidal ideation and behavior consists of the ease
with which these specific cognitive patterns can be reactivated by
small amounts of negative mood.
How can we test whether differential activation theory applies to
suicidality? The usual procedure to test the theory as it applies to
depression is to use mood challenge (Ingram, Miranda, & Segal,
1998; Segal & Ingram, 1994). In these experiments, people who
have recovered from depression are compared with people who
have never been depressed. Dysfunctional attitudes, memory bias,
attentional bias, or self-referent descriptions are measured before
and after the mood challenge. There have been some discrepant
results, but the majority of studies report that those who have been
depressed in the past, although not distinguishable before the
mood challenge, show a reactivated pattern of negative cognitions
following the mood challenge (Lau et al., 2004).
In order to investigate whether this model is applicable to suicidal
vulnerability, we needed to show that patients assessed during
recovery would show no evidence of suicidal vulnerability but
that, following a mood challenge, the vulnerability would become
clear. Furthermore, because our previous research had shown that
problem-solving deficits are a signature characteristic of
suicidality, we hypothesized that mood challenge would differentially affect problem-solving ability in those patients who had
been suicidal in the past.
To test this hypothesis, we followed previous studies by recruiting
a sample of people who had an episode of major depression in the
past and a comparison sample of people who had never been
depressed, then asking both groups to undergo a mood challenge.
However, we added two features that were different from previous
studies. First, using both clinical interviews and questionnaires,
we divided the previously depressed group into those who either
had or had not experienced suicidal ideation and behavior when
depressed. Second, rather than using a test of dysfunctional
attitudes as our outcome variable (as in most previous studies of
differential activation), we had participants complete the MEPS
test before and after the mood challenge. We report data showing
that, whereas all participants showed significantly greater mood
disturbance as a result of the mood challenge, only those
participants with suicidality in their past were affected in their
problem-solving performances (i.e., they generated solutions that
were significantly less effective).
This study also gave us the opportunity to examine the relation
between differential activation processes and autobiographical
memory. Research has found that depressed and suicidal patients
tend to respond to cue words in an Autobiographical Memory Test
with memories that are less specific; that is, their responses do not
single out a particular event (e.g., happy 7 “going for a long walk
three weeks ago”) but instead are overgeneral (e.g., happy 7
“going for long walks”) (Pollock & Williams, 2001; Williams,
2004; Williams & Broadbent, 1986; Williams et al., 1996). Moreover, research shows that patients’ difficulties in being specific
about the past are associated with difficulties in problem solving:
Failure to retrieve specific memories prevents patients from accessing previous occasions when they have solved analogous
problems in the past (Evans, Williams, O’Loughlin, & Howells,
1992; Pollock & Williams, 2001).
How might overgeneral memory interact, then, with differential
activation theory? If reactivation of suicidal cognition affects
problem solving as we predict, then those people who have
difficulty in retrieving specific memories will be more vulnerable
to the effects of mood challenge. They will have fewer adequate
representations of past coping behavior to help generate
alternative solutions to current problems as their problem-solving
process comes under stress from mood disturbance.
We therefore administered a test of autobiographical memory
before and after the mood induction. It was not clear whether
specificity would change with mood, inasmuch as the evidence is
ambiguous with respect to this question (MacCallum, McConkey,
Bryant, & Barnier, 2000; McBride & Cappeliez, 2004; Svaldi &
Mackinger, 2003). We found no effect of mood on overgenerality
in memory, so memory could not be a mediator of change in
problem-solving performance. Nevertheless, we report data showing that level of memory specificity prior to the mood challenge
moderated the extent to which problem solving deteriorated.
Method
Participants
We recruited participants by contacting people who had taken part in
previous studies in the University of Oxford’s Department of Psychiatry
and by advertising on the website of a local newspaper. Participants from
previous studies had indicated their willingness to be contacted again for
further research and, as part of the previous studies, had completed questionnaires about prior history of depression. This factor allowed us to
conduct purposive sampling, contacting an equal number of those who had
indicated a history of major depression, with or without suicidal ideation,
and a similar number of those who had indicated that they had never been
depressed.
We contacted 185 (108 female, 77 male, age: M �47.03, SD �7.97)
potential participants in the Oxford region by letter; 57 (35 female, 22
male, age: M �47.82, SD �7.6) responded. Age and sex distribution did
not differ between those who volunteered and those who did not: sex,
� (1, N �145) �.07, ns; age, t(143) ��.62, ns. Another 14 participants
(10 female, 4 male; 10 formerly depressed, 4 never depressed; age M
�31.2, SD �11.1) were recruited via the advertisements on the local
newspaper website. This group did not differ in sex distribution, � (71)
�.48, p �.10, but was significantly younger than those participants who
had taken part in previous research, t(69) �6.7, p �.01.
Current and past diagnostic status was assessed using the Structured
Clinical Interview for DSM–IV Axis I (SCID-I; First, Spitzer, Gibbon, &
Williams, 1996) with the addition of the Borderline Personality Disorder
section from the SCID-II (First, Gibbon, Spitzer, & Williams, 1997). All
interviews were administered by a postdoctoral clinical or research psychologist. To be included in the study, participants had to meet the
National Institute of Mental Health criterion for remission of depression:
being symptom-free for at least 8 weeks (Frank et al., 1991; Keller,
Shapiro, Lavori, & Wolfe, 1982). In addition, participants had to be from
18 to 65 years of age. Five participants were excluded because they failed
to meet criteria for recovery and 7 more participants were excluded
because of current active or passive suicidal ideation (assessed during the
clinical interview and on the basis of responses to the Beck Scale for
Suicide Ideation [BSS], as described in the Measures section). Also, 1
participant was excluded because of current mania, 1 because of current
psychotic
symptoms,
and 1 of
because
of age exceeding
upper limit.on the
We
defined
three groups
participants
according the
to responses
SCIDs and the BSS—“Worst Ever” (BSSW) questionnaire described in the
Measures section. The first group (Control; n �22) comprised individuals
with no history of major depressive disorder (MDD) or suicidality. The
second group (MDD-suic; n �19) comprised individuals with a history of
MDD who also had reported past suicidal ideation either during the
clinical interview or on the BSSW questionnaire. The third group (MDD-no
suic; n �15) comprised individuals with a history of MDD who did not
report past suicidal ideation during the interview or on the BSSW. Table 1
shows the median ages and the sex distributions of the groups; there was
no
significant
difference
groups
terms
of thesedepressed
demographics.
Analysis
was carried
outbetween
to compare
the in
two
previously
groups
2
2
in terms of the presence of other core symptoms of MDD, in order to
ensure that the groups were matched in this regard. Only symptoms rated
Table 1
Demographics and Symptom Scores for Control Group and
Previously Depressed Participants
MDD-no suicb
Controla
Variable
Demographic
Age Symptom
score BDI
BHS BSSw
MDD-suicc
M
SD
M
SD
M
SD
49.6
4.1 2.8
0.0
7.3
4.2
2.7
0.0
43.6
8.4
4.7
0.6
9.2
4.7
4.2
1.1
42.9
12.0
7.0
13.3
12.
0
8.0
3.8
7.4
Note. BDI �Beck Depression Inventory; BHS �Beck Hopelessness
Scale; BSSw �Beck Scale for Suicide Ideation—Worst ever. MDD �
major depressive disorder; suic �suicidality history. Control group, n
�22 (13 female, 9 male). Participants with history of MDD but no suic, n
�15 (9 female, 6 male). Participants with both history of MDD and suic,
n �19 (14 female, 5 male).
a
b
c
as definitely present during the participants’ worst episode of MDD, as
assessed by the SCID interviews, were analyzed. Fisher’s exact test (twotailed) was used to examine possible differences between the MDD-suic
and MDD-no suic groups. Table 2 shows the percentages of participants in
the MDD-suic and MDD-no suic groups reporting each core symptom of
MDD. No significant differences between the groups were identified
regarding the presence of any of the core symptoms of MDD.
Table 2 also shows that the two groups did not differ significantly
regarding either the number of prior episodes of MDD reported or the age
at first onset of MDD/dysthymia. Differences in mean length of the
longest past episode also were not significant, although episodes were
numerically longer in those with previous suicidal ideation than in those
without such ideation, F(1, 32) �2.06, p �.16. Past episodes with a
duration of 2 years or longer were reported by 6 of the participants in the
group with previous suicidal ideation and 1 participant in the group
without suicidal ideation, Fisher’s exact test (one-sided) p � .09. Criteria
for a past history of dysthymic disorder were met by 1 participant in the
group with previous suicidal ideation and 2 participants in the group
without suicidal ideation. A past episode of mania was diagnosed in 1
participant in the previously depressed group without suicidal ideation and
1 participant in the previously depressed group with suicidal ideation.
Additionally, 1 of the participants in the previously suicidal group
reported
having suffered
a single
(antidepressant-induced)
episode
of
SCID
interviews
revealedfrom
current
diagnoses
for psychiatric disorders
other
hypomania
at theinage
than
depression
18 of 16.
the participants. Criteria for either a full diagnosis
or partial remission were met in 3 of the 22 control participants (2 specific
phobia, 1 social phobia); 7 of the 15 participants in the MDD-no suic
group (2 generalized anxiety disorder [1 in partial remission], 1 social
phobia and obsessive–compulsive disorder, 1 specific phobia and
obsessive–compulsive disorder, 1 alcohol dependence in early full remission, 1 alcohol dependence in full remission with current mild problems,
and 1 panic disorder in partial remission); and 8 of the 19 participants in
the MDD-suic group (4 specific phobia, 1 bulimia nervosa in partial
remission, 1 panic disorder in partial remission, 1 panic disorder with
agoraphobia, and 1 borderline personality disorder and alcohol
dependence in early full remission). Severity ratings of the disorder did
not exceed a mild-tomoderate degree in any of the cases.
Measures
Visual Analog Scale (VAS) mood rating. Two VASs, each 10 cm in length,
were used to rate the participant’s mood (from despondency to happiness)
on four occasions during the testing session: once immediately prior to
commencing the experimental tasks, once immediately prior to the mood
induction, once immediately following the mood induction, and once at
the end of the experimental tasks. For each rating the statement “At this
moment I feel . . . ” was printed above the line and either “happy” or
“despondent” was printed below the line, anchored on a scale of not at all
Beck Depression Inventory (BDI-II). The BDI-II is a well-established
to extremely.
measure of depressive symptomatology that contains 21 groups of statements, referring to the presence of symptoms of depression over the
preceding 2 weeks (Beck, Steer, & Brown, 1996).
BSS. The BSS scale contains 21 groups of statements referring to the
presence or absence of various forms of suicidal ideation (thoughts, plans,
or wishes to commit suicide) during the preceding week (Beck & Steer,
1993b; Beck, Steer, & Ranieri, 1988).
BSSW. This questionnaire, a modified version of the BSS developed for
this study, is based on the clinician-rated Scale for Suicidal Ideation
worst-point suicidality interview, which has been used in several studies
(e.g., Joiner et al., 2003). Research suggests that worst-point suicidality
represents a significant predictor of an individual’s future risk of death by
suicide (Beck, Brown, Steer, Dahlsgaard, & Grisham, 1999). The BSSW
questionnaire contains the same items as the BSS but is worded in the past
tense, requiring respondents to indicate at what time in their life they felt
the “most down about life, the most depressed you have been,” and then
report on their suicidal ideation at that time.
Table 2
Worst-Episode Symptoms, Treatment Experience, and Symptom History of Previously Depressed
Participants
MDD-no suic MDD-suic Variable n %of Nn %of N Fisher’s exact test p
Worst-episode symptoms (assessed) Loss of interest 15 100 17 89 .49 Appetite or weight change 11
73 14 74 1.00 Sleep disturbance 10 73 17 89 .19 Agitation/retardation 10 67 13 68 1.00 Fatigue 13 87
15 79 .67 Worthlessness/guilt 14 93 15 79 .35 Indecisiveness/concentration 15 100 17 89 .49
Treatment experience Antidepressants (last episode) 6 40 12 63 .16 Counseling/psychotherapy (ever)
6 40 11 58 .46 Antidepressants (current) 3 20 2 11 .63
M SD M SD Analysis of variance p
Symptom history Age at onset 25.2 9.6 21.5 11.0 .32 No. of prior episodes 2.5 1.9 3.0 2.4 .51 Longest
episode (months) 7.8 12.09 15.1 16.47 .16
a
Note. MDD � major depressive disorder; suic � suicidality history; SCID � Structured Clinical Interview for
DSM–IV. Age at onset refers to onset of any depressive disorder (i.e., includes dysthymia for 2 participants in
MDD-no suic group and 1 in MDD-suic group).
a
Beck Hopelessness Scale (BHS). The BHS contains 20 statements
describing negative and positive attitudes toward the future (Beck & Steer,
1993a).
MEPS task. Participants were presented with problem scenarios on cards
that were simultaneously read aloud by the experimenter. Each scenario
outlined an initial situation in which there was a problem to be solved and
a desired end point (Marx, Williams, & Claridge, 1992; Platt et al., 1975).
In line with previous studies in suicidal and depressed populations, rather
than presenting the MEPS as a test of imagination, a clear problem-solving
set was introduced, with participants given 60 s to describe the most
effective strategy for solving the problem (Marx, Williams & Claridge,
1992; Watkins & Baracaia, 2002). In the current study, participants were
given an additional 60 s to describe alternative strategies for solving the
problem. For each problem scenario, ratings of effectiveness and number
of relevant means were based on the total response of the participant,
across
both
Two sets
ofsections.
MEPS items, each comprising 3 of the original 10 scenarios
described by Platt et al., were prepared. Set A contained scenarios describing (a) relationship difficulties with a boyfriend/girlfriend, (b) losing a
watch, and (c) making friends in a new neighborhood. Set B contained
scenarios describing (a) difficulties with a supervisor at work, (b) starting
a relationship with an attractive boy/girl, and (c) friends avoiding you.
Participants were randomly allocated to order A/B or B/A. Scenarios were
presented in the third person, with the protagonist of each story presented
as
the same sex
as the participant.
Participants’
responses
were recorded on audiocassette and transcribed
before rating. For each MEPS scenario, two dependent variables were
derived: the overall effectiveness of the participant’s response, which was
rated blind on a 7-point scale (1 � not at all effective to 7 � extremely
effective), and the number of relevant means (active problem-solving
steps) the participant produced. As described above, in both cases these
ratings were derived on the basis of the total response of participants to
each problem item. Transcripts were rated by two independent raters, both
of whom were blind to group status. Consistency between raters was
established on a random sample of 15% of the cases yielding coefficients
of � (54) � .84 (excellent) for number of relevant means and � (55) �
.68 (substantial) for ratings of effectiveness. Participants’ effectiveness
ratings and relevant means scores were summed across items administered
at the same stage of the experiment to create overall scores for
effectiveness and total number relevant means pre-and post-mood
induction.
Autobiographical Memory Test (AMT). Participants were presented one at
a time with a series of cue words, which were read to them by the
experimenter and also presented written on cards. For each cue word,
participants were asked to report an event that had happened to them that
the word reminded them of—a specific event, defined as an event that had
lasted less than a day and occurred at a particular time and place. Participants were additionally asked not to include memories from the preceding
week and to avoid repeating events described in response to previous cue
words. Three practice words were given to participants, with practice
continuing until specific memories had been recalled for at least two of
these three words. Participants were given 30 s to respond to each cue
word. Individuals’ responses to each cue word were recorded verbatim by
the
and also
recorded6on
audiotape
for laterinrating.
Twoexperimenter
sets of 18 words
(6 positive;
negative;
6 neutral
each) were used
as cues. In each set the positive, negative, and neutral words were matched
for frequency. Additionally, the positive and negative words were matched
in (high) emotionality, with the neutral words chosen to be low in
emotionality. Sets A and B were matched to one another in overall
frequency and emotionality of words.
Following previous studies, responses were later rated by the experimenter
as specific (events lasting less than a day); categoric (repeated events);
extended (events lasting longer than one day); semantic associates of the
cue word, and omissions (no response; details of scoring and procedures
for the AMT are available from the authors).
Procedure
After an initial introduction and opportunity for questions, participants
gave their written informed consent to participate in the study. The study
received ethical approval from the Oxfordshire Psychiatric Research
Ethics Committee.
group, F(2, 52) � 6.00, p � .005, partial � � .19, and a
significant interaction between time and group, F(4.38, 113.98) �
2.95, p � .02, partial � � .10. For happiness there was again a
main effect of time, F(2.39, 124.14) � 38.67, p � .001, partial
� � .43, a main effect of group, F(2, 52) � 6.27, p � .004,
partial � � .19, and an interaction between time and group that
was at trend level after applying the Greenhouse-Geisser
correction to adjust the degrees of freedom, F(4.78, 124.14) �
2.23, p � .06, partial � � .08. Post hoc pairwise comparisons
(Bonferroni) were used to further examine the interactions
between time and group for both despondency and happiness
ratings.
Differences in the pre-mood induction phase. There were no
significant differences between participants in levels of despondency or happiness at the beginning of the experimental session.
However, by Time 2 (pre-mood induction) participants in the
MDD-suic group reported significantly higher levels of despondency and lower levels of happiness than controls (both ps � .01)
and those in the MDD-no suic group (both ps � .05).
Effects of mood induction. In all three participant groups there was
a significant worsening of mood from Time 2 (pre-mood
induction) to Time 3 (post-mood induction), indicated by significant reductions in happiness (all ps � .002) and significant increases in despondency (all ps � .001). Immediately after the
induction, participants in the MDD-suic group were significantly
more despondent and less happy than individuals in the control
group (both ps � .008), but did not differ from individuals in the
MDD-no suic group. There were also differences at trend level
between the controls and the MDD-no suic group in both despondency and happiness post-mood induction.
Post-induction test phase. None of the groups changed significantly from Time 3 to Time 4 in either happiness or despondency
ratings, indicating that induced sad mood was largely maintained.
2
Measures. The study began with the SCID interview. Following this,
participants completed the MEPS and AMT on two occasions, once prior
to and once following a mood-induction procedure. The tasks were administered in the same order pre-and post-mood induction, with the MEPS
completed prior to the AMT. Following completion of all tasks, participants filled in a questionnaire booklet, including the BDI-II, BHS, BSS,
and BSSW. At the end of the experimental session, participants were
debriefed. Researchers ensured that any participants who had become
upset during the mood-induction procedure had returned to their normal
mood before departing.
Mood induction. Participants were informed that the purpose of the
mood-induction procedure was to induce a sad mood and that in order to
do this they would be asked to listen to music and to read cards containing
sad statements (40 Velten negative statements such as, “There are things
about me that I do not like.”). The mood-induction music (“Russia Under
the Mongolian Yoke” by Prokofiev, remastered at half-speed) was played
to the participant through loudspeakers for 8 min. Participants were asked
to read through the Velten statements and to identify those that were most
helpful to them in inducing a sad mood while trying to evoke the thoughts
and feelings described by the cards. Two mood-induction boosters were
given to sustain the sad mood during completion of the post-mood induction tasks, one immediately prior to the post-mood induction MEPS task
and one immediately prior to the post-mood induction AMT.
Results Participant
Characteristics
Depression. BDI-II scores for each group are shown in Table
1. Univariate analysis of variance (ANOVA) indicated a significant
main effect of group on current BDI-II score, F(2, 53) � 9.05, p �
.001. Post hoc tests (Bonferroni) indicated that although there was no
significant difference between the two formerly depressed groups, the
BDI-II score in the MDD-suic group was significantly higher than in
controls, MI-J � 7.87, SE � 1.86, p � .001.
Hopelessness. Current levels of hopelessness, as measured by the
20-item BHS, were compared across the three groups (see Table 1).
Univariate ANOVA indicated a main effect of group on current levels
of hopelessness, F(2, 53) � 6.98, p � .002, with post hoc tests
(Bonferroni) revealing that although there were no significant
differences between the two formerly depressed groups, the
MDD-suic group was significantly more hopeless than controls (MI-J
� 4.17, SE � 1.12, p � .001).
Worst-ever suicidality. Participants’ scores on the BSSW are
shown in Table 1. Univariate ANOVA indicated a main effect of
group, F(2, 53) � 56.28, p � .001, due to the fact that, as
expected, participants in the MDD-suic group scored significantly
higher than those in both the control group (MI-J � 13.32, SE �
1.37, p � .001) and in the MDD-no suic group (MI-J � 12.72, SE
� 1.51, p � .001).
2
2
2
2
2
MEPS Task
Number of relevant means. The number of means produced by
participants prior to the mood-induction procedure was similar in
each group (Controls: M � 24.9, SD � 6.56; MDD-no suic: M �
26.33, SD � 10.31; MDD-suic: M � 23.21, SD � 5.65).
Following the mood induction, the number of means produced
appeared to be somewhat lower in all groups (Controls: M �
22.64, SD � 6.03; MDD-no suic: M � 22.20, SD � 8.00;
MDD-suic: M � 19.11, SD � 6.68). A repeated measures
ANOVA conducted to examine the effect of the negative mood
induction on the number of relevant means indeed revealed a main
effect of time, F(1, 53) � 26.51, p � .001, partial � � .33, as a
result of participants producing fewer relevant
2
1
Visual Analog Mood Ratings
Figure 1A shows changes in participants’ ratings of happiness
and Figure 1B shows changes in participants’ ratings of despondency across the experimental session. Changes in despondency
and happiness ratings were examined separately using repeated
measures ANOVAs with time as the within-subjects factors and
group as the between-subjects factor. Effect sizes were calculated
using the partial eta squared statistic (partial � ), with .01 representing a small effect, .06 a moderate effect, and .14 a large effect.
Analysis of despondency revealed a main effect of time, F(2.19,
113.98) � 54.83, p � .001, partial � � .51, a main effect of
1
2
2
Mauchly’s test indicated that the data for both happiness and despondency were significantly nonspherical, so the Greenhouse-Geisser correction was applied to adjust the degrees of freedom where appropriate.
After controlling for BDI in the analyses of despondency change, the
main effect of time, F(2.21, 112.80) � 33.95, p � .001, partial � � .40,
and interaction between time and group F(4.42, 112.81) � 4.24, p �
.002, partial � � .14, remained significant. In the case of happiness
ratings, the main effect of time, F(2.38, 121.41) � 14.77, p � .001,
partial � � .23, remained significant, whereas the interaction between
time and group, F(4.76, 121.41) � 1.95, p � .095, was a trend.
Significant decreases in happiness from Time 2 to Time 3 were observed
in all groups (all ps � .003). However, there were no significant
differences between groups at any time point.
2
2
2
2
Figure
1. Mean
sum
scores of
Visual
Analogu
e Scale
(VAS)
happines
s
(A)
and
VAS
despond
ency (B)
ratings
at
pre-and
post-mo
od
inductio
nassess
ments in
controls,
previous
ly
depresse
d
individu
als
without
suicidal
ideation
(MDD-n
o suic),
and
previous
ly
depresse
d
individu
als with
suicidali
deation
(MDD-s
uic).
MDD �
major
depressi
ve
disorder.
Figure 2. Mean Means-End Problem Solving task problem-solving effectiveness pre-and post-mood induction
in controls, previously depressed individuals without suicidal ideation (MDD-no suic), and previously
depressed individuals with suicidal ideation (MDD-suic). MDD �major depressive disorder.
means post-mood induction. However, there was no significant
interaction between time and group, and no between-subjects
effect of group, indicating that all participant groups responded
similarly to the negative mood-induction procedure in this regard.
Problem-solving effectiveness. A repeated measures ANOVA
with group as the between-subjects factor and time as the
within-subjects factor revealed a main effect of time, F(1, 53)
�21.81, p �.001, partial � �.29, and a significant interaction
between time and group, F(2, 52) �5.67, p �.006, partial �
�.18. There was no between-subjects effect of group.
2
2
Post hoc pairwise comparisons (Bonferroni), used to examine the
interaction between group and time (shown in Figure 2), indicated
that the MDD-suic participants were significantly less effective in
problem solving post-mood induction, relative to their pre-mood
induction scores (Mpre �12.58, SD �2.22 vs. Mpost � 10.16, SD
�2.63; MI-J ��2.42, SE �.44, p �.001), whereas the
never-depressed controls (Mpre �12.50, SD �2.18 vs. Mpost � 11.77,
SD �2.79 and MDD-no suic group (Mpre �12.33, SD �
2.58 vs. Mpost �11.87, SD �2.13) showed no significant change.
Thus, individuals in the MDD-suic group experienced a greater
deterioration in problem solving than controls or nonsuicidal previously depressed participants. Next, we examined the difference
in effectiveness between the groups at Time 2 covarying out Time
1 effectiveness scores. In addition to the main effect of pre-mood
induction effectiveness, F(1, 52) �50.21, p �.001, partial � �
.49, there was a main effect of group, F(2, 52) �5.75, p �.006,
resulting from the fact that the MDD-suic group showed less
effective post-mood induction problem solving than both the
MDD-no suic group (MI-J ��1.90, SE �.64, p �.05) and the
control group (MI-J ��1.68, SE �.58, p �.02), which did not
differ from each other (MI-J ��.22, SE �.62, p �.1).
2
As discussed in the preceding sections, significant differences
between groups were identified in current BDI-II and BHS scores,
and in levels of happy and despondent mood during the pre-and
post-mood induction test phases. Pearson’s product moment correlations were computed between each of these variables and the
measure of pre-to post-mood induction effectiveness change,
separately in each participant group. There were no significant
correlations (all ps �.1), with the exception of a trend toward an
association between BHS score and effectiveness change in the
control group (r �.41, p �.06).
3
Autobiographical Memory
Exploration of the autobiographical memory data showed that in
most of the cases in which participants had not been able to come
up with a specific memory, responses took the form of omissions;
mean numbers of memories classified as extended, categorical, or
semantic associate were comparably small (mean numbers within
groups �1). This prevented comparison of different forms of
3
As an added precaution, we conducted repeated measures ANCOVAs
with group and order as between-subjects factors and time (pre-,
post-mood induction) as a within-subjects factor to examine the effect of
the mood induction on problem-solving effectiveness, controlling
separately for BDI, BHS, and the VAS measures. An ANCOVA including
only the previously depressed groups was also conducted to control for
length of longest episode of depression. In each case the interaction
between time and group remained significant (BDI: F(2, 49) �4.13, p
�.02, partial � �.14; BHS: F(2, 49) �4.04, p �.05, partial � �.14;
VAS measures: F(2, 45) �3.79, p �.03, partial � �.14; length of
episode: F(1, 31) �6.09, p �.02, partial � �.164.
2
2
2
2
overgeneral memories and further analyses were, consequently,
based on total numbers of specific memories retrieved. Means and
standard deviations of numbers of specific memories before and
after the mood induction are depicted in Table 3. Inspection of the
table shows that memory performance remained largely
unaffected by the mood induction in all three groups. A 2 � 3
repeated measures ANOVA with time (pre-vs. post-mood
induction) as within-subjects and group (control vs. MDD-no suic
vs. MDDsuic) yielded no significant main or interaction effects
(all ps � .1).
Autobiographical Memory and MEPS Effectiveness
In order to investigate possible moderating effects of memory
specificity, changes in problem-solving effectiveness were further
analyzed by dividing participants into those with baseline specificity scores greater than 14 or less than or equal to 14 (the overall
group median). A 2 � 2 � 2 repeated measures ANOVA with
time (effectiveness pre-vs. post-mood induction) as
within-subjects and specificity (high vs. low) and group (control
vs. MDD-no suic vs. MDD-suic) as between-subjects factors
showed a significant time � specificity interaction, F(1, 50) �
5.07, p � .05, partial � � .09. This interaction was due to
significant decreases in problem-solving effectiveness in
individuals with low memory specificity (MI-J � 1.73, SE � .31,
p � .001); there were no significant differences in those with high
memory specificity (MI-J � .57, SE � .40, p � .16). The
three-way interaction failed to reach significance, F(2, 50) �
1.66,
p �the
.20.
Because
differential activation of suicidality hypothesis related specifically to the group with a history of suicidal ideation,
we examined effectiveness decreases within each group. This
confirmed that differences were significant only in the previously
suicidal group. Although effectiveness of problem solving was
significantly impaired in previously suicidal individuals whether
they were high (MI-J � 1.40, SE � .57, p � .02) or low in
memory specificity (MI-J � 3.56, SE � .61, p � .001), the
impairment was more pronounced in the latter group.
Effectiveness changes in both of these subgroups are depicted in
Figure 3. A 2 (effectiveness: pre-vs. post-mood induction) � 2
(memory specificity: high vs. low) repeated measures ANOVA
yielded a significant interaction, F(1, 17) � 7.39, p � .01, partial
� � .30, confirming the moderating effect of overgenerality on
decreases in problem-solving effectiveness in previously suicidal
individuals. Results of the above analyses remained unchanged
when change in despondency and happiness were entered as
covariates, suggesting that
2
2
the moderating effect of memory specificity was not attributable
to possible influences on actual degree of mood change.
Discussion
The aim of this study was to investigate whether the differential
activation processes found in people who are vulnerable to
depressive relapse can be extended to suicidal ideation and
behavior. The study was motivated by the observation that not all
depressed patients are suicidal; hence, the need to specify in
greater detail what renders patients specifically vulnerable to
suicidality. We chose to examine interpersonal problem solving, a
feature of psychological performance that has consistently been
found to be associated with suicidality, and to examine it
following a mood challenge in formerly depressed participants
and never-depressed controls.
The results showed that, whereas the number of relevant means
produced in MEPS tasks was reduced following mood challenge
in all groups, the effectiveness of these solutions was selectively
more impaired in those who had been depressed and suicidal in
the past. Such suicidality was not merely a marker of having had
more episodes of depression, or of having had more serious or a
different subtype of depression, because we were able to check
that other symptoms did not distinguish the groups. This is
consistent with data from Mann et al.’s work showing that
patients with a diagnosis of MDD with a history of suicidal
behavior were indistinguishable on clinician ratings of severity of
depression, but were different on more cognitively focused
self-ratings (Beck’s Depression and Hopelessness scales, and
Linehan’s Reasons for Living inventory; Malone et al., 2000). The
present study extends such findings to patients in remission,
showing that when mood has returned to normal, cognitive
variables may return to normal, but those who have been
depressed and suicidal in the past are vulnerable to react
differentially to changes in mood—with greater deterioration in
problem-solving ability.
The current study extends differential activation theory in a
number of ways. First, it extends it from a general theory about
depressive relapse to the important specific problem of suicidal
ideation and vulnerability. Second, it extends the range of relevance of the theory from purely cognitive measures (attitudes,
memory, and attentional bias) to a behavioral measure: problem
solving. To our knowledge this is the first study to apply differential activation theory to a behavioral deficit, a deficit that has
been found to be an important signature of suicidality. Third, it
extends differential activation by suggesting that, in some cases,
Table 3
Specific Memories Pre-and Post-Mood Induction in Control Group and Previously Depressed
Participants
a
b
c
Control MDD-no suic MDD-suic Specific memories M SD M SD M SD
Pre-mood induction 13.6 2.4 12.9 2.9 14.5 2.0 Post-mood induction 13.6 3.2 12.6 2.9 13.6 3.0
Note. MDD � major depressive disorder; suic � suicidality history. Control group, n � 22. Participants with
history of MDD but no suic, n � 15. Participants with both history of MDD and suic, n � 19.
a
c
b
Figure 3. Mean Means-End Problem Solving task problem-solving effectiveness pre-and post-mood induction
in formerly depressed subjects with suicidal ideation scoring high (n � 10) or low in memory specificity (n �
9).
the extent to which mood affects behavior can be moderated by
other variables—in this case, by specificity in autobiographical
memory. We predicted this on the basis that inability to retrieve
event-specific knowledge would prevent a person from bringing
evidence to bear of effective solutions from the past.
But there remains a puzzle. Why did the previously suicidal
people not also show impairments on the number of relevant
means they produced in response to the MEPS items? Interestingly, our previous research with suicidal patients has also found
that memory specificity is correlated more highly with effectiveness than with the number of relevant means (Pollock &
Williams, 2001, p. 393). However, memory alone cannot explain
these results, since the groups did not differ in their specificity of
memory. What then can account for this pattern of results? Recall
that the differential activation model suggests that suicidality represents one of the most severe forms of negative self-referent
global patterns of thinking. Impaired problem solving is one behavioral outcome that becomes associatively linked with this negative processing pattern. In those with a history of suicidal ideation, therefore, the mood challenge begins to reactivate the entire
pattern of negative thinking. It is possible that the “effectiveness”
component of the MEPS is more sensitive to subtle shifts in the
quality of problem solving, a shift from external task-focused
problem orientation toward more internally focused, ruminative,
or affect-regulating strategies. According to this account, those
with a suicidal history remain able to produce some means toward
a problem solution, but they tend to recast the problem in terms of
coping with themselves and their emotions. Indeed, there is evidence that inducing a ruminative response style impairs problem
solving in its own right (Lyubomirsky & Nolen-Hoeksema, 1995;
Watkins & Baracaia, 2002). Only further research will show us if
reactivation by mood challenge is equivalent (in terms of under
lying process and observable outcome) to reactivation by rumination induction in previously suicidal individuals.
What are the clinical implications? The results show that problem
solving deteriorates in response to low mood in those who have
been suicidal in the past even if it appears, before the mood
challenge, that their problem solving is intact. First, it implies that
psychological treatments that focus on remedying behavioral deficiencies may have a hard time engaging suicidal patients once
the crisis is past not only because they may be unwilling to engage
in therapy in general, but also because their problem solving,
which is the focus of most psychological approaches (Hawton et
al., 1998), has returned to normal or near normal levels. Second, it
implies that problem solving may be impaired not only when a
person comes up against a “real” problem in daily living, but also
when their mood is disturbed for any reason. This implies that
clinicians should be on the lookout for endogenous changes (such
as sleep disturbance) that may not themselves be the result of life
events, but which may exacerbate mood and lead to impaired
problem solving—especially in patients who have been suicidal
previously when in an episode of depression.
It is important to realize the limitations of the study we have
reported. First, the numbers were relatively small, so it requires
replication. Small numbers introduce the possibility of Type II
errors, so that we may have missed some findings that would have
become apparent with larger numbers. Second, the pattern of
autobiographical memory data showing no difference between
previously depressed and never-depressed groups contradicts
some previous research (Williams, 2004). This may represent
population differences between the studies that only further
research can resolve. Third, we followed previous studies that
compare previously depressed with never-depressed people, and
did not use “neutral mood induction” control groups. Thus, it
remains possible
that the observed effects on problem solving were not specifically
due to reactivity to mood per se, but to other factors such as
fatigue, loss of motivation, or preoccupation with the pretest
assessment material. Indeed, it is interesting to note that the
MDDsuic group showed mood change before the other two
groups and prior to the experimental mood induction, although
covarying out pre-mood-induction mood did not alter the results.
Fourth, although we focused on the fact that specific memory
protected against the differential activation effects in those with a
history of suicidal ideation, this protective effect was shown
across all groups, so this finding should be treated cautiously.
Finally, our findings appear to be directly relevant to vulnerability
for further suicidal behavior, but this claim would require a
prospective study in which people at risk for suicidal behavior
were followed up to see if their future suicidality was predicted by
their response to mood challenge.
However, a first test of whether differential activation theory
applies in any new context requires the demonstration of a vulnerability factor that is latent in the absence of disturbed mood,
but becomes manifest in the context of such disturbance. This
study shows that this may indeed be the case for problem-solving
effectiveness in previously suicidal patients; that such latent
vulnerability is not shown by formerly depressed patients who
have not been suicidal; and that the effect is partly moderated by
the trait specificity in autobiographical memory.
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Received July 17, 2004 Revision received
November 10, 2004 Accepted November
18, 2004 �