Classification of mental
disorders.
Classification of mental
Disorders.
• All systems of mental disorders and diagnosis
stem from the work of Kraepelin.
• He claimed certain groups of symptoms occur
together often, thus allowing us to call them
diseases or syndromes.
• He regarded each mental illness as distinct
from all others with its own origins,
symptoms, course and outcomes.
Classification cont…
• He originally classified two major groups:
• Dementia praecox (Schizophrenia)
• Manic-depressive psychosis (faulty
metabolism).
• This helped to establish the organic nature of
mental disorders and formed the basis of the
Diagnostic statistical manual of mental
disorders (DSM).
Classification cont..
• This helped to establish the organic nature of
mental disorders and formed the basis of the:
• Diagnostic statistical manual of mental
disorders (DSM). The APA’s official classification system
• The International classification Of Diseases
(ICD). Published by the World Health Organisation (WHO)
• His classification is also embodied in the Mental health Act
(1983). The act contains three major categories of mental
disturbances.
• Mental illness, personality Disorder, and Mental impairment.
DSM-IV-TR & ICD-10.
• DSM-IV-TR
• Larger no. of
discrete categories.
• Uses a multi-axial
system.
• Uses term psychotic.
• ICD-10
• More general
categories.
• Generally single axis.
But uses broad aetiology.
Uses term neurotic.
DSM-IV-TR
• The inclusion of the axes reflect the
assumption that most disorders are
caused by the interaction of:
• Biological
• Sociological
• Psychological factors.
• The patient is assessed more broadly
giving a more global in depth picture.
DSM-IV-TR (1994)
• DSM IV (1994):
Ø Effort to develop a consistent worldwide system of
classification that would be compatible with the ICD10.
Ø Huge review of all research on psychopathology to
update the classification system.
Ø Distinction between organically based disorders and
psychologically based disorders was eliminated.
Ø Increased considerations of cultural factors.
Diagnostic assessment: Clinical History
 Onset, duration and
severity of current
symptoms
Ø Previous mental
illness
Medical history
Ø Childhood history
Ø Occupational
functioning
Educational history
Ø Marital and
relationship history
Ø Family history
Ø Religion
Ø Psychosexual
history
Ø Current living
situation
Assessment Procedures

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·
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•
Mental Status Examination
Projective tests e.g. Rorschach,
TAT.
Objective tests e.g. MMPI
Organic tests e.g. Blood tests, CAT
scan
Collateral information
DSM-IV Classification.
1. Disorders usually first diagnosed in infancy,
childhood or adolescence
2. Delirium, Dementia & amnestic, & other
cognitive disorders
3. Mental disorders due to a general medical
condition
4. Substance related disorders
5. Schizophrenia & other psychotic disorders
6. Mood disorders
7. Anxiety disorders
DSM-IV Classification.
9. Somatoform disorders
10.Factitious disorders
11.Dissociative disorders
12.Sexual & Gender identity disorders
13.Eating disorders
14.Sleep disorders
15.Impulse control disorders not elsewhere classified
16.Adjustment disorders
17.Personality disorders
18.Other conditions that may be a focus of clinical
attention
DSM-IV-TR
The five axes of the DSM-IV-TR
.
• Axis I Clinical syndromes. (All mental disorders & criteria for
rating them except personality disorders/mental retardation,
also abuse/neglect)
• Axis II Personality disorders, Mental retardation. (Life long
deeply ingrained, inflexible & maladaptive)
• Axis III General medical condition. (Any medical condition that
could effect the patients mental state.)
• Axis IV Psychosocial & environmental problems. (Stressful
events that have occurred within the previous year)
• Axis V global assessment functioning. (How well the patient
performed during the previous year)
ICD-10
• It was agreed whilst being constructed that because of the
incomplete and often controversial state of knowledge about the
aetiology of most psychiatric disorders, the classification would
be worked out on a descriptive basis.
• Implying that disorders should be grouped according to
similarities and differences of symptoms and signs so that a
particular disorder should occur in only one place.
• However it soon became clear this would not appeal to clinicians
(they like to make aetiology very important!!) This therefore
makes the ICD-10 impure from a taxonomic point of view, but
still more likely to be used by clinicians than the DSM-IV-TR.
The use of diagnostic criteria
• Both systems have introduced explicit operational
criteria for diagnosis. That is:
• For each disorder there is a specified list of
symptoms, all of which must be present , for a
specified period of time, in relation to age and
gender, stipulation as to what other diagnoses
mustn’t be present and the personal and social
consequences of the disorder.
• The aim is to make diagnosis more reliable and valid
by laying down rules for the inclusion or exclusion of
cases.
Problems with the classification
of mental disorder.
• Diagnosis is the process of identifying a
disease and allocating it to a category on the
basis of symptoms and signs.
• Therefore any system that psychiatrists
cannot agree upon has little value (Interrater /inter- judge reliability) and represents
a fundamental requirement of any
classification system.
• What are your thoughts
Example of Diagnosis:
• Patient: Johnnie Walker
– Axis I: Major depressive Disorder
– Axis II: Narcissistic Personality Disorder
– some features only
– Axis III: Poor liver functioning, frequent
migraines.
– Axis IV: Recently retrenched
– Axis V: 65
Problems with DSM
classification.
• Labeling:
Ø
Ø
Ø
Ø
Tends to be reductionistic.
May lead to stigmatisation, or person
taking on the sick role and identifying
with the label.
Labels are “sticky”. (Rosenhan study and
2005 Darwin Awards)
Instrument of social control: gives mental
health professionals control over
people’s lives.
Alternate approaches:
Dimensional system
• More holistic: considers a person's
functioning on a number of different
dimensions, which would reflect their
strengths and weaknesses.
• Rating on a continuum scale may be able to
reflect the graduations between normality
and abnormality.
• Database of profiles may be used to
construct a new classification system.
Problems with the classification
of mental disorder.
• Early studies have shown time after time poor
diagnostic reliability. WHY???
• One reason may lie in the fact that information elicited
in interviews vary widely, also the interpretation of the
said information is largely subjective.
• Secondly trained psychiatrist from different countries
showed great variation in their interpretations.
• E.g. UK-US Diagnostic project showed American &
British psychiatrists the same videotaped clinical
interviews and asked them to make a diagnosis. New
York psychiatrists diagnosed schizophrenia twice as
often, while the London psychiatrists diagnosed
mania and depression twice as often.(Cooper et al
1972)
The International Pilot Study of
Schizophrenia (WHO,1973)
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Compared psychiatrists in nine countries
Columbia
Czechoslovakia
Denmark
England
India
Nigeria
Taiwan
USA
USSR.
There was substantial agreement between 7 of the 9 the
exceptions were USA & USSR which both seemed to have
unusually broad concepts of schizophrenia (thus confirming
Coopers results!!)
So how do we improve reliability?
• If the professionals are trained to use
the same standardised interview
schedules E.g. Present State
Examination (PSE) Wing et al (1974).
The function of classification
• Inform effective treatment selection
• Administrative functions e.g. Medical aids,
legal system.
• Provides vocabulary for professionals to
communicate. Clinical shorthand.
• Provides information on prognosis.
Problems with the Classification
system.
• Co-morbidity: e.g. depression and anxiety, psychotic
disorders and mood disorders. Questionable validity?
• Reification: an alcoholic vs. a person with an alcohol abuse
disorder.
• Discounts graduations between normality and abnormality.
Tends to focus on pathology.
• Descriptive nature of system may hamper theoretical
development and research on etiology.
• Focus on reliability to the detriment of validity
Validity of Diagnostic system
Validity: the degree to which the category reflects the
disorder it seeks to describe.
– Construct validity: whether the symptoms chosen as
criteria for a disorder are consistently associated with
the disorder.
– Descriptive validity: The extent to which the diagnostic
classification provides significant information about the
individuals placed in the category. Frequent criticism.
– Predictive validity: extent to which a diagnosis is able to
predict the course of the disorder and the efficacy of
different types of treatment
Reliability of diagnostic
systems:
• Reliability: The extent to which different
clinicians agree in identifying a disorder.
• Validity and reliability are often at odds with
each other. DSM-IV accused of sacrificing
validity for increased reliability.
• NB: Research methods trade off between
reliability and validity when using either lab or
field experiments.
Being sane in an insane place!!!
• Rosenhan (1973)
• 8 ‘normal’ people presented themselves at the
admissions office of 12 different psychiatric hospitals in
the USA.
• Hearing voices,etc all 8 admitted with
(schizophrenia/manic depression).
• Eventually discharged with diagnosis of schiz/Manic dpress in remission.
• The only people suspicious of them were the patients it
took between 7 and 52 days for them to convince staff
they were well enough to be discharged.
But there’s more!!!
• In a second study members of a teaching
hospital were advised about the results of the
original study and warned they would receive
pseudo patients trying to gain entry. Each
member of staff were asked to rate who was
genuine and who was the fake.
• 193 patients were admitted
• 41 were confidentially alleged to be impostors
• 23 were suspected by one psychiatrist
• 19 were suspected by another psychiatrist
and another member of staff.
And the prize goes to??????
• All were genuine patients!!!!!!!
• What conclusion can be drawn about
psychiatric diagnosis form Rosenhans
study?
• Are there features of the study that
would make generalisations difficult?