A clinical study of various diagnostic classification systems in bipolar spectrum disorders :
especially rare forms.
Abstract
Objective: There has been a dearth in data as to which system of classification stands most
efficient in detecting and diagnosing bipolar spectrum disorders clinically and this needed
to be researched. The aim of the study was to compare various new diagnostic classification
systems (Jules Angst classification and Akiskal’s classification) in detecting/diagnosing
bipolar spectrum disorders especially rare forms) with most widely used methods of
classifications like DSM-IV-TR and ICD-10. Methods: This was a cross sectional study of
80 patients clinically suffering from bipolar mood disorder attending the psychiatry
outpatient department or those admitted in the psychiatry wards in whom four diagnostic
classification systems were compared. Results: All the 59 patients with classic bipolar
symptoms were diagnosed by the four diagnostic classification systems. DSM-IV-TR and
ICD-10 classification classified all the 21 patients of less common forms of bipolar disorder
into some or the other category. Akiskal’s classification classified 19 out of 21 patients
(90.48%). Jules Angst’s classification classified only 4 of the 21 (19.04%) patients of the less
common forms of bipolar disorder. Conclusions: All the diagnostic systems are equally
good while classifying patients with classic bipolar symptoms. DSM-IV-TR and ICD-10
proved to be the most efficient in classifying less common forms of bipolar disorder. Jules
Angst classification lacks diagnostic subcategories like schizoaffective disorder; substance
induced mood disorder and dementia with psychotic features, whereas Akiskal’s
classification lacks subcategories for cyclothymia.
Keywords : Bipolar disorder, diagnosis, DSM-IV-TR, ICD-10, Jules Angst’s classification,
Akiskal’s classification
LIST OF ABBREVIATIONS USED
BP I – Bipolar I
BP II – Bipolar II
UP – Unipolar
BP – Bipolar
BMD – Bipolar Mood Disorder
BPAD – Bipolar Affective Disorder
BMD-NOS – Bipolar Mood Disorder – not otherwise specified
1
Introduction
The concept of bipolar spectrum disorders has evolved over the last few
years as propounded by Akiskal and Jules Angst and claims to be more efficient in detecting
even rare and less common forms of bipolar disorders [1]. However, there has been no published
data quantifying the claim. There has been a dearth of data as to which system of classification
stands most efficient in detecting and diagnosing bipolar spectrum disorders clinically. This
study was conducted in a municipal general hospital in Mumbai to compare various diagnostic
classification systems in detecting/diagnosing bipolar disorders (especially rare forms).
Methodology
This was a cross sectional study conducted by the department of
psychiatry in a tertiary care municipal teaching hospital. The patients were recruited from the
psychiatry ward and the outpatient department of the hospital. The sample consisted of 80
patients clinically suffering from bipolar mood disorder attending the psychiatry outpatient
department or those admitted in the psychiatry wards. The patients were interviewed in detail
with their relatives and enrolled in the study if they satisfied the inclusion criteria. The inclusion
criteria were- 1) Patients of either sex and of any age with their relatives willing to participate in
the study by signing an informed consent form; 2) Patients with symptoms and history
suggestive of a diagnosis of bipolar mood disorder; 3) Patients with adequate and reliable
objective data. The exclusion criteria were- 1) Patients lacking reliable objective data; 2) Patients
having diagnosis of any other medical disorder likely to alter the clinical course of psychiatric
illness; 3) Patients not suitable for the study for any other reason as per the discretion of the
investigator.
A special proforma was prepared to collect the socio-demographic data,
clinical profile of the patient, phenomenology, total duration and details of course of psychiatric
illness etc. The other materials used for the assessment of patients included- The Jules Angst’s
classification for bipolar spectrum disorders, Akiskals classification for bipolar spectrum
disorders, DSM-IV TR and ICD-10. The patients and/or relatives were explained the nature of
the study. A written informed consent was taken from the patient and/or relatives. Patients with
their relatives were then interviewed using the special proforma and relevant data was collected
for the individual case. A complete retrospective and current evaluation of the case histories was
done and an attempt to classify each case with different diagnostic systems for bipolar disorders
(viz. DSM-IV-TR, ICD-10, Akiskal’s and Jules Angst classification) was made. A study of the
phenomenological aspects of the disorder and a comparative study of these classifications was
then done.
All the 80 patients were divided into two groups according to the
symptoms and compared with various diagnostic systems.1) Classic Bipolar Group: Patients
having discrete episodes of mania/s and patients having episodes of mania and depression in the
course of their illness. 2) Others Group (less common forms of bipolar disorders): patients with
episodes of hypomania, hypomania and mild depression, substance induced mood symptoms etc.
Written approval for the study was obtained from the institutional ethics committee.
Results
The mean age of patients with classic bipolar disorder was 35 years
(range of 16-65 years) while it was 44 years ((with a range of 23-80 years) in patients with less
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common forms of bipolar disorder. Majority of the patients were male (72.5 %) in the study
(Table 1). All the 59 patients with classic bipolar symptoms were diagnosed by the four
diagnostic classification systems. Thirty three (33/59) patients with classic bipolar symptoms
were diagnosed as Bipolar-I with psychotic features by Jules Angst classification. All the 59
patients were diagnosed as Bipolar-I by Akiskal’s classification. Of the 59 patients with classic
bipolar symptoms, 50 were diagnosed as Bipolar Mood Disorder – I (BMD-I) mania by
DSM-IV-TR and 21were diagnosed as Bipolar Affective Disorder (BPAD) manic without
psychotic symptoms by ICD-10. as BMD-I in DSM-IV-TR, BPAD in ICD-10 and Bipolar-1 in
Jules Angst and Akiskal’s classification. Findings in the table below reveal that all the diagnostic
systems are equally good in classifying patients with classic bipolar symptoms (Table 2).
Thirteen (13/21) patients with persistent psychotic features and intermittent
affective symptoms formed the largest proportion (61.91%) in the group of the less common
forms of Bipolar disorders. Akiskal classified them as Bipolar-1/2 while DSM-IV-TR and
ICD-10 diagnosed them as Schizoaffective disorder. Jules Angst classification was deficient of
any sub category for patients with such symptoms and hence these were left undiagnosed (Table
3). One patient with recurrent episodes of hypomania and mild depressions was diagnosed as
having Cyclothymic disorder in the Jules Angst classification, DSM-IV-TR and ICD-10
classification while the same remained undiagnosed in Akiskal’s classification as it does not
mention any subcategory for such patients. One patient who had affective symptoms associated
with use of substance was diagnosed as having Bipolar-III ½ in Akiskal classification, as
Substance induced mood disorder In DSM-IV-TR and Persistent mood/affective
disorder-unspecified in ICD-10. Jules Angst classification lacked any such category and hence
the patient remained undiagnosed. Two patients with dementia having affective symptoms were
diagnosed as Bipolar-6 in Akiskal’s classification, as Bipolar Mood Disorder – not otherwise
specified (BMD-NOS) in DSM-IV-TR and as Unspecified affective disorders in ICD-10. These
patients missed the diagnosis in Jules Angst classification. A patient with persistent hypomanic
symptoms and intermittent psychotic symptoms was diagnosed as BMD-NOS in DSM-IV-TR
and Unspecified affective disorders in ICD-10, while it remained undiagnosed in the Jules Angst
and Akiskal’s classification. Overall, as far as diagnosing 21 bipolar patients of the less common
forms was concerned the DSM-IV-TR and ICD-10 proved to be the most efficient as they
classified all the 21 patients as bipolar disorders belonging to some or the other category.
Akiskal’s classification based on the concept of bipolar spectrum classified 19 out of 21 patients
(90.48%). Jules Angst’s classification classified only 4 of the 21 (19.04%) patients of the less
common forms of bipolar disorder.
All the 80 patients in the study were classified by DSM-IV-TR classification
and ICD-10 classification. Jules Angst classification classified 63 (78.75%) while Akiskals
classification classified 78 (97.50 %) of the 80 patients included in the study. Seventeen (21.25
%) patients did not receive any diagnosis by Jules Angst classification while 2 (2.50%) patients
did not receive any diagnosis by Akiskals classification (Table 4).
Schizoaffective disorder was the most common diagnosis (13 patients) which
was not classifiable by Jules Angst classification besides substance induced mood disorder
(1 patient), dementia with affective features (2 patients) and BMD-NOS/Unspecified affective
disorders (1 patient). Akiskal’s classification could not classify 1 patient of cyclothymia and
1patient of BMD-NOS / Unspecified affective disorders (Table 5).
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Discussion
The organization of the mood disorders in our current diagnostic system tends to
confound polarity and cyclicity, negatively impacting clinical, genetic, and pharmacological
research. Thus, in clinical research on unipolar-bipolar differences, the two groups are rarely
matched for cyclicity [2]. The diagnosis of hypomania poses further problems. First, there is a
growing movement to simply lower the admittedly arbitrary time criterion for hypomania.
Second, symptoms of mood elevation may not be severe enough to satisfy the DSM–IV
checklist, yet they are still recorded in patient interviews. Third, the term ‘hypomania’ is misused
widely to describe mania itself. None of this would matter greatly if the distinction between
bipolar and unipolar disorders had no implication for treatment. However, authors have found
that antidepressants were used earlier and more frequently than mood stabilizers in patients with
bipolar II disorder, and that almost a quarter of patients experienced a new or worsening
rapid-cycling course attributable to antidepressant prescription [3].
The two-dimensional bipolar spectrum described by Angst comprises a
continuum of severity from normal to psychotic and a continuum from depression, via three
bipolar subgroups to mania. This combination of dimensional and categorical principles for
classifying mood disorders may help alleviate the problems of under diagnosis and under
treatment of bipolar disorders. Two-dimensional mood/affective spectrum (does not include
schizoaffective disorder, as a transition to the schizophrenic spectrum). The precise relationship
of personality disorders to the disease spectra is uncertain and an unsolved general problem of
psychiatric classification. BP-I (-II), bipolar-I disorder type I (II); D, major depression, d, minor
depression; M, mania; m, hypomania; MDD, major depressive disorder; RBD, recurrent brief
depression; symptoms [4].
Physicians inevitably encounter patients with bipolar disorders, often when the
patient is depressed. For most of these patients, the attendant elevations in mood fall short of
mania. Such milder periods of expansive mood, hypo manias, may go unrecognized unless the
physician specifically queries the patient to uncover them. In addition, patients with bipolar
disorders often manifest other distinctive characteristics. An understanding of these hints of
bipolarity is helpful to clinicians treating depressive illness. Patients with bipolar disorders are at
risk for treatment complications caused by the administration of antidepressants without the
concurrent use of mood stabilizers, such as lithium carbonate, Valproate sodium, and
Carbamazepine. Such complications include exacerbation of hypomania or mania, induction of
refractory states, and, perhaps, rapid cycling or mixed states [5].
Kraepelin’s view from the previous turn of the century of affective
disorders, i.e., comprising both UP (unipolar depressive disorders) and BP (bipolar disorder or
the bipolar disorder spectrum) in current terminology, as a broad panorama of variants of
manic-depressive disorders, finds support in modern research [6-11]. It is above all the
discoveries of the high prevalence of bipolar II (BP II) and other bipolar spectrum disorders
[12-14] and the new knowledge of highly frequent conversion of unipolar (UP) to bipolar (BP)
[11, 15] that lend support to Kraepelin’s view. There is, however, also support for the view that
UP and BP can be conceived of as partially separate categories [6]. The courses of BP and UP
differ in terms of younger debut age and more frequent recurrences of the former [15]. In terms
of courses and symptoms, BP II is to a much higher degree a depressive disorder than bipolar I
(BP I), in that periods of manifest or subsyndromal depression relative to periods of
hypomania/mania are more than 10 times longer in BP II than in BP I [16]. Symptomatically BP
II and UP are different in that hypomanic episodes occur only in the former, while BP II differs
4
symptomatically from BP I in that only hypomania, not mania and often psychosis occurs.
The age of onset of bipolar disorder varies greatly. The age range
for both bipolar I and bipolar II is from childhood to 50 years, with a mean age of approximately
21 years. Most cases commence when individuals are aged 15-19 years. The second most
frequent age range of onset is 20-24 years. Some patients diagnosed with recurrent major
depression may indeed have bipolar disorder and go on to develop their first manic episode when
older than 50 years. They may have a family history of bipolar disorder. However, for most
patients, the onset of mania in people older than 50 years should lead to an investigation for
medical or neurologic disorders such as cerebrovascular disease [17].
Detection and diagnosis of bipolarity in mood disorders assumes prime
importance for the sake of appropriate treatment to be initiated right from the start of the illness.
The most widely used classifications for diagnoses; the DSM-IV-TR and ICD-10 have always
been under the critical eye of investigators for their ability to pick up bipolarities and clinical
applicability in diagnosing bipolar disorders. Akiskal’s concept of the bipolar spectrum proposes
to be a better system of diagnoses to classify bipolar disorders especially the rarer forms.
Similarly the concept of bipolar spectrum given by Jules Angst claims the same. There has been
a lack of evidence to quantify the claims. A dearth in data to evaluate the conceptual and
phenomenological validity of the bipolar spectrum has always been felt. The data for a
comparison of available systems of diagnoses to identify, diagnose and classify bipolar disorders
has been scarce. Literature on studies testing the conceptual validity of the bipolar spectrum by a
comparison with currently used diagnostic systems like the DSM-IV-TR and ICD-10 to diagnose
and classify bipolar systems clinically was found to be deficient.
Conclusions
All the diagnostic systems are equally good while classifying patients with classic
bipolar symptoms. However, in case of the less common forms of bipolar disorder, a marked
difference was observed among the diagnostic systems in their efficacy to clinically diagnose
bipolar disorder. Patients with rare and new forms of bipolar symptoms can be included in
categories like BMD-NOS and Unspecified affective disorders (in DSM-IV-TR and ICD-10
respectively), so that they do not miss a diagnosis of bipolar disorder for the lack of any
particular diagnostic subcategories. Such subcategories are therefore useful and recommended in
classifications like Akiskal and Jules Angst to make them clinically more efficient as diagnostic
systems for bipolar disorders.
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