Are there subtypes of bipolar depression?
To investigate for subtypes of bipolar depression using latent class analysis (LCA).



Participants were recruited through a bipolar disorder (BD) clinic. LCA was undertaken using: (i) symptoms reported on the SCID-IV for the most severe lifetime depressive episode; (ii) lifetime illness features such as age at first depressive and hypo/manic episodes; and (iii) family history of BD and unipolar depression. To explore the validity of any demonstrated 'classes', clinical, demographic and treatment correlates were investigated.



A total of 243 BD subjects (170 with BD-I and 73 with BD-II) were included. For the combined sample, we found two robust LCA solutions, with two and three classes respectively. There were no consistent solutions when the BD-I and BD-II samples were considered separately. Subjects in class 2 of the three-class solution (characterised by anxiety, insomnia, reduced appetite/weight loss, irritability, psychomotor retardation, suicidal ideation, guilt, worthlessness and evening worsening) were significantly more likely to be in receipt of government financial support, suggesting a particularly malign pattern of symptoms.



Our study suggests the existence of two or three distinct classes of bipolar depression and a strong association with functional outcome.
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.|Clinical and Health Psychology Research Initiative (CaHPRI), School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW, Australia.
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Perich
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.
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Hadzi-Pavlovic
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.
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Frankland
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.|Berghofer Queensland Institute of Medical Research, Brisbane, Qld, Australia.
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Breakspear
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.
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Loo
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.
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Roberts
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.
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Holmes-Preston
School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.|Black Dog Institute, Sydney, NSW, Australia.
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Mitchell
D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000523:psychology*; D001315:Australia; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000523:psychology; D003865:Major Depressive Disorder / Q000523:psychology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D059020:Suicidal Ideation; D055815:Young Adult
bipolar depression; latent class analysis; probabilistic; subtypes