Comparing features of bipolar disorder to major depressive disorder in a tertiary mood disorders clinic.
BACKGROUND
We sought to describe features that distinguish individuals with bipolar disorder from major depressive disorder.


METHODS
A retrospective chart review of adult outpatients (N = 1000) seeking evaluation and treatment was conducted at the Mood Disorders Psychopharmacology Unit (MDPU), University Health Network, University of Toronto between October 2002 and November 2005 was conducted. Sociodemographic parameters, illness-characteristics and therapeutic interventions were evaluated and compared.


RESULTS
The MDPU referring diagnosis were major depressive disorder (52%), bipolar disorder (29%), and unspecified (19%). Of all individuals with a non-bipolar entry diagnosis (n = 699), 23% (n = 159) were subsequently diagnosed with bipolar disorder (p < 0.001); the majority of whom (n = 117, 74%) received a non-bipolar I disorder diagnosis [e.g. bipolar II disorder (n = 71); bipolar NOS disorder (n = 46) (p < 0.001)]. Higher rates of unemployment/disability, previous depressive episodes, psychiatric hospitalization, comorbid hypertension, and lifetime substance use disorders, as well as an earlier age of illness-onset were more frequently endorsed by individuals with a diagnosis of bipolar disorder. Fifteen percent of individuals who were newly-diagnosed with bipolar disorder reported a history of antidepressant-associated mania.


CONCLUSIONS
The majority of individuals with a newly-diagnosed bipolar disorder at this tertiary center have a non-bipolar I disorder (i.e., bipolar spectrum). Several indices of illness severity differentiate individuals with bipolar disorder from major depressive disorder.
Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, ON, Canada. roger.mcintyre@uhn.on.ca
Roger S
RS
McIntyre
Joanna K
JK
Soczynska
Deborah
D
Mancini
Hanna O
HO
Woldeyohannes
Jakub Z
JZ
Konarski
Sidney H
SH
Kennedy
D000328:Adult; D000554:Ambulatory Care Facilities; D001714:Bipolar Disorder / Q000175:diagnosis*; D003710:Demography; D003865:Major Depressive Disorder / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D019964:Mood Disorders / Q000628:therapy*; D012189:Retrospective Studies