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.
McIntyre
Roger S
RS
Mood Disorders Psychopharmacology Unit, University Health Network, University of Toronto, Toronto, ON, Canada. roger.mcintyre@uhn.on.ca
Soczynska
Joanna K
JK
Mancini
Deborah
D
Woldeyohannes
Hanna O
HO
Konarski
Jakub Z
JZ
Kennedy
Sidney H
SH
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