Axis I psychiatric comorbidity and its relationship to historical illness variables in 288 patients with bipolar disorder.
OBJECTIVE
Bipolar disorder often co-occurs with other axis I disorders, but little is known about the relationships between the clinical features of bipolar illness and these comorbid conditions. Therefore, the authors assessed comorbid lifetime and current axis I disorders in 288 patients with bipolar disorder and the relationships of these comorbid disorders to selected demographic and historical illness variables.


METHODS
They evaluated 288 outpatients with bipolar I or II disorder, using structured diagnostic interviews and clinician-administered and self-rated questionnaires to determine the diagnosis of bipolar disorder, comorbid axis I disorder diagnoses, and demographic and historical illness characteristics.


RESULTS
One hundred eighty-seven (65%) of the patients with bipolar disorder also met DSM-IV criteria for at least one comorbid lifetime axis I disorder. More patients had comorbid anxiety disorders (N=78, 42%) and substance use disorders (N=78, 42%) than had eating disorders (N=9, 5%). There were no differences in comorbidity between patients with bipolar I and bipolar II disorder. Both lifetime axis I comorbidity and current axis I comorbidity were associated with earlier age at onset of affective symptoms and syndromal bipolar disorder. Current axis I comorbidity was associated with a history of development of both cycle acceleration and more severe episodes over time.


CONCLUSIONS
Patients with bipolar disorder often have comorbid anxiety, substance use, and, to a lesser extent, eating disorders. Moreover, axis I comorbidity, especially current comorbidity, may be associated with an earlier age at onset and worsening course of bipolar illness. Further research into the prognostic and treatment response implications of axis I comorbidity in bipolar disorder is important and is in progress.
Stanley Foundation Bipolar Treatment Outcome Network, Department of Psychiatry, University of Cincinnati College of Medicine, OH 45267-0559, USA. mcelroys@email.uc.edu
S L
SL
McElroy
L L
LL
Altshuler
T
T
Suppes
P E
PE
Keck
M A
MA
Frye
K D
KD
Denicoff
W A
WA
Nolen
R W
RW
Kupka
G S
GS
Leverich
J R
JR
Rochussen
A J
AJ
Rush
R M
RM
Post
D000328:Adult; D017668:Age of Onset; D000368:Aged; D000553:Ambulatory Care; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology*; D015897:Comorbidity; D005190:Family; D001068:Feeding and Eating Disorders / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D011379:Prognosis; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology