Influence of sub-syndromal symptoms after remission from manic or mixed episodes.
BACKGROUND
Sub-syndromal symptoms in bipolar disorder impair functioning and diminish quality of life.


OBJECTIVE
To examine factors associated with time spent with sub-syndromal symptoms and to characterise how these symptoms influence outcomes.


METHODS
In a double-blind randomised maintenance trial, patients received either olanzapine or lithium monotherapy for 1 year. Stepwise logistic regression models were used to identify factors that were significant predictors of percentage time spent with sub-syndromal symptoms. The presence of sub-syndromal symptoms during the first 8 weeks was examined as a predictor of subsequent relapse.


RESULTS
Presence of sub-syndromal depressive symptoms during the first 8 weeks significantly increased the likelihood of depressive relapse (relative risk 4.67, P<0.001). Patients with psychotic features and those with a greater number of previous depressive episodes were more likely to experience sub-syndromal depressive symptoms (RR=2.51, P<0.001 and RR=2.35, P=0.03 respectively).


CONCLUSIONS
These findings help to identify patients at increased risk of affective relapse and suggest that appropriate therapeutic interventions should be considered even when syndromal-level symptoms are absent.
Tohen
Mauricio
M
Lilly Research Laboratories, Indianapolis, IN 46285, USA. m.tohen@lilly.com
Bowden
Charles L
CL
Calabrese
Joseph R
JR
Lin
Daniel
D
Forrester
Tammy D
TD
Sachs
Gary S
GS
Koukopoulos
Athanasios
A
Yatham
Lakshmi
L
Grunze
Heinz
H
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000523:psychology; D003866:Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D018020:Lithium Compounds / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D011379:Prognosis; D012074:Remission Induction; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D018020:Lithium Compounds; D001569:Benzodiazepines; D000077152:Olanzapine