The occurrence of a manic episode before the onset of depression does not predict response to antidepressants in individuals with bipolar disorder, according to a study recently published in the Journal of Affective Disorders.
Researchers hypothesized that manic episode status prior to a major depressive episode may affect response to antidepressants. To examine this, they utilized data from the double-blind, randomized controlled Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) study from 2003. Data from 325 (male, n=140) subjects whose treatment began during an episode of major depression were used, which included those with bipolar I & II, cyclothymia, schizoaffective disorder bipolar subtype, or unspecified bipolar disorder who were at least 18 years old.
Study researchers examined the predictive ability of a manic or mixed episode before the onset of depression for 4 outcomes: 3- and 6-month quantitative change in depressive symptoms, the probability of switching due to antidepressants, and the probability of recovering from depression.
A two-way analysis of variance was used to examine quantitative change in depressive symptoms. Although time showed a significant association with declining depressive symptoms at the 3- and 6-month marks (P<.001), previous episode status did not have the expected predictive power for them (3- and 6-month, P =.987 and .415, respectively).
Logistic regression showed both recovery from depression and switching to mania or hypomania due to antidepressants to have no association with the predictors.
This study was limited by high attrition rates, the possibility of external factors aiding in recovery, and the administration of only 2 types of antidepressants.
The study researchers conclude that “mania and depression may operate separately for those with bipolar disorder, with differential predictors of the onset and offset of mania versus depression. Future directions may consider vulnerability for these episodes separately.”
Mousavi Z, Johnson S, Li D. Does recent mania affect response to antidepressants in bipolar disorder?are-analysis of STEP-BD data [published online April 21, 2018]. J Affect Disord. doi: 10.1016/j.jad.2018.04.097