Psychiatry Research EG

Background Depressive episodes are present in both bipolar disorder (BD) and major depressive disorder (MDD). Do cognitive dysfunction symptoms of depressive episode differ according to the disorder (MDD or BD)? Aim of the work This work aimed to study the cognitive functions among patients with BD (depressive or mixed) and MDD during relapse. Patients and methods This study included 90 patients during relapse diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR) (30 bipolar mixed, 30 bipolar depression, and 30 major depression) and 30 control participants. They were compared in terms of the severity of depression (using the Hamilton Depression Rating Scale), working memory (using the digit span test), processing speed (using the digit symbol test and trail making test A), verbal fluency (using the verbal fluency test), and executive function (using trail making test B). Results The scores of BD patients were significantly worse than those of MDD patients in digit span tests (forward and backward), digit symbol test, verbal fluency test, and trail making tests (A and B). No significant difference was found between bipolar depression patients and bipolar mixed patients in the patterns of cognitive dysfunctions and the severity of cognitive dysfunctions. Conclusion Bipolar patients experience significantly greater impairment than major depression patients. Other differentiators between the two disorders were that BD have lower age of illness onset, higher number of previous episodes, higher numbers of previous hospitalizations, and greater presence of psychotic features than MDD.