Is Low IQ Associated with Depression? Cognitive Impairment in the Context of Major Depressive Disorder in Two Longitudinal Birth Cohort Studies

Few longitudinal studies have systematically examined the temporal ordering of cognitive deficits and Major Depressive Disorder (MDD). Using two longitudinal cohort studies, we found that IQ deficits were neither an antecedent nor an enduring consequence of MDD, except when MDD was accompanied by other comorbid psychiatric conditions.