Selective alteration of personality in response to noradrenergic and serotonergic antidepressant medication in depressed sample: evidence of non-specificity

Recent investigations suggest that serotonergic mechanisms modulate dimensi ons of personality, in particular decreases in Anger-Hostility and increase s in Affiliation. None of these studies, however, demonstrated a specific s erotonergic effect on personality, as other neurotransmitter systems have n ot been assessed for their impact on these personality dimensions. In this study, 76 depressed outpatients were treated with either the noradrenergic antidepressant desipramine (n = 38) or a selective serotonin re-uptake inhi bitor (paroxetine or sertraline) (n = 38) over a period of 8-14 weeks. Pers onality scores were measured pre- and post-treatment using the revised NEO Personality Inventory, which measures five basic dimensions of personality, with subscales assessing Anger-Hostility and Affiliation (Gregariousness). There was a significant decrease in Neuroticism and Anger-Hostility, and a significant increase in Extraversion and Gregariousness following antidepr essant treatment. Although changes in neuroticism and extraversion were sig nificantly correlated with change in depression severity, Anger-Hostility a nd Gregariousness personality scores were not. Therefore, changes in these personality traits were not attributable to a non-specific effect of medica tion on changes in depression severity. There were no significant differenc es in personality change scores between the antidepressant treatment groups . Thus, while antidepressants may have a direct effect on neurochemical pat hways relevant to personality, independent of changes in depression severit y, these effects cannot be directly or specifically attributed to a seroton ergic mechanism. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved .