Does fluoxetine influence major depression by modifying five-factor personality traits?

Background: Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of depression, though response to them is difficult to predict. The aims of this study were two-fold: (1) to determine the differences in personality profile between patients with major depression and healthy control subjects and (2) to assess the effect of treatment with fluoxetine on personality domain scores and determine whether any of the personality traits can predict the outcome of antidepressant treatment.

Methods: The study included 53 patients with major depression and 53 healthy controls.

Gender differences in association between serotonin transporter gene polymorphism and personality traits.

Since Lesch and colleagues reported an association between anxiety-related traits (Neuroticism) and a functional polymorphism in the serotonin transporter gene regulatory region (5-HTTLPR), there have been several reports on 5-HTTLPR and personality traits with both positive and negative results. The present study was a further attempt to replicate the original findings of Lesch et al. in a population of well-defined normal healthy subjects.

Norepinephrine transporter gene polymorphism is not associated with susceptibility to major depression.

The monoamine neurotransmitters serotonin, norepinephrine and dopamine have been implicated in the pathogenesis of depression, schizophrenia and mood disorders. The mechanism of action of certain antidepressant drugs, particularly the tricyclics and the newly available norepinephrine and serotonin reuptake inhibitors (NSRIs) drugs, venlafaxine and nefazodone, suggest that the norepinephrine transporter, which is a target for these antidepressant drugs, and its malfunction may be involved in major depression. In this association study, we tested the hypothesis that variants of the human norepinephrine transporter (NET) gene confer susceptibility to major depression.