Neural correlates of antidepressant-related sexual dysfunction: a placebo-controlled fMRI study on healthy males under subchronic paroxetine and bupropion

Neuropsychopharmacology. 2011 Aug;36(9):1837-47. doi: 10.1038/npp.2011.66. Epub 2011 May 4.

Abstract

Sexual dysfunction is a common side effect of selective serotonin reuptake inhibitors (SSRIs) like paroxetine in the treatment of depression, imposing a considerable risk on medication adherence and hence therapeutic success. Bupropion, a norepinephrine and dopamine reuptake inhibitor, is recommended as an alternative treatment without adverse effects concerning sexual arousal and libido. We investigated the neural bases of paroxetine-related subjective sexual dysfunction when compared with bupropion and placebo. We scanned 18 healthy, heterosexual males in a randomized, double-blind, within-subject design while watching video clips of erotic and nonerotic content under steady-state conditions after taking 20 mg of paroxetine, 150 mg of bupropion, and placebo for 7 days each. Under paroxetine, ratings of subjective sexual dysfunction increased compared with placebo or bupropion. Activation along the anterior cingulate cortex (ACC), including subgenual, pregenual, and midcingulate cortices, in the ventral striatum and midbrain was decreased when compared with placebo. In contrast, bupropion let subjective ratings and ACC activations unchanged and increased activity of brain regions including posterior midcingulate cortex, mediodorsal thalamus, and extended amygdala relative to placebo and paroxetine. Brain regions that have been related to the processing of motivational (ventral striatum), emotional, and autonomic components of erotic stimulation (anterior cingulate) in previous studies showed reduced responsiveness under paroxetine in our study. Drug effects on these regions may be part of the mechanism underlying SSRI-related sexual dysfunction. Increased activation under bupropion may point to an opposite effect that may relate to the lack of impaired sexual functioning.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Antidepressive Agents / adverse effects*
  • Antidepressive Agents / therapeutic use
  • Bupropion / administration & dosage*
  • Dopamine Uptake Inhibitors / administration & dosage
  • Double-Blind Method
  • Humans
  • Limbic System / drug effects
  • Limbic System / pathology
  • Limbic System / physiopathology
  • Magnetic Resonance Imaging
  • Male
  • Neurons / drug effects*
  • Neurons / pathology
  • Neurons / physiology
  • Paroxetine / adverse effects*
  • Selective Serotonin Reuptake Inhibitors / adverse effects
  • Sexual Dysfunction, Physiological / chemically induced*
  • Sexual Dysfunction, Physiological / drug therapy*
  • Sexual Dysfunction, Physiological / physiopathology
  • Young Adult

Substances

  • Antidepressive Agents
  • Dopamine Uptake Inhibitors
  • Serotonin Uptake Inhibitors
  • Bupropion
  • Paroxetine