Self-rated aggression related to serum testosterone and platelet MAO activity in female patients with the fibromyalgia syndrome.

To investigate self-rated aggression in relation to platelet MAO activity and serum testosterone in patients with fibromyalgia syndrome (FMS), we administered the Aggression Questionnaire - Revised Swedish Version (AQ-RSV) to 30 female patients with FMS. After correction for age, significant positive correlations were seen between serum testosterone concentrations and the AQ-RSV scores for Verbal Aggression (r = 0.36, p < 0.05) and Anger (r = 0.37, p < 0.05), whereas the platelet MAO activity was negatively correlated with the score for Verbal Aggression (r = -0.44, p < 0.05). Our results suggest that aggression and irritability in female FMS patients might be increased by elevated testosterone concentrations in combination with reduced capacity of the serotonergic system as reflected by low platelet MAO activity.