Does testosterone treatment increase anger expression in a population of transgender men?

Background: The acquisition of phenotypic male features in transmen with gender dysphoria requires testosteronetreatment. The suppression of menses is 1 of the most desired effects. The relation between testosteronelevels and human aggressive behavior has been described. However, the effects of testosterone on anger expressionhave been poorly investigated in trans-persons.Aim: To assess the effects of testosterone treatment on anger expression in transmen using a validated self-reportquestionnaire (Spielberger’s State-Trait Anger Expression Inventorye2 [STAXI-2]).Methods: 52 transmen diagnosed with gender dysphoria were evaluated before (T0) and at least 7 months after(T1) initiation of continuous gender-affirming testosterone treatment. Sociodemographic characteristics,anthropometric parameters, diagnosis of psychiatric disorders, current psychopharmacologic treatments, and lifeevents were investigated at T0.Outcomes: STAXI-2 scores, serum testosterone, and estradiol levels at T0 and T1 were compared.Results: Most of the sample (61.5%, n ¼ 32) had no Axis I or II comorbidity. All subjects at T1 achievedsignificantly higher serum testosterone levels (5.67 ± 3.88 ng/mL), whereas no significant difference in estradiol levelswas observed from T0 to T1. At T1 only 46.2% (n ¼ 24) of the sample achieved iatrogenic amenorrhea, whereasmost of the sample had persistent regular bleedings. A significant increase in STAXI anger expression and angercontrol scores from T0 to T1 was recorded. Patients with persistent bleedings and Axis I disorders seemed to havehigher odds of expressing anger. However, circulating testosterone levels at T1 did not influence anger expression.Clinical Implications: Interestingly, despite the increase of anger expression scores, during continuous testosteronetreatment, there were no reports of aggressive behavior, self-harm, or psychiatric hospitalization.Strengths and Limitations: A limitation to this study is that although the STAXI-2 is a well-validatedinstrument measuring anger expression, it is a self-report psychometric measure.Conclusion: This study demonstrates that during 7 months of continuous gender-affirming hormonal treatment,anger expression and anger arousal control increased in transmen. Persistence of menstrual bleedings and Axis Idisorders, but not circulating testosterone levels, were predictive of the increase in anger expression score.Continuous psychological support to transmen during gender-affirming hormonal treatment was useful to preventangry behaviors and decrease the level of dysphoria.