Endocrine Abstracts

Introduction: Anger is an emotional state of feelings varying from mild irritation to intense rage, whereas aggression implies externalizing angry emotions through destructive/ punitive behavior towards other persons/objects. Although research on the relationship between testosterone and aggression is inconclusive, the WPATH SOC 7 guidelines have warned for an increase in aggression in transgender men (TM) taking testosterone treatment.

Aims:

1. As aggression is initiated by angry feelings, we aim to assess whether anger proneness increases in TM and decreases in transgender women (TW) after initiation of gender affirming treatment.

2. To identify predictors for an increase (TM) or decrease (TW) of anger proneness.

Methods: This prospective cohort study is part of the European Network for the Investigation of Gender Incongruence (ENIGI). Anger was prospectively assessed in 440 TM and 468 TW by STAXI-2 (State-Trait Anger Expression Inventory 2) questionnaire during three year follow-up, starting at initiation of hormone treatment. Upon first clinical contact, participants filled in psychological questionnaires (Kreukels, 2012). Data were analyzed cross-sectionally and prospectively.

Results: Baseline STAXI-2 scores were comparable in TW and TM (15.0 (15.0–16.8) and 15.0 (15.0–16.0), P=0.777). TM showed a small increase in total STAXI-2 scores after three months, compared to baseline (+0.90, 95%CI 0.037–1.75, P=0.041), decreasing after one year (−1.296, 95% CI −2.15 to −0.44) to scores comparable to baseline (P=0.235), after which scores remained stable. At three months, there was no correlation between STAXI-2 scores and serum total testosterone or oestradiol levels, nor an association with co-existent psychiatric morbidities assessed by MINI plus and SCL-90R. At three months of testosterone treatment (cross-sectionally), TM reporting stronger negative affect (PANAS) experienced more anger proneness (ρ=0.113, P=0.003). Over 36 months in TM (prospectively), anger proneness was positively correlated to negative affect (ρ=0.415, P<0.001) and SCL-factors somatization (ρ=0.075, P=0.033), paranoid ideation/psychoticism (ρ=0.101, P=0.004), depression (ρ=0.082, P=0.019) and interpersonal sensitivity (ρ=0.119, P=0.001). In TW, STAXI-2 scores did not change over time (P=0.952). At three months, there was no correlation between STAXI-2 scores and serum testosterone.

Conclusions: Evidence from a prospective study shows no association between anger proneness and exogenous testosterone administration in TM. TM with psychological/ psychiatric difficulties before gender affirming therapy are more likely to show a (temporarily) increase in anger proneness.