Objective: In boys, constitutional delay of growth and puberty (CDGP) has been associated with diverse negative psychosocial effects. Albeit alleviating distress is one of the main reasons for inducing pubertal development, the impact of puberty-promoting treatment on psychosocial wellbeing is under-researched. Our objective was to investigate the impact of puberty-promoting therapies on the behavioural patterns as defined by the temperament characteristics emotionality, activity, and sociability (EAS) in boys with CDGP.

Design: The study is a randomized, controlled, open-label trial.

Patients: Thirty boys were randomized to receive either aromatase inhibitor letrozole (2.5 mg/day) (n = 15) or intramuscular testosterone (1 mg/kg/every 4 weeks) (n = 15) for 6 months and followed up to 12 months. To compare our results with healthy peers, an age- and postal-code matched, and a national reference population were collected.

Measurements: Temperament characteristics were evaluated with a standardized and validated questionnaire at 0-, 6-, and 12-month visits.

Results: In comparison to local peers, boys with CDGP were more withdrawn (p = 0.02) and experienced less anger (p = 0.02) and fear (p = 0.02). Compared to both local and national controls, there was a significant difference in emotionality, CDGP boys being less negatively emotional than peers (p = 0.04). Sociability was higher in the Lz-group in comparison to the T-group both after the 6-month treatment period (-0.48, 95% CI: 0.89; -0.08, p = 0.019) and at 12-month follow-up (-0.72, CI: 95%, -1.12; -0.32, p = 0.001).

Conclusion: Overall, boys with CDGP exhibited a generally docile temperament. The administration of puberty-promoting treatments did not result in any adverse psychosocial effects on the temperament characteristics assessed.