Improvement of attention deficit/hyperactivity disorder (ADHD) in three adult men during testosterone treatment: a case series 

BACKGROUND: Attention deficit/hyperactivity disorder (ADHD) entails inattention, impulsivity, and restlessness at a disabling level. The pharmacological treatment of ADHD rests on the use of centrally acting stimulants, such as methylphenidate and D-amphetamine. In some patients, these drugs cause side effects that preclude their use. CASE PRESENTATION: We present three adult male, Caucasian, ADHD patients (24, 37, and 43 years old) whose ADHD symptoms improved during treatment with testosterone. The first patient experienced loss of libido during treatment with methylphenidate; for this, he was offered a trial of testosterone. Unexpectedly, his ADHD symptoms improved with testosterone treatment, and this effect continued with testosterone as monotherapy. The two other patients, who also had side effects from centrally acting stimulants, received testosterone monotherapy with similar results. The effect has now continued for 4.5–5 years at the same doses: 10–60 mg testosterone/day, administered as a skin gel. Prior to testosterone treatment, the patients had serum levels of testosterone in the low–normal range: 12–16 nmol/L (age-specific reference range: 10.4–32.6 nmol/L). The testosterone/sex hormone-binding globulin ratio was low in two patients (0.32 and 0.34; age-specific reference range: 0.38–1.1), suggesting low free serum levels of testosterone. Serum testosterone levels and testosterone/sex hormone-binding globulin ratios increased with testosterone treatment in all patients, but remained within reference values. CONCLUSION: These cases suggest that a moderately reduced serum level of free testosterone may contribute to the ADHD symptoms of some adult male ADHD patients, and that testosterone treatment may be of value for these patients.