The efficacy of 2 different dosages of methylphenidate in treating adults with attention-deficit hyperactivity disorder.

OBJECTIVE

To evaluate the efficacy of methylphenidate in treating adults with attention-deficit hyperactivity disorder (ADHD), using subjective (self-report) and objective (computerized test) measures.

METHOD

This double-blind crossover trial of placebo vs methylphenidate included subjects with childhood and current ADHD symptoms, IQs above 80, no other psychiatric condition explaining their difficulties or requiring other treatment, and no substance abuse in the previous 6 months. We administered 10 mg 3 times daily of medication (that is, placebo or methylphenidate) for 2 weeks. On the final day, subjects completed self-report measures and were tested on computerized tests. We then increased dosage to 15 mg 3 times daily for 2 weeks and administered a complete reassessment on the final day. Following a 1-week washout, we repeated this process on the second medication (that is, placebo or methylphenidate).

RESULTS

Thirty adults with ADHD participated. Self-report measures and computerized tests showed significant improvements in ADHD symptoms on methylphenidate, compared with placebo. Other psychiatric symptoms (notably, anxiety and depression) were alleviated with methylphenidate. There was no significant difference between the 2 dosages of methylphenidate.

CONCLUSION

Methylphenidate is effective in improving ADHD symptoms in adults with ADHD, is well tolerated, and has minimal side effects.