Objective: The aim of this paper is to determine the efficacy of dexamphetamine in adult attention deficit hyperactivity disorder (ADHD) in a naturalistic setting.
Method: A randomised, double-blind, placebo-controlled study of dexamphetamine was conducted by two psychiatrists in private practice who saw a total of 68 consecutive referrals of patients thought to have ADHD by their referring general practitioners. Patients were admitted to the study if their current level of ADHD symptoms satisfied DSM-IV criteria (modified for use in adults), and were not currently comorbid for major mood disturbance or substance abuse. Response to medication was assessed by repeated administration of these modified DSM-IV criteria, self- and relatives' rating, as well as clinician rating using the Clinical Global Impressions Scale. More general outcome measures included the Brief Symptom Inventory and a patient satisfaction questionnaire. Medication side effects were recorded, including monitoring blood pressure and weight change. Urinalysis monitored concurrent substance usage and compliance.
Results: Dexamphetamine had a significant therapeutic response exceeding the placebo response (p = 0.045). The response was similar in both genders and across the age range. It was detected by patients, their relatives and the two clinicians. The only significant side effect was weight loss. One patient on dexamphetamine discontinued the trial because of an event possibly related to the medication.
Conclusions: In the short term, dexamphetamine appears to be efficacious in treating adult ADHD. As this is the first study in the literature, the result requires replication. Given that stimulant medication use in adult ADHD appears to be long-term, studies of long-term efficacy need to be carried out.