This recently updated Cochrane Intervention Review examined the efficacy and safety of amphetamines for adults with ADHD.
The review included 19 studies with 2521 participants, most of whom were middle-aged (35.3 years), Caucasian males (57.2%) with a combined type of ADHD (78.8%). Eighteen studies were conducted in the USA and one study was conducted in both Canada and the USA. Sixteen studies were funded by pharmaceutical companies, one study was publicly funded, and two studies did not report their funding sources.
The studies examined three types of amphetamines: dexamphetamine (10.2 mg/d to 21.8 mg/d), lisdexamfetamine (30 mg/d to 70 mg/d), and mixed amphetamine salts (12.5 mg/d to 80 mg/d). All studies were placebo controlled and three also included an active comparator: guanfacine, modafinil or paroxetine.
The review authors found low- to very low-quality evidence that amphetamines reduce the severity of ADHD symptoms in the short term, but do not improve retention to treatment and are associated with higher attrition due to adverse events. There were no differences in effectiveness between amphetamines and guafacine, modafinil, or paroxetine. No study was at low risk of bias overall, namely because it was possible for participants to know which treatments they were taking. In addition, results were imprecise for many outcomes because the number of studies and included participants was low. The studies also had problems in their design and most were of short duration (mean study length = 5.3 weeks).
Read the full review here.