Effects of stimulant medication on divergent and convergent thinking tasks related to creativity in adults with attention-deficit hyperactivity disorder

Rationale Common pharmacological treatments for attention-deficit hyperactivity disorder (ADHD) are central nervous system stimulants acting as norepinephrine-dopamine reuptake inhibitors. The noradrenergic and dopaminergic systems have been shown to impact performance on tasks assessing creativity. Some previous studies suggest higher performance on creativity tasks in ADHD. Stimulant medication has been shown to differentially impact creativity in those without ADHD. However, the full range of effects of stimulant medication on creativity in those with ADHD is not known. Objectives This study examined the effects of stimulants on convergent and divergent tasks associated with creativity in adults with ADHD. Method Seventeen adults diagnosed with ADHD who were prescribed stimulant medication attended two counterbalanced sessions: one after taking their prescribed stimulant dose and one after the dose was withheld. Participants completed convergent problem-solving (anagrams, Compound Remote Associates) and divergent generative (letter/semantic fluency, Torrance Test for Creative Thinking (TTCT)-Verbal) tasks. Results There was a significant increase in words generated on the semantic fluency task for the stimulant session. Additionally, significant increases were found in the stimulant session for originality, flexibility, and fluency scores on the TTCT. Stimulant medication did not have an effect on any of the problem-solving tasks. Conclusions Stimulant medication enhanced verbal fluency in adults with ADHD but had no effect on convergent abilities. Furthermore, stimulants enhanced fluency, flexibility, and originality scores on the TTCT. Therefore, stimulants appear to have positive effects on divergent task performance in adults with ADHD, but not convergent tasks. This finding warrants further studies into the specific roles of norepinephrine and dopamine in this effect.