Efficacy of stimulants for cognitive enhancement in non-attention deficit hyperactivity disorder youth: a systematic review

Background and Aims Increasing prescription stimulant abuse among youth without diagnoses of attention deficit hyperactivity disorder (ADHD) is of concern. The most frequently cited motive for abuse is improved academic achievement via neurocognitive enhancement. Our aim in reviewing the literature was to identify neurocognitive effects of prescription stimulants in non-ADHD youth. Methods A systematic review was conducted for youth aged 12-25 years using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Fourteen papers were included. Results Modafinil appears to improve reaction time (P <= 0.04), logical reasoning (P <= 0.05) and problem-solving. Methylphenidate appears to improve performance in novel tasks and attention-based tasks (P <= 0.05), and reduces planning latency in more complex tasks (P <= 0.05). Amphetamine has been shown to improve consolidation of information (0.02 >= P <= 0.05), leading to improved recall. Across all three types of prescription stimulants, research shows improved attention with lack of consensus on whether these improvements are limited to simple versus complex tasks in varying youth populations. Conclusions The heterogeneity of the non-attention deficit hyperactivity disorder youth population, the variation in cognitive task characteristics and lack of replication of studies makes assessing the potential global neurocognitive benefits of stimulants among non-attention deficit hyperactivity disorder youth difficult; however, some youth may derive benefit in specific cognitive domains.