Adjuvant interventions in ADHD: a synthesis of the evidence on nutritional supplements and phytotherapy within an integrated approach

Abstract

Introduction. Attention-deficit/hyperactivity disorder (ADHD) is a common and heterogeneous neurodevelopmental disorder, for which multimodal management (psychoeducation, psychosocial/educational interventions and, when indicated, pharmacotherapy) represents the standard of current clinical practice. In this context, nutritional supplements and phytotherapy are increasingly used as adjunctive interventions, particularly in situations of family preference for options perceived as “natural”, incomplete clinical response, or the presence of specific targets, such as sleep. The aim of this study is to critically synthesize the clinical evidence (meta-analyses, systematic reviews, and randomized clinical trials) regarding the efficacy and safety of the main nutritional supplements and phytotherapeutic agents used as adjuncts in ADHD, integrating the findings into a prudent, personalized, and monitored clinical approach. Materials and methods. A critical, evidence-based narrative synthesis was conducted, focused on sources with robust designs (metaanalyses/ systematic reviews and randomized clinical trials) evaluating omega-3 (EPA/DHA), vitamin D, zinc, iron (particularly in the context of deficiencies), phosphatidylserine, citicoline, L-theanine, melatonin, and phytotherapeutic agents (saffron, Korean red ginseng, Bacopa monnieri). Pediatric populations were analyzed and, where relevant data were available, young adult populations. Results. Overall, the evidence indicates small-to-moderate and heterogeneous effects on core ADHD symptoms, with more evident utility in specific subgroups (for example, in the presence of a documented nutritional deficiency) and for associated targets, particularly sleep. Findings on omega- 3 are variable across meta-analyses; zinc may be associated with modest reductions in total symptom scores, and vitamin D may confer modest benefits as an adjunct to stimulants. Phosphatidylserine shows a modest signal for inattention; citicoline did not demonstrate clear clinical benefit in a randomized pilot study. L-theanine and melatonin are associated with improvements in sleep parameters. Within phytotherapy, saffron showed results comparable to methylphenidate in a pilot study, ginseng demonstrated favorable effects in a randomized study, and Bacopa monnieri has promising, yet unconfirmed, data in the absence of controlled trials. Conclusion. The interventions reviewed should be positioned as adjuncts, not as alternatives to validated interventions. Their responsible integration requires appropriate patient selection (nutritional profile, comorbidities, functional targets), the establishment of realistic expectations, and systematic monitoring of efficacy and safety.