Reduced Methylphenidate Use Following Dietary Modification in Adult ADHD: A Case Report

Alan Tran DO¹ and Binh Pham DO MPH MS^2,

¹Neighborhood Healthcare, Menifee, CA, USA

²Southwest Healthcare Medical Education Consortium, Temecula, CA, USA

Cite this paper:
Alan Tran DO and Binh Pham DO MPH MS. Reduced Methylphenidate Use Following Dietary Modification in Adult ADHD: A Case Report. Research in Psychology and Behavioral Sciences. 2026; 14(2):28-31. doi: 10.12691/rpbs-14-2-1

Abstract

Attention-deficit/hyperactivity disorder (ADHD) frequently persists into adulthood and is commonly managed with stimulant medications. Interest in nutritional and lifestyle interventions as potential adjunctive strategies has increased, although evidence in adults remains limited. We describe a 24-year-old man with ADHD who presented with impaired concentration and executive functioning affecting academic performance. Methylphenidate immediate release 5 mg twice daily improved focus and assignment completion and was continued without dose escalation. Over subsequent follow-up, stimulant use became less consistent. After counseling regarding diet, physical activity, and alcohol use, the patient adopted a low-carbohydrate, high-fat dietary pattern and incorporated regular walking. At later follow-up, he reported improved concentration and was using methylphenidate only occasionally as needed. He had also completed an associate degree and experienced a 25.4-pound weight reduction. Nutritional ketosis was not biochemically confirmed, and standardized serial ADHD measures were unavailable. Because reduced stimulant use had begun before the dietary intervention was clearly documented and several lifestyle changes occurred concurrently, a causal relationship cannot be established. This hypothesis-generating case describes a longitudinal association between dietary and lifestyle modification, reduced stimulant utilization, and preserved functional progress in an adult with ADHD, but it does not support generalization to routine clinical practice without prospective confirmation.

Keywords:
attention-deficit/hyperactivity disorder ADHD methylphenidate ketogenic diet low-carbohydrate diet nutrition

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