Sir, Prader–Willi syndrome (PWS) is a rare imprinting disorder (15q11–q13) characterized by hypotonia, developmental delay, intellectual disability, and severe hyperphagia with complex behavioral and psychiatric features. Although hypothalamic dysfunction has long been implicated in hyperphagia, recent studies have also demonstrated dopaminergic reward deficits in PWS, suggesting that stimulants enhancing dopaminergic signaling may attenuate pathological eating drives.1 We report an 11-year-old boy with genetically confirmed PWS who displayed severe hyperphagia with frequent food-seeking, poor attention, and emotional outbursts. Cognitive evaluation revealed a Full-Scale IQ of 64 on the Wechsler Intelligence Scale for Children–Revised (WISC-R). At baseline, his height was 146 cm and his weight was 58 kg, corresponding to >97th percentile for age and sex. Despite prior aripiprazole, hyperphagia and impulsivity persisted. Environmental controls (locked food storage, caregiver supervision) and dietary measures were maintained throughout treatment. Long-acting methylphenidate (OROS-MPH) was initiated at 27 mg/day, determined by body-weight considerations. After 1 month, the patient showed marked improvements in attention, emotional regulation, and reduced food-seeking frequency—from 10–15 to 3–4 episodes per day—while the weight remained 58 kg (>97th percentile). At the second-month follow-up, mild recurrence of food preoccupation led to a dose increase to 36 mg/day, resulting in sustained behavioral control. Across 6 months of observation, hyperphagia remained substantially reduced, and the weight decreased to 53 kg (≈95th percentile). The patient also demonstrated improved adherence to previously unsuccessful dietary recommendations after behavioral stabilization. Side-effect monitoring covered vitals, cardiovascular status, sleep, appetite, and mood. Following dose escalation, he developed mild sleep-onset difficulty, which resolved with short-term melatonin supplementation; melatonin was later discontinued without recurrence. Appetite decreased during daytime hours but normalized overall, reflecting therapeutic reduction of excessive drive rather than adverse suppression. No cardiovascular or mood-related side effects occurred. This case contributes to the limited but growing evidence supporting dopaminergic modulation in hyperphagic PWS phenotypes. Prior neuroimaging and epigenetic work indicates dopaminergic hypofunction and hypomethylation in individuals with PWS,1,2 plausibly producing blunted postprandial reward signaling and impaired satiety with compensatory overeating. Methylphenidate enhances dopaminergic tone and can reduce caloric intake by modulating reward pathways linked to feeding behavior.3 Its efficacy has also been described in hypothalamic obesity (e.g., craniopharyngioma), supporting biological plausibility in hyperphagic states.4 While modafinil has been used for excessive daytime sleepiness and lisdexamfetamine reported benefits for hyperphagia in a single case, stimulant monotherapy specifically targeting hyperphagia remains rarely documented.5,6 To our knowledge, this represents the first pediatric case reporting sustained improvement of hyperphagic behavior in PWS with OROS-methylphenidate monotherapy under stable environmental conditions. While emerging pharmacotherapies like VYKAT XR target hyperphagia directly, dopaminergic agents like MPH offer adjunctive potential in comorbid ADHD/impulsivity.7 In our patient, parents reported improved family dynamics and reduced caregiver stress in parallel with behavioral gains. Appetite decreased during daytime but normalized overall, reflecting therapeutic rather than adverse suppression. As a single observation, this finding is not generalizable. Nonetheless, it underscores the interface between neurodevelopmental disorders, psychiatric symptomatology, and reward processing mechanisms. Methylphenidate may thus be considered an adjunctive option in carefully selected children with PWS who present with hyperphagia and attentional or impulse-control difficulties. Further systematic evaluation—such as open-label or crossover studies integrating behavioral metrics and reward-circuit biomarkers—is warranted, with careful nutritional and cardiovascular monitoring in clinical use. Declaration of patient consent Informed consent for publication was obtained from the parents. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Kemal Saruhan (Sun,) studied this question.