Unexpected restrictive eating in attention-deficit/hyperactivity disorder: resolution following methylphenidate reintroduction

Introduction

Stimulant medications such as methylphenidate, widely used in the treatment of attention-deficit/hyperactivity disorder (ADHD), are associated with appetite suppression and weight loss through dopaminergic pathways that influence reward and eating behavior [1]. Drug holidays are often implemented to mitigate these effects, although the behavioral consequences of stimulant discontinuation remain unclear [2]. ADHD is also associated with dysregulated eating behaviors and increased risk of eating disorders [3]. There is limited evidence on the emergence of restrictive eating behaviors following stimulant discontinuation. We present a case of a 14-year-old male with ADHD who developed restrictive eating behaviors during a methylphenidate drug holiday. The patient reported caloric restriction, excessive exercise, daily weighing, and significant weight loss. This case highlights a possible temporal association between stimulant discontinuation and the emergence of disordered eating behaviors, emphasizing the need for clinical awareness during medication-free periods.

Case Presentation

A 14-year-old male diagnosed with ADHD at age 9 had been treated with methylphenidate in various formulations. While receiving long-acting methylphenidate 27 mg and short-acting methylphenidate 10 mg, treatment was discontinued during a drug holiday from June to September. The patient presented in September with a two-month history of caloric restriction, daily weighing, excessive exercise, and weight loss of approximately 7 kg over two months. There was no prior history of eating disorder symptoms, and these symptoms appeared during the time without medication. Methylphenidate treatment was subsequently reinitiated. Fluoxetine was also prescribed for restrictive eating behaviors; however, the patient was non-adherent to this medication. Despite this, a marked improvement in eating behaviors was observed after methylphenidate reintroduction.

Discussion

This case suggests a temporal association between stimulant discontinuation and the onset of restrictive eating behaviors. Methylphenidate suppresses appetite, and discontinuation may lead to rebound appetite changes and altered reward processing. These changes, combined with weight fluctuations, may heighten body awareness and susceptibility to disordered eating, with ADHD-related impulsivity and emotional dysregulation potentially exacerbating this vulnerability. These findings may have important clinical implications for monitoring eating behaviors during medication transitions in adolescents with ADHD. To our knowledge, this phenomenon has not been systematically reported, highlighting a gap in the literature.

Conclusion This case suggests that restrictive eating behaviors may emerge during methylphenidate drug holidays and demonstrate a reversible course following treatment reinitiation. The temporal pattern observed highlights a potential role of stimulant discontinuation in altering reward-related eating regulation and increasing vulnerability to disordered eating behaviors in adolescents with ADHD. Clinicians should be aware that drug holidays, although commonly used to mitigate side effects, may carry underrecognized behavioral risks, particularly in relation to eating patterns. Careful monitoring of weight, eating behaviors, and body-related perceptions during medication-free periods is warranted. Further systematic studies are needed to clarify the mechanisms underlying this association and to identify patients at increased risk.

References

1. . Davis, C., Fattore, L., Kaplan, A. S., Carter, J. C., Levitan, R. D., & Kennedy, J. L. (2012). The suppression of appetite and food consumption by methylphenidate: the moderating effects of gender and weight status in healthy adults. The international journal of neuropsychopharmacology, 15(2), 181–187. https://doi.org/10.1017/S1461145711001039
2. . Ibrahim K, Donyai P. Drug holidays from ADHD medication: international experience over the past four decades. J Atten Disord. 2015;19(7):551–568. https://doi.org/10.1177/1087054714548035
3. . Reinblatt S. P. (2015). Are Eating Disorders Related to Attention Deficit/Hyperactivity Disorder?. Current treatment options in psychiatry, 2(4), 402–412. https://doi.org/10.1007/s40501-015-0060-7