Stimulant shortage in children with ADHD: greater vulnerability among those with comorbidity

The aim of this study was to examine stimulant access difficulties among school-aged children with attention-deficit/hyperactivity disorder (ADHD) in Turkey, family strategies to obtain medications, and access-related medication changes, and to evaluate their associations with irritability, emotional, behavioral, social, academic, and sleep difficulties by psychiatric comorbidity.

A cross-sectional study was conducted with 149 children aged 6-16 years diagnosed with ADHD and treated with methylphenidate-based stimulants, the only stimulant medications available for pediatric ADHD in Turkey, for at least three months. Data were collected using a sociodemographic form, the Medication Shortage Experience Assessment Form, and standardized parent-report scales, including the DSM-5 Level 2 Irritability Scale, Strengths and Difficulties Questionnaire (SDQ), and Sleep Disturbance Scale for Children (SDSC). Group comparisons were performed according to medication change and comorbidity status, followed by multivariable Generalized Linear Models (GZLM) to evaluate interaction effects between these variables.

Nearly all parents (97.3%) reported difficulties, and 55.7% required medication switching due to shortages. Medication changes were associated with significantly greater perceived impacts on physical and mental health (77.1% vs. 42.4%, p < .001) and on academic and social functioning (69.9% vs. 51.5%, p = .022). In children who underwent medication changes, those with psychiatric comorbidities showed significantly higher irritability, emotional symptoms, conduct problems, peer relationship issues, and total SDQ difficulty scores compared with non-comorbid peers. GZLM interaction analyses formally confirmed these findings, showing that the combination of medication change and psychiatric comorbidity significantly predicted higher irritability (B = 2.65, p = .017), sleep arousal disorders (B = 1.12, p = .028), and total sleep disturbances (B = 9.56, p = .043). Notably, interaction coefficients were positive across nearly all psychometric scales, indicating a synergistic worsening of symptoms, except for prosocial behavior, which showed an expected negative coefficient.

Stimulant shortage is highly prevalent and disrupt treatment continuity in children with ADHD in Turkey. Those with psychiatric comorbidities appear particularly sensitive to medication changes, with our findings formally demonstrating a synergistic interaction that amplifies clinical vulnerability. These results highlight the need for coordinated supply systems and targeted psychosocial support to mitigate the emotional and functional consequences of stimulant unavailability.