Effects of medications on sleep quality, insomnia, and circadian rhythm in adults with ADHD: A pragmatic longitudinal study.

OBJECTIVE

Sleep disturbances are common in adults with attention-deficit/hyperactivity disorder (ADHD), yet little is known about how pharmacotherapy and psychiatric comorbidities influence sleep over time in this population. This study examines longitudinal associations between medication use and sleep outcomes in adults with ADHD.

METHODS

A prospective observational study was conducted with 149 adults diagnosed with ADHD attending a specialist clinic in Ireland. Participants were assessed at five time points over 18 months. Sleep outcomes were measured using the Pittsburgh Sleep Quality Index (PSQI), Sleep Disorders Symptoms Checklist (SDS-CL-17), for measurement of insomnia, circadian rhythm sleep-wake disorder, (CRSWD), and chronotype. Mixed-effects models evaluated the impact of ADHD medications (stimulants and non-stimulants), antidepressants, antipsychotics, demographic variables, co-occurring psychiatric disorders, and Autism Spectrum Disorder (ASD) traits on sleep quality, insomnia, CRSWD, and chronotype.

RESULTS

Stimulant use was significantly associated with improved sleep quality and reduced odds of insomnia. Non-stimulant medications (atomoxetine) were linked to lower odds of insomnia and CRSWD. Antidepressant use significantly associated with increased insomnia risk. Poorer sleep quality was also associated with female sex, higher BMI, and greater psychiatric comorbidity. ASD traits did not independently predict any sleep outcome. Chronotype was not associated with any clinical or demographic factor.

CONCLUSIONS

Pharmacological treatment, particularly with stimulants and non-stimulants, may stabilize sleep in adults with ADHD. Coexistence of psychiatric disorders and antidepressant use negatively affect sleep. ASD traits did not show independent effects on sleep when controlling for other factors. Comprehensive, individualized care is essential in this population.