Adult ADHD is associated with delayed circadian rhythmicity and analogous sleep characteristics, which are typical of a delayed sleep phase disorder. Stimulants induce delay of circadian rhythmicity.

In circadian rhythm sleep-wake disorders precision medicine is less developed than in other medical disciplines mainly because homeostatic sleep and circadian timing have a very complex phenotype with multiple genetic regulation mechanisms. However, biomarkers, phenotyping and psychosocial characteristics are increasingly used. Devices for polysomnography, actigraphy and sleep-tracking applications in mobile phones and other consumer devices with eHealth technologies are increasingly used. Also sleep-related questionnaires and the assessment of co-morbidities influencing sleep in circadian rhythm sleep-wake disorders are major contributors to precision sleep medicine. To further strengthen the (pharmaco-)genetic and biomarker pillar, technology needs to be evolved further. Routinely measuring treatment results using patient-reported outcome measures and clinical neurophysiological instruments will boost precision sleep medicine.

In this observational cross-sectional study, 49 subjects were assessed for sleep disorders and for ADHD symptoms. Thirty-six received an ADHD diagnosis (29: combined type (ADHD-C); 7: inattentive type). An RLS and RLS symptoms prevalence of 34.5% was found, with a higher prevalence rate in the ADHD-C subgroup, although not significantly (p = 0.066). RLS symptoms were correlated with particularly hyperactivity-impulsivity (ρ = 0.742; p: 0.000). ADHD patients with positive RLS scores reported higher scores on the ADHD-Rating scale compared with patients with negative RLS scores (Z: -2.968, p = 0.003), mainly due to higher hyperactivity-impulsivity scores (Z: -3.145; p = 0.002). Our findings show that clinicians need to be aware of RLS among adult ADHD patients, particularly those with severe hyperactivity-impulsivity symptoms.

To explore the effect of methylphenidate on sleep and circadian rhythmicity, actigraphic sleep-wake rhythm, Dim Light Melatonin Onset (DLMO), Phase Angle Difference (PAD; time between DLMO and mid-sleep) and attention-deficit/hyperactivity disorder (ADHD) Rating Scale were assessed before and after 4-week treatment with methylphenidate in 10 adults with ADHD. During methylphenidate treatment DLMO did not change, while melatonin concentration at 23.00 hours increased. Phase advance type (PAD > 6 h) before treatment was associated with a greater treatment-related reduction in attention symptoms. These results suggest that PAD > 6 h might have a predictive value for the effect of methylphenidate.

No abstract