Insomnia often goes untreated despite adverse mood and neurobehavioral effects.1 A key objective in DSM-5 is improved management of sleep disorders comorbid with psychiatric conditions.1 Circadian rhythm sleep disorder (CRSD) occurs in 70% of patients with attention deficit/hyperactivity disorder (ADHD).2 We present a case of severe CRSD, delayed sleep phase type in a patient with ADHD, which was undetected before actigraphy, to increase clinicians’ awareness of this common, albeit neglected, condition. We also discuss validated actigraphic sleep assessment devices that may help detect this condition. Actigraphy’s advantages over polysomnography have led to increased use of actigraphy in research and sleep clinic settings.3 Actigraphic smartphone applications and commercial accelerometers (Sleep Cycle®, UP Wristband®, Sleep Manager Pro®, The One™FitBitz) are available to the general public…