Cognitive Disengagement Syndrome: History, Assessment, and Diagnostic Implications

Cognitive Disengagement Syndrome (CDS)—formerly referred to as Sluggish Cognitive Tempo (SCT)—is an empirically supported clinical construct characterized by excessive daydreaming, mental fogginess, staring, slowed thinking, hypoactivity, and fatigue. Historically conceptualized as a feature or subtype of ADHD, contemporary research confirms that CDS is empirically distinct from ADHD inattention, demonstrating stronger associations with internalizing symptoms, social withdrawal, and subjective cognitive disconnection.

Although CDS is not currently a formal diagnosis in the DSM-5-TR, a growing body of literature highlights its clinical significance and independent functional impairment. Assessing CDS requires a comprehensive, multi-informant evaluation to differentiate it from ADHD, mood and anxiety disorders, sleep disturbances, trauma, and medical conditions. Understanding and evaluating CDS allows clinicians to provide targeted accommodations and functional supports for individuals experiencing chronic cognitive fog and disengagement, validating difficulties that have often been misattributed to poor motivation or personal failure.