G. Leonard Burns

Objective The internal (structural) and external validity of a self‐report measure of cognitive disengagement syndrome (CDS, formerly sluggish cognitive tempo) relative to a self‐report measure of attention‐deficit/hyperactivity disorder‐inattention (ADHD‐IN) was evaluated with adults from university outpatient psychiatric clinics in Turkey. Methods A total of 274 outpatients (75.9% women; ages 18–64 years; M age = 31.06; SD age = 10.84; 50.4% anxiety disorders; 41.6% depressive disorders; 2.9% ADHD; 1.5% sleep disorders; 0.7% eating disorders; 2.9% no mental disorder) completed self‐report measures of CDS, ADHD‐IN, ADHD‐hyperactivity/impulsivity (HI), sleep problems, depression, and stress. Results All 15 CDS symptoms measured by the Adult Concentration Inventory (ACI) showed convergent (moderate to high loadings on the CDS factor) and discriminant (loading close to zero on the ADHD‐IN factor) validity. CDS also showed stronger first‐order and unique associations than ADHD‐IN with sleep problems, depression, anxiety, and stress, whereas ADHD‐IN showed stronger first‐order and unique associations than CDS with ADHD‐HI. Conclusion This is the first study to provide support for the scores from this 15 item self‐report measure of CDS by the ACI in a clinical sample of adults, with findings consistent with previous studies examining parent and teacher rating scale measures with the same 15 CDS symptoms. These findings provide additional support for usefulness of these 15 CDS symptoms as measured by the ACI to study CDS across various cultures.