Psychometric validation of Barkley's Adult Sluggish Cognitive Tempo (SCT) Ratings Scale -Turkish version and distinguishing SCT from attention deficit-hyperactivity disorder (ADHD) among Turkish adults.

Background & Aims: SCT is characterized by sluggishness, daydreaming, lethargy/ apathy, slowed behavior/thinking, and mental confusion. For a long time these symptoms were thought to be a part of ADHD but then studies revealed that SCT is a different phenomenon in some cultures. In this study. we aimed to examine the validity and reliability of Barkley's Adult SCT Ratings Scale, and to determine if SCT is an independent factor from ADHD in Turkish adults like in other cultures.

Methods: 274 Medical School students/trainees enrolled the study (Age: 18-35, 70.4 % female). Data was collected via an online survey including SCT and ADHD rating scales.

Results: Exploratory factor analysis demonstrated that the scale consisted of two factors: Daydreaming and Sluggishness.The model demonstrated a good-fit (χ = 43.642, p = 0.001; χ/df = 2.425, GFI = 0.962,RMSEA = 0.072). As expected, there were positive and significant associations between SCT total, Daydreaming, Sluggishness, and ADHD-Inattention scores (r = 0.645, 0.664, 0.382; respectively), but all SCT items loaded within SCT factors and distinquished from ADHD factors. Cronbach's alpha values were: 0.87 for SCT-total, 0.87 for Daydreaming; 0.79 for Sluggishness.

Conclusion & Implications: Our study provides a valid and reliable SCT screening tool for Turkish adults and increases our confidence in the transcultural generalizability of SCT.