Psychometric Properties of the Korean Version of THINC-integrated Tool (THINC-it-K): A Tool for Screening Assessment of Cognitive Function in Patients with Major Depressive Disorder.

OBJECTIVE

: The present study was performed to investigate the validity and reliability of the Korean version of the THINC-it tool (THINC-it-K) in adult patients with major depressive disorder (MDD).

METHODS

: Subjects aged 19-65 years with recurrent MDD experiencing moderate to severe major depressive episode (n = 44) were evaluated and compared to age and sex matched healthy controls (n = 44). Subjects completed the THINC-it-K which includes variants of the Identification Task (IDN) using Choice Reaction Time, One-Back Test, Digit Symbol Substitution Test, Trail Making Test-Part B, and the Perceived Deficits Questionnaire for Depression-5-item (PDQ-5-D).

RESULTS

: A total of 75.0% of patients with MDD exhibited cognitive performance 1 standard deviation or below. The differences in Spotter ( = 0.001), Codebreaker ( = 0.001), PDQ-5-D ( ＜ 0.001) and objective THINC-it-K composite score ( = 0.002) were significant between the two groups. Concurrent validity of the THINC-it-K based on a calculated composite score was good (r = 0.856, ＜ 0.001), and ranges for each component tests were from 0.076 (IDN) to 0.928 (PDQ-5-D).

CONCLUSION

: The THINC-it-K exhibits good reliability and validity in adults with MDD. It could be a useful tool for the measurement of cognitive deficits in persons with MDD and should be implemented in clinical practice.