Validation of the THINC-It Tool for Assessment of Cognitive Impairment in Patients with Bipolar Depression

Cognitive impairment is one of the core features of bipolar depression. A unified, reliable, and valid assessment tool is key to screening and assessing cognitive impairment. The THINC-Integrated Tool (THINC-it) is a simple and quick battery for screening cognitive impairment in patients with major depressive disorder. However, the use of the tool has not been validated in patients with bipolar depression.

The cognitive functions of 120 patients with bipolar depression and 100 healthy controls were evaluated using the THINC-it tool including Spotter, Symbol Check, Codebreaker, Trials, and the only one subjective test (PDQ-5-D) and five corresponding standard tests. A psychometric analysis of the THINC-it tool was performed.

The overall Cronbach's alpha coefficient of the THINC-it tool was 0.815. The intra-group correlation coefficient (ICC) of retest reliability ranged from 0.571 to 0.854 (P<0.001), while the correlation r of parallel validity ranged from 0.291 to 0.921 (P<0.001). There were significant differences in the two groups Z-scores of THINC-it total score, Spotter, Codebreaker, Trails, and PDQ-5-D (P<0.05). Construct validity was analyzed using exploratory factor analysis (EFA). The Kaiser-Meyer-Olkin (KMO) value was 0.749. Using Bartlett's Sphericity test, the χ ² (10) value was 198.257 (P<0.001). The factor loading coefficients of Spotter, Symbol Check, Codebreaker, and Trails on the common factor 1 were -0.724, 0.748, 0.824, and -0.717, respectively, and the factor loading coefficient of PDQ-5-D on the common factor 2 was 0.957. Results revealed that the correlation coefficient of the two common factors was 0.125.

The THINC-it tool has good reliability and validity in assessing patients with bipolar depression.