The reliability and validity of the Chinese Polarity Inventory

For the simultaneous measurement of manic and depressive symptoms, the Chinese Polarity Inventory (CPI), a 20-item self-report scale, was developed. A total of 329 depressive and 356 manic/hypomanic patients were recruited in this scale developmental study in China. All patients completed the CPI and either the Chinese version of the Hamilton Depression Rating Scale (for depressed subjects) or the Chinese version of the Bech-Rafaelsen Mania Scale (for manic subjects). The CPI was found to have excellent reliability and satisfactory concurrent validity. Construct validity analysis was performed using principal component analysis, which yielded 4 clinically meaningful factors: activity, pleasurability, capability and irritability. The CPI was sensitive in differentiating different severities of depression and mania. However, its ability to differentiate mixed phase from other mood states and its sensitivity to changes during the treatment still need to be studied further.