Validation of the Bipolar Prodrome Symptom Interview and Scale-Abbreviated Prospective (BPSS-AP) in a clinical sample and healthy controls.

BACKGROUND: After the existence of a bipolar disorder (BD) prodrome was established, the development of clinical rating instruments has become relevant that are sufficiently brief to be implemented in real-world clinical practice and that are designed to identify individuals at-risk for BD. This study aimed to validate a shorter version of the Bipolar Prodrome Symptom Interview and Scale (BPSS), the BPSS-Abbreviated Prospective (BPSS-AP), for use among clinical populations. METHODS: Altogether, 104 adults, comprising individuals diagnosed with BD (n = 17, mania: n = 8, hypomania: n = 9), with major depressive disorder (MDD, n = 38, all currently depressed), and healthy controls (HCs, n = 49), underwent BPSS-AP interviews. The psychometric properties of the BPSS-AP were evaluated, including internal consistency, convergent validity, discriminant validity, and factor structure. RESULTS: The median (IQR) age was 29 (23-38), 40 (23-55), and 25 (22-28) years, for the BD, MDD, and HC groups, respectively. The BPSS-AP showed excellent internal consistency (Cronbach's α = 0.95). Convergent validity between the BPSS-AP and Young Mania Rating Scale (YMRS) was high (r > 0.7). The BPSS-AP discriminated patients with BD from those with MDD (P < .001) and from HCs (P < .001). LIMITATIONS: The study design precludes assessment of the predictive validity of the BPSS-AP. CONCLUSIONS: This study found that the BPSS-AP, a more concise and feasible version of the semi-structured interview for identifying individuals at risk of developing BD, has satisfactory psychometric properties. There is room for further validation and application of the BPSS-AP in clinical settings to evaluate its utility in research and clinical care.