All participants enrolled as probable cases were interviewed using the Diagnostic Interview for Psychosis and Affective Disorders (DI-PAD) (Supplementary Information: DI-PAD). We developed the DI-PAD specifically for the GPC study using the same principles as were applied in the development of the Diagnostic Interview for Psychosis – Diagnostic Module (DIP-DM) (Castle et al., 2006). The DI-PAD is a semi-structured clinical interview that includes two modules: Diagnostic Module and Substance Abuse Module. The DI-PAD is administered by mental health professionals and requires more than a simple notation of presence or absence of a symptom. Specific training is necessary to ensure reliability of ratings. At this time, the DI-PAD is available in English, Portuguese, and Spanish.
