Comparing the prodrome of schizophrenia-spectrum psychoses and affective disorders with and without psychotic features.

OBJECTIVE Following encouraging results in the early detection of psychotic disorders, interest in the early detection of affective, especially bipolar disorders, has recently been renewed. However, the differentiation between affective disorders with and without psychotic features is often missing, although it has been suggested that affective disorders with psychotic features may be distinct from those without psychotic features and closely linked to non-affective psychoses. METHODS We compared the prodromal symptoms of patients who had sought help at an early detection center; had been assessed at baseline with the Structured Interview for Prodromal Syndromes (SIPS); and who, within 53 months on average, developed schizophrenia-spectrum psychosis (pre-SCZ; n=51), affective disorder with psychotic features (pre-AD-P; n=7), or affective disorder without psychotic features (pre-AD-noP; n=16). RESULTS While pre-SCZ scored slightly higher on most positive symptoms than pre-AD, pre-AD-P and pre-SCZ scored comparably across the SIPS; moreover, pre-AD-noP and pre-SCZ differed on most subscales and items, particularly on the positive and negative dimensions. Furthermore, pre-AD-P scored higher on positive symptoms than pre-AD-noP. CONCLUSIONS Our results suggest that, in the early detection of affective disorders, those that might take on a psychotic form and those with a non-psychotic course need to be considered separately. While the current at-risk criteria for psychosis function well in detecting those with a psychotic course, those with a non-psychotic course would benefit from the development and evaluation of new at-risk criteria and new early detection instruments.