Axis I diagnoses and transition to psychosis in clinical high-risk patients EPOS project: prospective follow-up of 245 clinical high-risk outpatients in four countries.

BACKGROUND: In selected samples, a considerable number of patients at clinical high risk of psychosis (CHR) are found to meet criteria for co-morbid clinical psychiatric disorders. It is not known how clinical diagnoses correspond to or even predict transitions to psychosis (TTP). Our aim was to examine distributions of life-time and current Axis I diagnoses, and their association with TTP in CHR patients.

METHODS: In the EPOS (European Prediction of Psychosis Study) project, six European outpatient centres in four countries examined 245 young help-seeking patients, who fulfilled the inclusion criteria for clinical risk of psychosis according to the Structured Interview for Prodromal Syndromes (SIPS 3.0) or the Bonn Scale for the Assessment of Basic Symptoms - Prediction List basic symptoms (BASBS-P). Patients who had experienced a psychotic episode lasting more than one week were excluded. Baseline and life-time diagnoses were assessed by the Structured Clinical Interview for DSM-IV (SCID-I). TTP was defined by continuation of BLIPS for more than seven days and predicted in Cox-regression analysis.

RESULTS: Altogether, 71% of the CHR patients had one or more life-time and 62% one or more current SCID-I diagnosis; about a half in each category received a diagnosis of life-time depressive and anxiety disorder. Currently, 34% suffered from depressive and 39% from anxiety disorder. Four percent received a current SCID diagnosis of bipolar, and 6.5% of somatoform disorder. During follow-up, 37 (15.1%) patients had developed full-blown psychosis. In bivariate analyses, current non-psychotic bipolar disorder associated significantly with TTP. In multivariate analyses, current bipolar disorder, somatoform and unipolar depressive disorders associated positively, and anxiety disorders negatively, with TTP.

CONCLUSIONS: Both life-time and current mood and anxiety disorders are highly prevalent among clinical help-seeking CHR patients and need to be carefully evaluated. Among CHR patients, occurrence of bipolar, somatoform and depressive disorders seems to predict TTP, while occurrence of anxiety disorder may predict non-transition to psychosis.