21580_rietdijk F.indd

Latent class analyses in the general population have found that the psychosis phenotype has four classes. Could this be replicated in a sample of help-seeking people accessing mental health services for symptoms of non-psychotic mental disorders? All patients (18-35 yrs old) referred for non-psychotic mental health problems to the secondary mental healthcare service in The Hague between February 2008 to February 2010 (N=3694), were included. Patients completed the Prodromal Questionnaire (PQ) and latent class analysis was applied to explore the number, size and symptom-profiles of the different classes. The latent class analysis resulted in four classes. Subjects placed in Class 1 (N=448, 12.2%) endorsed almost all PQ-items, were more often diagnosed as psychotic or at high risk of developing psychosis, and were referred for treatment for posttraumatic stress and mood disorders. In Class 2 (N=1125, 30.3%) paranoia and mood symptoms were more prevalent. Subjects often meet criteria for the high risk group and were often diagnosed with mood disorders or personality disorders. Class 3 (N=1329, 36.2%) scored high on disturbed mood and anxiety and were treated for these symptoms. Class 4 (N= 792, 21.3%) represents the ‘normative’ group with low probabilities for all items. Subjects were more likely to be male and diagnosed with anxiety disorders, eating disorders and relationship problems. The results support the hypothesis that a representation in four classes of psychotic-like experiences can also be applied in a help-seeking population.