In the discussion of the inclusion of an at-risk syndrome of psychosis in DSM-V, the validity of current at-risk criteria had been questioned based on studies reporting much higher prevalence rates of psychotic-like experiences in general population samples (GPS) compared to psychotic disorders. Thus the 3-month prevalence of at-risk criteria and symptoms in GPS, age 16–35, was assessed by trained clinicians in telephone interviews using established standardized assessments.

Of 85 enrolled persons, 60 persons (70.5%) participated, two of them met exclusion criteria (psychosis, language problems). The 22 psychopathological at-risk symptoms were assessed for their occurrence and severity within the three months prior to the telephone interview using the

1. (i) Schizophrenia Prediction Instrument, Adult version (SPI-A) and

2. (ii) the Structured Interview for Prodromal Syndromes (SIPS).

Only one person (1.7%) fulfilled ‘attenuated psychotic symptoms’ (APS)-criteria according to SIPS. At 1.7%, the 3-month prevalence of at-risk criteria was rather low; at 20.7%, the prevalence of sub-threshold at-risk symptoms, however, was much higher. Yet the presence of these sub-threshold symptoms was already associated with lower psychosocial functioning and with psychiatric axis I diagnoses.