The full spectrum of clinical stages of psychosis at prison entry: prevalence and concurrent validity of symptom screening.

Purpose: Despite the high rates of psychotic disorders amongst people in prison, current prison mental health screening approaches have not included assessment of the full psychosis spectrum to capture those at-risk of an emerging psychosis as well as those with established illness nor assessed the concurrent validity of psychosis symptom screening.

Methods: Using a clinical staging approach to establish the prevalence of Ultra High Risk (UHR), first episode of psychosis (FEP) and established psychosis (EP) groups, 291 adults entering custody in two prison reception centres in NSW completed a two-stage (screening and validation) interview process. The Comprehensive Assessment of At-Risk Mental States (CAARMS) was used to determine the clinical stages of psychosis and concurrent validity of symptom screening in identifying individuals on the psychosis spectrum was formally assessed.

Results: Amongst men and women entering prison, almost one quarter (24.1%) met UHR criteria, 5.1% met the FEP threshold and 10.6% had an established psychosis. Those on the psychosis spectrum reported greater disadvantage across sociodemographic and justice factors. The presence of perceptual disturbance and paranoid beliefs emerged as the two best screening items for identifying those with an underlying psychosis spectrum illness.

Conclusion: The prevalence of psychosis spectrum illness, including the UHR state, amongst those entering prison is high. Current prison mental health approaches should include screening for the presence of perceptual disturbances and paranoid beliefs to improve the detection of psychosis spectrum illness.