The nature of schizotypy in early psychosis

Introduction: Cognitive models of psychosis suggest that low level anomalous experiences form an important foundation for later psychotic symptoms to be built upon. However, prevalence studies of psychotic-like experiences in the general population reveal high levels of symptomatology (e.g. van Os et al, 2000). This makes distinguishing these individuals from first-episode psychosis samples difficult on the presence of symptoms alone. Experience per se is arguably neither pathological nor sufficient to highlight an individual as being at-risk of developing psychosis. There is a need to look more closely at the dimensions of these experiences. It is suggested that the frequency of low-level psychotic experiences is particularly important as this may drive the ‘search for meaning’ (Garety etal, 2001; Birchwood, 1996). This study investigates the notion that psychotic symptoms exist on a continuum of frequency.
Method: Two groups of participants – a recovering early psychosis sample (N = 120) and a non-clinical student sample (N = 808) – completed a modified version of a self-report measure of schizotypy to assess low-level psychotic symptom frequency. Anxiety, depression and schema were also assessed in both samples. In addition, current psychotic symptoms were assessed in the clinical sample.
Results: Schizotypal symptoms are common in both clinical and non-clinical populations. However, they appear to occur more frequently in clinical samples. Social anxiety and paranoia appear to be particularly important discriminators, as do anomalous symptoms, albeit to a lesser extent. In addition, whilst social anxiety and paranoia correlated strongly with emotional and psychological variables, anomalous experiences did not. These symptoms could be attributed to physiological/neuropsychological disturbances.
Discussion: The fact that low-level psychotic symptomatology is common in the general population has a positive implication in normalising these experiences in clinical populations. Furthermore, social anxiety and paranoia are highlighted as important points of therapeutic focus and may be mostly related to emotional and schematic disturbances.