Interplay of Subjective Symptoms Across the Stages of the Schizophrenia Spectrum

Schizophrenia (SPR) spectrum disorders involve various subjective symptoms, including disruptions in self-awareness, cognitive complaints, and schizotypy. While tools such as the Examination of Anomalous Self-Experience (EASE), Frankfurt Complaint Questionnaire (Frankfurter Beschwerde-Fragebogen, FBF), and Chapman Psychosis Proneness Scales (CPPS) have been employed, research on their interrelations across different stages of the SPR spectrum remains limited, particularly in ultra-high risk (UHR) and SPR groups.

This study examined the EASE, FBF, and CPPS scores among healthy controls (HC), individuals at UHR, and those with SPR. Group differences and the interplay of subjective symptoms were analysed to understand how these dimensions interact and evolve across the psychosis continuum.

HCs scored significantly lower on all subjective symptom measures compared to both UHR and SPR groups. Specifically, the HC group (0.82±1.51) scored significantly lower on the EASE than both the UHR (13.90±9.67) and SPR (10.13±9.16) groups (p<0.001). Similarly, the FBF scores for HCs (9.75±10.30) were significantly lower than for the UHR (36.27±22.73, p<0.001) and SPR (26.77±26.15, p=0.017) groups. Significant differences were also found in CPPS subscales, with HCs scoring significantly lower than UHR and SPR groups on the Physical Anhedonia Scale (UHR, p<0.001; SPR, p=0.026) and the Social Anhedonia Scale (HC vs. UHR: p<0.001, HC vs. SPR: p<0.001). The differences in subjective disturbances between the UHR and SPR groups were less pronounced and not statistically significant for any of the main measures. Stronger associations among the EASE, FBF, and CPPS were observed in the SPR group.

The findings indicate that the UHR and SPR groups share elevated levels of disturbed subjective experiences, with the SPR group showing greater disruptions in the interplay of these experiences. These findings suggest a continuous spectrum of shared experiential anomalies and support the value of integrated assessment approaches. Such combined evaluations may enhance the precision of early psychosis risk detection and longitudinal monitoring, offering a foundational basis for future interventions grounded in phenomenological understanding.