Presence of Psychotic Spectrum Symptoms Before Age 12 in Schizophrenia Patients: A Retrospective Study on Clinical Implications for Early Detection and Intervention

Background/Objectives: Schizophrenia is a severe psychiatric disorder, with onset typically occurring in late adolescence or early adulthood. Early identification of psychotic symptoms, especially those occurring before age 12, has been linked to better long-term outcomes. This study aims to assess the presence of psychotic spectrum symptoms before the age of 12 in adult schizophrenia patients and explore their clinical implications for early detection and intervention. Methods: This retrospective, observational study included 170 adult patients diagnosed with schizophrenia, confirmed by the SCID-5. Patients were recruited from the University of Siena Medical Center and completed the modified lifetime version of the Psychotic Spectrum Self-Report (PSY-SR) questionnaire, which assessed the onset of specific psychotic symptoms before and after age 12. Symptom severity was evaluated using the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression Scale (CGI). This study also examined the impact of the duration of untreated psychosis (DUP) on symptom severity. Results: In our cohort, 21% of patients exhibited prodromal symptoms before age 12 (95% CI: 15–27%). Prodromal symptoms were linked to a 9.53-point increase in the BPRS scores (p = 0.0478) and a 0.50-point increase in the CGI scores (p = 0.0347). The age of symptom onset negatively correlated with the BPRS scores (p < 0.0001), with each year of delay resulting in a 1.33-point decrease. The DUP correlated significantly with both the BPRS (ρ = 0.97) and CGI scores (ρ = 0.94). The multivariate analysis revealed that a longer DUP was associated with significant increases in both scores: a 27.16-point increase in the BPRS (p < 0.0001) for a moderate DUP and a 67.51-point increase (p < 0.0001) for a severe DUP. The CGI scores increased by 1.11 points with a moderate DUP and 3.17 points with a severe DUP (p < 0.0001). However, the interaction between the DUP and prodromal symptoms at age 12 was not significant, indicating similar impacts of the DUP regardless of early symptom onset. Conclusions: The results support the critical importance of early detection and intervention in schizophrenia. Early psychotic spectrum symptoms, particularly those occurring before age 12, are significant predictors of later severity and functional impairment. This study underscores the value of screening tools like the PSY-SR for identifying prodromal symptoms and facilitating timely intervention. Our findings highlight the need for the early identification of psychotic symptoms, particularly in at-risk populations, to improve long-term outcomes. Intervening before the onset of full-blown psychosis may reduce the severity of schizophrenia and promote better clinical outcomes.