Do psychosis prodrome onset negative symptoms predict first presentation negative symptoms?

Background: Negative symptoms have been previously reported during the psychosis prodrome, however our understanding of their relationship with treatment-phase negative symptoms remains unclear.

Objectives: We report the prevalence of psychosis prodrome onset negative symptoms (PONS) and ascertain whether these predict negative symptoms at first presentation for treatment.

Methods: Presence of expressivity or experiential negative symptom domains was established at first presentation for treatment using the Scale for Assessment of Negative Symptoms (SANS) in 373 individuals with a first episode psychosis. PONS were established using the Beiser Scale. The relationship between PONS and negative symptoms at first presentation was ascertained and regression analyses determined the relationship independent of confounding.

Results: PONS prevalence was 50.3% in the schizophrenia spectrum group (n=155) and 31.2% in the non-schizophrenia spectrum group (n=218). In the schizophrenia spectrum group, PONS had a significant unadjusted (χ(2)=10.41, P<0.001) and adjusted (OR=2.40, 95% CI=1.11-5.22, P=0.027) association with first presentation experiential symptoms, however this relationship was not evident in the non-schizophrenia spectrum group. PONS did not predict expressivity symptoms in either diagnostic group.

Conclusion: PONS are common in schizophrenia spectrum diagnoses, and predict experiential symptoms at first presentation. Further prospective research is needed to examine whether negative symptoms commence during the psychosis prodrome.