Evidence that polygenic risk for psychotic disorder is expressed in the domain of neurodevelopment, emotion regulation and attribution of salience.

BACKGROUND: The liability-threshold model of psychosis risk predicts stronger phenotypic manifestation of the polygenic risk score (PRS) in the healthy relatives of patients, as compared with healthy comparison subjects. METHODS: First-degree relatives of patients with psychotic disorder (871 siblings and 812 parents) and healthy comparison subjects (n = 523) were interviewed three times in 6 years. Repeated measures of two psychosis phenotypes, the Community Assessment of Psychic Experiences (CAPE; self-report - subscales of positive, negative and depressive symptoms) and the Structured Interview for Schizotypy - Revised (SIS-R; clinical interview - subscales of positive and negative schizotypy), were examined for association with PRS. Interview-based lifetime rate of depressive and manic episodes were also examined, as was association with repeated measures of intelligence quotient (IQ). RESULTS: In the relatives, PRS was associated with CAPE/SIS-R total score (respectively, B = 0.12, 95% CI 0.02-0.22 and B = 0.11, 95% CI 0.02-0.20), the SIS-R positive subscale (B = 0.16, 95% CI 0.04-0.28), the CAPE depression subscale (B = 0.21, 95% CI 0.07-0.34), any lifetime affective episode (OR 3.1, 95% CI 1.04-9.3), but not with IQ (B = -1.8, 95% CI -8.0 to 4.4). In the controls, similar associations were apparent between PRS on the one hand and SIS-R total score, SIS-R positive, SIS-R negative, any lifetime affective episode and, in contrast, lower IQ (B = -8.5, 95% CI -15.5 to -1.6). CONCLUSIONS: In non-ill people, polygenic risk for psychotic disorder is expressed pleiotropically in the domain of neurodevelopment, emotion regulation and attribution of salience. In subjects at elevated genetic risk, emerging expression of neurodevelopmental alterations may create floor effects, obscuring genetic associations.

Clinical high risk for psychosis: the association between momentary stress, affective and psychotic symptoms.

OBJECTIVE: The aim of this study was to assess associations between momentary stress and both affective and psychotic symptoms in everyday life of individuals at clinical high risk (CHR), compared to chronic psychotic patients and healthy controls, in search for evidence of early stress sensitization. It also assessed whether psychotic experiences were experienced as stressful. METHOD: The experience sampling method was used to measure affective and psychotic reactivity to everyday stressful activities, events and social situations in 22 CHR patients, 24 patients with a psychotic disorder and 26 healthy controls. RESULTS: Multilevel models showed significantly larger associations between negative affect (NA) and activity-related stress for CHR patients than for psychotic patients (P = 0.008) and for CHR compared to controls (P < 0.001). Similarly, the association between activity-related stress and psychotic symptoms was larger in CHR than in patients (P = 0.02). Finally, the association between NA and symptoms (P < 0.001) was larger in CHR than in patients. CONCLUSION: Stress sensitization seems to play a role particularly in the early phase of psychosis development as results suggest that CHR patients are more sensitive to daily life stressors than psychotic patients. In this early phase, psychotic experiences also contributed to the experience of stress.

'False-positive' self-reported psychotic experiences in the general population: an investigation of outcome, predictive factors and clinical relevance.

AIMS.: Self-reported psychotic experiences (SRPE) by individuals from the general population are often unconfirmed by clinical interview and referred to as 'false-positive' (FP) SRPE. FP SRPE have been suggested to represent the mildest form of risk along the extended psychosis continuum. However, little is known about their (clinical) outcome and evolution over time. Aims of this study were to prospectively examine, in individuals with FP SRPE, (1) the prevalence of remission, persistence and transition to validated PE at 3-year follow-up; (2) potential baseline psychopathological and psychosocial predictors of persistence of FP SRPE and transition to validated PE; and (3) whether those with persistent FP SRPE and validated PE already differed on psychopathology and psychosocial factors at baseline. We tested the hypotheses that (i) individuals with FP SRPE would be more likely to have SRPE and validated PE at follow-up; and (ii) that FP SRPE would be predictive of lower functioning and more psychopathology and help-seeking behaviour at follow-up. METHODS.: Baseline (n = 6646) and 3-year follow-up (n = 5303) data of the second the Netherlands Mental Health Survey and Incidence Study (NEMESIS-2), a general population research project on prevalence, incidence, course and consequences of psychiatric disorders was used. Self-report of PE was followed by clinical interview to determine clinical validity. The presence of mood, anxiety and substance use disorders, childhood adversity, help-seeking and functioning as well as PE characteristics (number, frequency, distress and impact) were used in the analyses which included only individuals with complete data for both assessments waves (n = 4683). RESULTS.: At baseline, 454 participants had any FP SRPE; of these 372 participants had complete follow-up data available. Those with baseline FP SRPE were significantly more likely to report SRPE (OR = 3.58; 95% CI 2.38-5.40, p < 0.001) and validated PE (OR = 6.26; 95% CI 3.91-10.02, p < 0.001) at follow-up. Baseline FP SRPE also predicted the presence of mood and anxiety disorders, reduced functioning and help-seeking at follow-up. Several baseline psychopathological, psychosocial and PE characteristics were predictive for the persistence of SRPE. These factors also differentiated groups with FP SRPE or validated PE from those with remitted FP SRPE at follow-up. CONCLUSIONS.: 'FP SRPE' are not truly 'false' as they index risk for the development of clinically relevant psychotic symptoms, development of mood and anxiety disorders and reduced functioning. Self-reported PE, even unconfirmed, warrant 'watchful waiting' and follow-up over time, especially when they are reported by individuals with reduced psychosocial functioning and general psychiatric problems.