Familial liability to schizophrenia and mood disorders and cognitive impairment in psychosis

Effect of polygenic risk score, family load of schizophrenia and exposome risk score, and their interactions, on the long-term outcome of first-episode psychosis

BACKGROUND

Consistent evidence supports the involvement of genetic and environmental factors, and their interactions, in the etiology of psychosis. First-episode psychosis (FEP) comprises a group of disorders that show great clinical and long-term outcome heterogeneity, and the extent to which genetic, familial and environmental factors account for predicting the long-term outcome in FEP patients remains scarcely known.

METHODS

The SEGPEPs is an inception cohort study of 243 first-admission patients with FEP who were followed-up for a mean of 20.9 years. FEP patients were thoroughly evaluated by standardized instruments, with 164 patients providing DNA. Aggregate scores estimated in large populations for polygenic risk score (PRS-Sz), exposome risk score (ERS-Sz) and familial load score for schizophrenia (FLS-Sz) were ascertained. Long-term functioning was assessed by means of the Social and Occupational Functioning Assessment Scale (SOFAS). The relative excess risk due to interaction (RERI) was used as a standard method to estimate the effect of interaction of risk factors.

RESULTS

Our results showed that a high FLS-Sz gave greater explanatory capacity for long-term outcome, followed by the ERS-Sz and then the PRS-Sz. The PRS-Sz did not discriminate significantly between recovered and non-recovered FEP patients in the long term. No significant interaction between the PRS-Sz, ERS-Sz or FLS-Sz regarding the long-term functioning of FEP patients was found.

CONCLUSIONS

Our results support an additive model of familial antecedents of schizophrenia, environmental risk factors and polygenic risk factors as contributors to a poor long-term functional outcome for FEP patients.

Validity and utility of a set of clinical criteria for cognitive impairment associated with psychosis (CIAPs)

Schizophrenia and other psychoses display a common profile of mild to moderate cognitive deficits that are associated with poor functional outcomes. Cognitive impairment is usually evaluated by neuropsychological assessment, and interview-based measures with good psychometric properties and high utility for clinical practice are now available. However, the extent to which a set of clinical criteria can be used as proxy measures of cognitive deficits in this population has not been tested. This study aimed to examine the empirical validity of a set of clinical criteria for cognitive impairment associated with psychosis (CIAPs). Ninety-eight patients with non-pure affective psychosis and 50 healthy-matched controls were included. The CIAPs criteria were empirically tested against antecedent, concurrent and outcome validators and by means of a neuropsychological evaluation based on MATRICS Consensus Cognitive Battery (MCCB). The CIAPs criteria showed strong associations with outcomes and certain antecedent validators and moderate associations with concurrent validators. The CIAPs criteria achieved superior neuropsychological validity compared to current DSM 5 criteria for schizophrenia, the B-criterion of DSM 5 schizophrenia or a combination of both criteria. Cognitive impairment associated with psychosis can be clinically assessed and is a useful tool for clinical practice and predicting outcomes of schizophrenia and related psychosis.

Influence of interactions between genes and childhood trauma on refractoriness in psychiatric disorders

Psychiatric disorders are excellent disease models in which gene-environmental interaction play a significant role in the pathogenesis. Childhood trauma has been known as a significant environmental factor in the progress of, and prognosis for psychiatric illness. Patients with refractory illness usually have more severe symptoms, greater disability, lower quality of life and are at greater risk of suicide than other psychiatric patients. Our literature review uncovered some important clinical factors which modulate response to treatment in psychiatric patients who have experienced childhood trauma. Childhood trauma seems to be a critical determinant of treatment refractoriness in psychotic disorder, bipolar disorder, major depressive disorder, and post-traumatic stress disorder. In patients with psychotic disorders, the relationship between childhood trauma and treatment-refractoriness appears to be mediated by cognitive impairment. In the case of bipolar disorder, the relationship appears to be mediated by greater affective disturbance and earlier onset, while in major depressive disorder the mediating factors are persistent, severe symptoms and frequent recurrence. In suicidal individuals, childhood maltreatment was associated with violent suicidal attempts. In the case of PTSD patients, it appears that childhood trauma makes the brain more vulnerable to subsequent trauma, thus resulting in more severe, refractory symptoms. Given that several studies have suggested that there are distinct subtypes of genetic vulnerability to childhood trauma, it is important to understand how gene-environment interactions influence the course of psychiatric illnesses in order to improve therapeutic strategies.