A review of vulnerability and risks for schizophrenia: beyond the two hit hypothesis

Schizophrenia risk has often been conceptualized using a model which requires two hits in order to generate the clinical phenotype-the first as an early priming in a genetically predisposed individual and the second a likely environmental insult. The aim of this paper was to review the literature and reformulate this binary risk-vulnerability model. We sourced the data for this narrative review from the electronic database PUBMED. Our search terms were not limited by language or date of publication. The development of schizophrenia may be driven by genetic vulnerability interacting with multiple vulnerability factors including lowered prenatal vitamin D exposure, viral infections, smoking intelligence quotient, social cognition cannabis use, social defeat, nutrition and childhood trauma. It is likely that these genetic risks, environmental risks and vulnerability factors are cumulative and interactive with each other and with critical periods of neurodevelopmental vulnerability. The development of schizophrenia is likely to be more complex and nuanced than the binary two hit model originally proposed nearly thirty years ago. Risk appears influenced by a more complex process involving genetic risk interfacing with multiple potentially interacting hits and vulnerability factors occurring at key periods of neurodevelopmental activity, which culminate in the expression of disease state. These risks are common across a number of neuropsychiatric and medical disorders, which might inform common preventive and intervention strategies across non-communicable disorders.

Emotions mediate the relationship between autistic traits and disordered eating: a new autistic-emotional model for eating pathology

The aim of the study was to assess the extent of overlap between autistic traits, body dissatisfaction and disordered eating and to explore the mediating effects of negative attitudes towards emotional expression and emotion dysregulation. The sample comprised 416 university students (82% females, 17-48 years [M=19.76, SD=3.85]), who completed an online questionnaire assessing eating attitudes and behaviours (including dieting, bulimia and oral control), body dissatisfaction, and autistic traits (including the Autism Quotient [AQ] and its related subscales as well as the Empathising Quotient). Attitudes towards emotional expression and emotion regulation were also assessed. Results revealed that eating pathology correlated highly with all AQ subscales, with the exception of the attention to detail subscale. However, there was no significant relationship between empathising and eating pathology. Path-analyses indicated that emotion dysregulation, but not negative attitudes towards emotional expression, was a significant mediator of the relationship between AQ, body dissatisfaction and eating pathology. Direct relationships were also obtained for the AQ-bulimia and the AQ-oral control paths. Prevention and early intervention programs for eating pathology would likely benefit from addressing abnormalities in emotion processes in individuals who score highly on measures of autistic traits.