Plasma levels of neurotrophin 4/5, NGF and pro-BDNF influence transition to mental disorders in a sample of individuals at ultra-high risk for psychosis.

BACKGROUND: Neurotrophins (NTs) and their precursors (pro-NTs) are polypeptides with important roles in neuronal development, differentiation, growth, survival and plasticity, as well as apoptosis and neuronal death. Imbalance in NT levels were observed in schizophrenia spectrum disorders, but evidence in ultra-high risk for psychosis (UHR) samples is scarce. METHODS: A naturalistic sample of 87 non-help-seeking UHR subjects and 55 healthy controls was drawn from the general population. Blood samples were collected and NT-3, NT-4/5, BDNF, pro-BDNF, NGF, pro-NGF were analyzed through enzyme linked immunosorbent assay (ELISA). Information on cannabis and tobacco use was also collected. Logistic regression models and path analysis were used to control for confounders (tobacco, age, cannabis use). RESULTS: NT-4/5 was significantly decreased, and pro-BDNF was significantly increased in UHR individuals compared to controls. Cannabis use and higher NGF levels were significantly related to transition to psychiatric disorders among UHR subjects. Increased pro-BDNF and decreased NT-4/5 influenced transition by the mediation of perceptual abnormalities. CONCLUSIONS: Our study shows for the first time that NTs are altered in UHR compared to healthy control individuals, and that they can be a predictor of transition to psychiatric illnesses in this population. Future studies should employ larger naturalistic samples to confirm the findings.

Childhood maltreatment in individuals at risk of psychosis: Results from the Brazilian SSAPP cohort.

BACKGROUND: Childhood maltreatment is a known risk factor for the development of mental disorders, such as psychotic symptoms. An extensive body of literature about childhood maltreatment and mental health has been developed in wealthy countries, but information about this connection is lacking in developing countries. AIMS: To explore a possible relationship between childhood maltreatment and ultra-high risk of psychosis in a non-help-seeking population in a low- and middle-income country. METHODS: A household survey was conducted in Sao Paulo, Brazil, involving over 2,500 individuals aged 18-30 years who were randomly selected from the general population. The participants underwent screening with the Prodromal Questionnaire. Ultra-high risk status was assessed using the Structured Interview for Prodromal Syndromes, and childhood maltreatment was assessed using the Childhood Trauma Questionnaire. The final sample comprised 87 ultra-high risk individuals and 115 controls. RESULTS: Childhood maltreatment was significantly more present among ultra-high risk individuals. In ultra-high risk individuals, physical and emotional neglect were inversely related to grandiosity symptoms, physical abuse was related to perceptual abnormalities and physical neglect was related to disorganized speech and thought. CONCLUSION: This is the first study to investigate the relationship between childhood maltreatment and ultra-high risk status and psychopathological features in a large Latin American sample. Further studies in this field are necessary to better understand the specific influence of various early life adversities on psychosis risk.