Developmental trajectories of psychosis in population-based samples: interplay between early adversity and familial risk

Lead Research Organisation: King's College London
Department Name: Inst of Psychiatry School Offices

Abstract

Mental health problems such as psychosis (e.g., schizophrenia) can be extremely disabling and result in massive costs for the individual, NHS services and society in general. Greater understanding of what factors are involved in development and persistence of such disorders would assist attempts to prevent and treat them. One of the major factors thought to cause psychosis is an individual‘s genetic make-up but environmental factors are also thought to play a role, possibly in combination with genes. Therefore, I propose to investigate whether individuals who have been exposed to potentially distressing experiences in childhood (severely beaten by or separated from their parents) and have a genetic risk (positive family history) are more likely to experience psychotic symptoms (such as hearing voices) over a long period of time and require treatment for psychosis during the life-course than individuals with only one or neither of these factors. To test this proposition I will analyse data from four different longitudinal studies: three general population birth cohorts in adolescence and adulthood and a 10-year follow-up of clinically diagnosed psychosis patients on whom information is available about their family and childhood history and experience of psychotic symptoms and mental health treatment at different time points.

Technical Summary

Aim: To develop a greater understanding of how exposure to adverse childhood experiences and their interplay with family history of psychosis can influence the developmental course of psychosis throughout adolescence and adulthood.



Objectives:



1. Examine qualitative differences in the form and content of psychotic symptoms experienced by environmentally versus neurodevelopmentally vulnerable children and potential links to comorbidity.



2. Investigate how types of childhood adversity and familial liability steer individuals towards a pathway leading to psychosis rather than other psychiatric disorders.



3. Explore the role of early environmental adversity versus neurodevelopmental deficits together with familial liability in the persistence and longer-term outcomes of psychosis.



Design: Four longitudinal studies will be utilised: a UK population-based sample of twins aged 12 years and their mothers; a UK birth cohort aged 18 years; a New Zealand birth cohort aged 38 years; and a 10-year follow-up of epidemiologically sampled first-episode psychosis patients.



Methodology:



Study 1 - E-Risk: Thematic analysis will be conducted on twins‘ narrative description of psychotic symptoms at age 12, to explore differences in type and content of symptoms according to victimisation history, neurodevelopmental deficits, and comorbidity. Prevalence rates of different forms of childhood maltreatment and their interplay with familial risk will be compared in mothers with lifetime diagnoses of psychosis, depression, mania and no psychiatric disorder.



Study 2 - ALSPAC: Differences in prevalence rates of childhood victimisation and their interaction with familial liability to psychosis will be explored amongst the following prospectively obtained groups: no psychotic symptoms at 12 or 17 years, psychotic symptoms at both 12 and 17 years, symptoms only at 12 years, and new onsets at 17.



Study 3 - Dunedin: Comparison of different psychosis trajectories between 11 - 38 years and utilisation of services in terms of familial risk and prospectively assessed developmental risk factors (neurodevelopmental deficits, victimisation, and cannabis use).



Study 4 - AESOP: The course of psychotic disorder, service utilisation and psychosocial outcomes assessed prospectively over a 10-year period will be compared for first-episode patients with and without a retrospectively reported history of childhood adversity and parental psychiatric disorder.



Scientific and medical opportunities: Improved aetiological understanding of the course of psychosis has massive implications for prevention and treatment. Identification of malleable environmental mechanisms will enable clinicians to provide more effective interventions to reduce the risk of vulnerable children developing disabling and potentially life-long mental health problems and promote resilience. Ultimately, this project intends to improve well-being across the lifespan.

Publications

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