The aetiology of psychosis high-risk mental states during adolescence in the ALSPAC cohort

Lead Research Organisation: University of Bristol
Department Name: Community-Based Medicine

Abstract

The presence of psychotic symptoms such as delusions and hallucinations, along with impaired functioning is likely to present a high-risk mental state for development of clinically important psychotic disorders such as schizophrenia, and indeed such individuals are amongst the targets for early intervention services. Our broad aim is to understand more about how these high-risk mental states for psychosis arise during adolescence in order to inform future preventive interventions.

Our first two aims are to describe the extent of these high risk mental states and their relationship with earlier mental health problems, such as depression, anxiety, conduct problems as well as earlier psychotic symptoms. We will then look at two areas that appear to be very important for the aetiology of psychosis. The first of these is the consistent association found between people who have lower IQ scores and the development of psychosis. The second is the relationship between cannabis use and the later development of these high risk mental states. There is extensive and repeated data available on these matters in the Avon Longitudinal Study of Parents and Children (ALSPAC) and the study will be able to exploit the previously collected data in order to answer these questions.

Technical Summary

The presence of psychotic symptoms with concurrent impaired functioning is likely to present a high-risk mental state for development of clinical psychotic disorders such as schizophrenia, and indeed such individuals are amongst the targets for early intervention services. Our broad aim is to understand more about how these high-risk mental states for psychosis arise during adolescence in order to inform future preventive interventions. More specifically our aims are as follows:

Aim 1: To estimate the prevalence of a high-risk mental state for psychosis at age 17, as defined by psychotic symptoms with concurrent impairment in social, educational, or occupational functioning.

Aim 2: To examine the continuities and discontinuities between psychopathology in childhood and early-mid adolescence and high-risk mental states at age 17.

Aim 3: To investigate the hypothesis that decline in IQ between 8 and 15 years is associated with the development of a high-risk mental state by age 17, independently of other psychopathology.

Aim 4: To investigate the hypothesis that cannabis use during adolescence is associated with development of a high-risk mental state by age 17, independently of confounding factors and reverse causation effects. We will also test the hypothesis that early use of cannabis confers an increased risk of a high risk mental state. We will examine gene-environment interplay between cannabis use and genetic variation within a number of candidate genes for psychosis including the reported interaction with variation within COMT.

In order to achieve these aims we will conduct an interview-based assessment of psychotic symptoms in a population-based sample of 17-year old adolescents within the ALSPAC cohort, and assess the impact of these symptoms on social, educational and occupational functioning from personal, parental and educational reports.

Publications

10 25 50

 
Description MRC Project grant
Amount £872,123 (GBP)
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start 09/2010 
End 03/2013
 
Description GENDEP 
Organisation King's College London
Department Institute of Psychiatry, Psychology & Neuroscience
Country United Kingdom 
Sector Academic/University 
PI Contribution This study and mine used very similar methods allowing joint use of the data for genetic analysis.
Collaborator Contribution They have contributed data and also led the analysis on one paper.
Impact Publications that are included
Start Year 2011
 
Description Psychiatric Genetics Consortium 
Organisation King's College London
Department Institute of Psychiatry, Psychology & Neuroscience
Country United Kingdom 
Sector Academic/University 
PI Contribution Via links with IOP have contributed to the PGC
Collaborator Contribution They coordinate large GWAS studies on psychiatric disorders
Impact Publication as listed
Start Year 2012
 
Description University of Bristol Twilight Talk 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact The university invited members of the public to a set of informal discussion topics concerned with the Children of the 90s (ALSPAC) study.

It was successful and there are plans to repeat this for ALSPAC members.
Year(s) Of Engagement Activity 2010