A psychotic-like experience in itself does not confer a specific enough risk in regards to clinically relevant psychosis (4). However, it has been shown that the co-occurrence of hallucinations and delusions increases the risk of subsequent clinical outcomes. The temporal ordering of the occurrence and co-occurrence of specific psychotic-like symptoms has not been examined. This project also aims to establish the association between particular patterns of occurrence and co-occurrence with established risk factors such as a family history of mental illness, substance use, and childhood victimisation. There are three interconnected parts to the analysis which correspond to intended paper publications.

Demographics of developmental trajectories of psychosis

(1) Do homogeneous patterns of psychotic-like symptoms exist for responses at 11.6, 13, 14, and 16.5 years via the PLIKS questionnaire?

(2) Are parental histories of mental illness and substance use disorder, adverse events during pregnancy, and socio-economic variables able to predict 'stayers' and 'movers' in the latent transition model?

Trauma-based antecedents of the developmental trajectories of psychosis

While controlling for previously identified demographic confounders:

(1) When adjusting for IQ and early childhood psychotic disorders, do childhood adversities (such as bullying, death of relative or friend, and emotional cruelty) predict transition?

(2) When adjusting for IQ, early childhood psychotic disorders and childhood adversities, do parental childhood adversities (up to the age of 17) predict transition?

(3) Are there significant associations with any of the transitions when entering time-varying exposure variables into the model, such as social skills, substance use, schizotypy, attachment and moods?

Outcomes and risk profiles for the developmental trajectories of psychosis

(1) What sort of outcomes are associated with specific transitions?

References

1. Bebbington P, Jonas S, Kuipers E, King M, Cooper C, Brugha T, et al. Childhood sexual abuse and psychosis: data from a cross-sectional national psychiatric survey in England. The British journal of psychiatry?: the journal of mental science [Internet]. 2011 Jul [cited 2011 Oct 26];199:29-37. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21508437

2. Johns LC, Cannon M, Singleton N, Murray RM, Farrell M, Brugha T, et al. Prevalence and correlates of self-reported psychotic symptoms in the British population. The British journal of psychiatry?: the journal of mental science [Internet]. 2004 Oct [cited 2011 Nov 17];185:298-305. Available from: http://www.ncbi.nlm.nih.gov/pubmed/15458989

3. Bendall S, Jackson HJ, Hulbert C a, McGorry PD. Childhood trauma and psychotic disorders: a systematic, critical review of the evidence. Schizophrenia bulletin [Internet]. 2008 May [cited 2011 Aug 7];34(3):568-79. Available from: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2632421&tool=p...

4. Linscott RJ, van Os J. Systematic reviews of categorical versus continuum models in psychosis: evidence for discontinuous subpopulations underlying a psychometric continuum. Implications for DSM-V, DSM-VI, and DSM-VII. Annual review of clinical psychology [Internet]. 2010 Apr 27 [cited 2011 Aug 23];6:391-419. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20192792

5. Wigman JTW, van Winkel R, Raaijmakers Q a W, Ormel J, Verhulst FC, Reijneveld S a, et al. Evidence for a persistent, environment-dependent and deteriorating subtype of subclinical psychotic experiences: a 6-year longitudinal general population study. Psychological medicine [Internet]. 2011 Nov [cited 2011 Oct 27];41(11):2317-29. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21477418