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Student thesis: Doctoral ThesisDoctor of Philosophy

Introduction Psychotic disorders are known for their wide variability in clinical and social outcomes beginning from illness onset and throughout their course. Our current lack of understanding of the origins for this heterogeneity is further compounded by dearth in knowledge on how patients come to the attention of mental health services and methodological incongruity across different studies. Employing samples of first episode psychosis (FEP) patients, the aims of this thesis were to: 1) look back on the pathways to care patients used to enter mental health services and the use of prodromal services in South London; and 2) examine trajectories of the psychotic disorders and potential predictors of their longitudinal outcomes. Methods Two large samples of patients with FEP (i.e., GAP and EU-GEI) were utilised in this thesis. For the study 1, information on pathways to care undertaken prior to coming to generic services for FEP was extracted from the Biomedical Research Centre (BRC) Case Register Interactive Search (CRIS) system. For studies 2, 3 and 4, using electronic clinical records, extensive information in three domains-clinical, social and service uses-was collated over 4-5 years after contact with mental health services. Results Only a small fraction of individuals (4.1%) who present with FEP to the main secondary mental health provider have previously been in contact with prodromal services and made a subsequent transition to psychotic disorder; 77% this sub-group of patients entered their pathway to care via referral from General Practice or other health professional. In contrast, 45% of FEP group without prior contact with the prodromal services made first contact with mental health services via emergency services and 18% of this group were referred by the criminal justice system. Further, combining the baseline schizophrenia diagnosis with five symptom dimensions (i.e., positive, negative, excited, disorganised/concrete and depressed dimensions) generated the best model fit for predicting time to first remission. During the 5-year follow up after first contact with mental health services, a higher proportion of Black African and Black Caribbean ethnicity had compulsory re-admissions and instances of police involvement during an admission to a psychiatric unit compared with White British ethnic group. Patients of Black African and Black Caribbean ethnicity did not differ from White British ethnic group in overall functional disability and illness severity, or frequency of remission or recovery during the follow up period. However, patients of Black ethnicity become increasing socially excluded as their illness progress. In a sample of first-episode schizophrenia spectrum patients, 35% of the sample met the criteria for treatment resistance (TR) at the end of the first 5 years of follow up. Of these TR patients, 70% of these were treatment resistant from illness onset. Those who subsequently developed TR were more likely to have an early illness onset (<20 years) compared to those with non-TR. The relationship between an early age of onset (<20 years) and TR was specific to patients of Black ethnicity and patients of male gender. Conclusions Very few of those who come to FEP services come after being seen for an at-risk-mental state by prodromal services suggesting that the scope for reducing or delaying onset of psychosis by this means may still be limited. My results indicate that supplementing the baseline categorical schizophrenia diagnosis with ratings on five symptom dimensions improves the prediction of delayed treatment response as measured by time to first remission. Further, the longitudinal trajectory of psychosis in patients of Black ethnicity did not show greater clinical or functional deterioration than white patients. However, their course remains characterised by more compulsion, and longer periods of admission. Finally, I showed that for the majority of the TR group, lack of response to antipsychotic treatment is present from illness onset, necessitating a consideration for an earlier use of clozapine.
Original languageEnglish
Awarding Institution
Award date2017


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