Professor Stanley Zammit

Professor Stanley Zammit

Professor of Psychiatric Epidemiology, Division of Psychological Medicine and Clinical Neurosciences

School of Medicine

+44(0) 29 2068 8435
Media commentator

I hold a joint appointment as Professor of Psychiatric Epidemiology across Cardiff University and the University of Bristol

My main research interest is studying the epidemiology of psychiatric disorders, especially psychosis. I am particularly interested in the following areas of research:

  1. The relationship between cannabis use and risk of developing psychotic disorders
  2. The genetic epidemiology of schizophrenia, including the study of gene-environment interactions
  3. The development and life course trajectory of psychotic experiences in the general population
  4. The role of modifiable cognitive processes in the aetiology of psychosis
  5. The role of psychological trauma on incidence of psychosis, and impact of trauma-focused interventions in treating and preventing psychosis

Professional memberships

1998: Member of the Royal College of Psychiatrists

My research aims to increase understanding of the aetiology of schizophrenia and other psychotic disorders, and improve treatment outcomes for people with such disorders. My research interests include:

1)    Lifecourse epidemiology: I am interested in understanding the development of psychotic experiences, persistence of symptoms, symptom trajectories, and transition to psychotic disorder from childhood through older adulthood. I aim to apply rigorous methodology to examine the role of aetiological factors, operating prenatally through to adulthood, on development of specific symptoms of psychosis, and to understand the pathways mediating causal relationships. The aetiological factors we are examining include genetic variation, prenatal nutrient deficiency and exposure to infection, neurocognitive development, social cognition, social relationships, substance use, trauma and adversity, and the wider social environment.

2)    Translation from clinical samples into the general population: I am interested in studying the likely population impact of key findings from clinical samples, for example, how genetic risk for schizophrenia, as determined by cutting-edge findings from collaborative GWA studies, is manifest phenotypically during childhood in the population, and whether this changes during adolescence and adulthood. We are also studying the overlap in genetic and non-genetic factors between psychosis and other disorders, particularly autism spectrum disorders, depression and anxiety.

3)    Biomarkers and cognitive markers for psychosis: We are studying the use of genetic, epigenetic, proteomic, neuroimaging and cognitive data to help inform prediction for incident psychotic experiences and transition to clinical disorder to inform early intervention approaches. I am particularly interested in the predictive role of cognitive processes such as reasoning biases and errors in predictive processing that can help bridge the gap between biological abnormalities observed in psychosis and experiences of psychotic phenomena.

4)    Psychosis and trauma: As a result of my clinical work in the Cardiff Traumatic Stress Service, I am very interested in the overlap between psychosis, post-traumatic stress disorder and borderline personality disorder, and the common role of trauma in these disorders. We are examining the role of potentially modifiable cognitive processes mediating the impact of trauma on psychotic and quasi-psychotic experiences. Ultimately, our aim is to develop interventions to reduce trauma-related symptoms in people with psychotic disorders and related psychopathology.

The core aim of my research is to apply robust methodology to epidemiological data, and utilise causal analysis methods such as use of negative controls and Mendelian Randomisation approaches to inform causal inference. I am experienced in using epidemiological data from a number of population-based cohort studies, particularly the Avon Longitudinal study of Parents and Children (ALSPAC) and Swedish record-linkage datasets.

My research involves strong collaborations with colleagues at Cardiff University, University of Bristol, and other academic institutions across the UK and internationally, particularly the Karolinska Institute in Sweden.

Areas of expertise

External profiles