Investigating the impact and underpinnings of complex post-traumatic stress disorder in people with schizophrenia spectrum disorders.

Schizophrenia spectrum disorders (also known as 'psychosis') are severe mental health diagnoses characterised by symptoms like hallucinations and delusions. These disorders typically incur a high disability. Many people with psychosis are affected by trauma, and show symptoms of post-traumatic stress disorder (PTSD), such as flashbacks or anxiety. These people struggle more with their symptoms, and have a worse prognosis. Recently, clinicians have classified a subset of people who experience traditional PTSD symptoms, as well as other symptoms, like problems feeling close to others or regulating their emotions. This is referred to as complex PTSD (CPTSD), and is often associated with multiple traumas in early life. We know that people with CPTSD struggle with more difficulties than those with PTSD, but we don't know how people with schizophrenia spectrum disorders might be affected by the disorder. For instance, CPTSD could maintain distressing psychotic symptoms. We also know that CPTSD might need different treatments than PTSD, and so people with schizophrenia spectrum conditions and CPTSD might need more specialist, targeted treatments than those with schizophrenia alone.

Therefore, this project aims to explore the relationship between CPTSD and schizophrenia spectrum conditions, examine the impact of CPTSD on outcomes in people with psychosis, and investigate whether CPTSD symptoms maintain psychotic symptoms. In my first study, I will bring together the research in the area, to understand what we already know about CPTSD and schizophrenia spectrum disorders (e.g., how common this comorbidity is). In my second study, I will analyse data collected from an ongoing randomised controlled trial. I will compare people with schizophrenia alone, people with schizophrenia and PTSD, and people with schizophrenia and CPTSD to assess whether and how their symptoms might differ and interact with one another. For example, some symptoms, like flashbacks, might make some people hear voices. In my third study, I will ask people from these groups to download an app on their phone that will prompt them to complete questionnaires throughout the day. These questionnaires will measure the symptoms of psychosis, PTSD and CPTSD. This will allow me to look at how these might symptoms influence each other and how this affects people in daily life.

The project will improve the understanding of how complex trauma could affect outcomes among people with schizophrenia spectrum disorders. This could lead to clinicians assessing for symptoms of CPTSD among people with psychosis, and develop targeted therapies for this group. Understanding whether and how CPTSD symptoms maintain psychosis could also develop a basis for future research to investigate how CPTSD might predispose people to develop psychosis.