Psychological Interventions for Complex PTSD And Schizophrenia-Spectrum Disorder: PICASSO Trial

BACKGROUND & RATIONALE FOR STUDY

Psychosis, characterised by unusual experiences such as delusions and hallucinations, is commonly associated with a diagnosis of schizophrenia. It affects up to 3% of the population, and individuals with this condition often experience high levels of distress, a loss of ability to plan and work, and a loss of interpersonal relationships. People with psychosis die 15-20 years earlier than the general population, however existing treatments for psychosis have at best modest effects on symptoms and related distress. Consequently, many thousands of people are left with highly distressing symptoms that remain resistant to current treatment.

Exposure to childhood trauma substantially increases the risk of developing psychosis. Post-traumatic stress disorder (PTSD) and psychosis frequently co-occur and PTSD is a known risk factor for later psychosis. However, strategies to treat PTSD in psychosis have had limited success. This may be because psychosis overlaps with a more complex condition than PTSD, namely Complex PTSD (CPTSD). CPTSD, now recognised in the 11th revision of the World Health Organisation's International Classification of Diseases (ICD-11), is defined as PTSD (i.e. intrusive thoughts, avoidance of reminders of the traumatic memory and hyperarousal) and co-occurring symptoms of affect dysregulation (AD), negative self-concept (NSC), and disturbed relationships (DR). These symptom domains, which are commonly referred to as Disturbances of Self-Organisation (DSO), are also highly prevalent in psychosis, and they appear to mediate the relationship between childhood adversity and psychotic symptoms. In a recent pilot study (n=85), 41% of people with psychosis endorsed symptoms of CPTSD, confirming that CPTSD and psychosis very frequently co-occur. Thus, psychological treatments that reduce CPTSD symptoms might represent a new direction in both the conceptualisation and treatment of psychosis.

Although there is strong observational evidence that traumatic stress may cause psychosis via CPTSD symptoms, this relationship has not been tested experimentally. Furthermore, although there are existing psychological interventions for CPTSD symptoms, it is unknown whether they are effective at reducing psychotic symptoms. Based on an established effective therapy for complex traumatisation (Skills Training in Affective and Interpersonal Regulation; STAIR), the investigators have recently devised a treatment protocol for CPTSD (Enhanced STAIR for CPTSD - ESTAIR with three 6-session modules targeting individual DSO symptom clusters of CPTSD (AR, NSC & DR). The next stage of our research will focus on whether targeting DSO symptoms in people with psychosis can improve treatments for psychosis. The investigators will examine the feasibility of conducting an 'Umbrella trial' to test whether CPTSD symptoms are causally related to psychosis, and develop more effective trauma-focused psychological interventions for psychosis. This involves running three single-blind 'interventionist-causal' randomised controlled trials (IC-RCTs) concurrently, each testing whether an individual ESTAIR DSO module (addressing either AD, NSC or DR) causes improvements in psychotic symptoms. Recommended to accelerate the treatment of psychotic symptoms such as delusions, running these sophisticated trials concurrently can produce significant findings 10-15 years earlier compared to running each trial individually. If the feasibility of this Umbrella trial can be established, defined as successful recruitment and retention of participants with psychosis, the investigators will seek funding to conduct a definitive trial.

AIMS and RESEARCH QUESTIONS