Efficacy aims
There were four inter-related efficacy aims. The first was to determine the extent to which treatment in the form of a suicide-focused cognitive–behavioural intervention for people with psychosis (CBSPp) would be more effective in reducing suicidal thoughts compared to a control group (TAU alone) over 6 months. Accordingly, it was predicted that suicidal thoughts would be less severe in the treatment group (CBSPp intervention plus TAU) compared to the control group (TAU alone) at 6 months relative to baseline.
The related second efficacy aim was to examine the acceptability of the suicide-focused therapy, CBSPp, to participants. The third was to investigate the barriers and facilitators to implementing CBSPp in NHS mental health services from the perspectives of participants and mental health professionals working in the NHS. Both of these aims were addressed using qualitative methods and analyses.
The final efficacy aim was to determine the extent to which any reductions in suicidal thoughts in the treatment group would endure when tested at a 12-month follow-up period.
Mechanism aims
There were two mechanism aims. The first was to test the extent to which the treatment group (CBSPp plus TAU) would reduce negative appraisals of social support, emotional processing, interpersonal problem-solving and also reduce perceptions of defeat, entrapment and hopelessness. It was expected that reductions in these six negative appraisals would be greater in the treatment compared to the control group and that these reductions would, in turn, be associated with less-severe suicidal thoughts across 6 months compared to the control group. In other words, the six negative appraisals would act as mediators, and the effect of treatment would act, at least in part, via these mediators.
The second mechanistic aim used qualitative methods to explore the pathways underpinning suicidal experiences from the participant’s perspectives of living with psychosis and suicidal experiences.
Clinical aims
There were two clinical aims. The first was to gain information about therapy process variables, including session number; formulation; engagement with, and adherence to, CBSPp therapy; and the therapeutic alliance.
The second clinical aim was to determine the extent to which participating in a research project which was focused on suicidal thoughts and behaviours would result in negative experiences and negative emotional reactions. This aim was addressed using convergent qualitative and quantitative mixed methods.
Exploratory aim
An exploratory aim was to examine health economic variables within the trial, namely estimates of mental health and social care resource use in each arm.