Illuminating a joyless life: a transdiagnostic approach to anhedonia.

This transdiagnostic programme of work will examine the mechanisms underlying a reduced experience of pleasure (anhedonia) using novel methods which harness the latest developments in structural equation modelling, mobile health monitoring and virtual reality. Anhedonia is a significant barrier to recovery in mental health conditions in two conditions; psychosis and depression, with no effective interventions targeting anhedonia recommended by NICE. Similarities in the experience of anhedonia in these two groups have been proposed but not tested. This body of work will begin with qualitative interviews to understand the experience of these difficulties first-hand, for the first time. Machine learning techniques will be applied to identify maladaptive patterns in affect and detect vulnerable moments where intervention would be impactful. Experience sampling methodology (ESM) with a smartphone app will then examine the strongest candidate mechanisms from the depression literature: negative thinking patterns and reduced attention in positive experiences, across diagnostic boundaries. Candidate mechanisms will be tested in the final study using novel, ecologically valid virtual reality scenarios. This bold programme of research will advance the field with a transdiagnostic model of anhedonia, a step change in our understanding of an under-researched but critical area in recovery.