BACKGROUND: The negative symptoms of schizophrenia are strongly associated with functional disability and reduced quality of life yet remain among the least effectively treated symptoms. Existing pharmacological and psychosocial recommendations show only modest empirical support and limited implementation in routine care. A growing number of psychosocial interventions have been developed to target specific mechanisms underlying negative symptoms, but the evidence base has not been mapped. METHODS: A scoping review was conducted following PRISMA guidelines to identify studies testing psychosocial interventions explicitly targeting negative symptoms or their theorised mechanisms in adults with a schizophrenia-spectrum diagnosis. Study characteristics, intervention targets and tools, and negative symptom outcomes were synthetised narratively. RESULTS: Thirty-one studies including RCTs (k = 18), pilot studies (k = 8), case series (k = 3), and other designs met the inclusion criteria. Interventions targeted >25 mechanisms, most commonly motivation, defeatist beliefs, activity levels, social communication, and expressive difficulties. Most studies (k = 23) reported positive effects on negative symptoms, though effects were often not sustained at follow-up and outcome measures varied widely. Several theoretically grounded approaches-such as behavioural activation, CBT-based interventions, positive-emotion focused, and emerging digital or VR-supported therapies-showed promising but very preliminary evidence. CONCLUSIONS: There are targeted psychosocial interventions for the negative symptoms of schizophrenia showing promising results despite methodological limitations. Encouragingly many of these interventions seem to adopt a mechanistic approach, with specific adaptations to support engagement and effectiveness in this population. These interventions urgently need further optimisation and testing in large, rigorous randomised controlled trials to support wider implementation.
Edwards et al. (Sat,) studied this question.