Treatment trials for negative symptoms in schizophrenia

Negative symptoms in schizophrenia remain an unmet treatment need. Recent guidelines and meta-analyses suggest that some pharmacological and psychosocial interventions show modest efficacy. Adding to this evidence, this review summarizes randomized clinical trials (RCTs) published between January 2024 and October 2025 on pharmacological, psychosocial, physical, digital, and neuromodulatory interventions targeting negative symptoms.

Most recent RCTs were small and methodologically heterogeneous, and effects on negative symptoms were generally modest. Exercise-based and body-oriented interventions, CBT-based interventions, psychosocial programmes, and digital tools were feasible and often associated with within-group improvement, but rarely superior to active controls or treatment as usual; only a larger yoga trial showed clear added benefit. Cognitive remediation did not directly reduce negative symptoms, but recent work indicates that negative symptoms moderate the translation of cognitive gains into functional improvement. Pharmacological trials yielded mixed results, with signals for muscarinic agonist-antagonist treatment, selected repurposed agents, and sulforaphane. Neuromodulation studies, particularly intermittent theta burst stimulation and transcutaneous auricular vagus nerve stimulation, suggested small to moderate improvements that depended on stimulation parameters and treatment duration.

Current evidence confirms that negative symptoms are modifiable and underscores the need for adequately powered, mechanism-informed, multimodal trials with long-term follow-up.