Re-examining mental health crisis intervention: A rapid review comparing outcomes across police, co-responder and non-police models

Police are the default first responders in most mental health crisis intervention models worldwide, resulting in a heavy burden on police, perceived criminalization of individuals with complex mental health needs, and escalation of aggression that resort to violence. Models, such as crisis intervention teams (CIT), and co-response programmes aim to improve service user experiences and outcomes by providing mental health training to police, or pairing law enforcement officers with mental health clinicians, respectively. Despite these efforts, mental health-related calls continue to result in negative outcomes, and activists and policymakers are advocating for non-police models of crisis intervention. Evidence-based practice in mental health crisis intervention is urgently needed. The present review's main objective was to examine, synthesise and compare outcomes across police, co-responder and non-police models of mental health crisis intervention internationally using a rapid review framework. A systematic search of four electronic databases of studies published between 2010-2020 and a grey literature search was conducted, yielding (n = 1008) articles. A total of 62 articles were included in the present review. Studies were largely observational, lacking control groups and were of low-moderate quality with a high potential for bias. Overall, there is little evidence to suggest that the CIT model impacts crisis outcomes. Co-responder models evidenced improved outcomes compared to police only models, however, evidence was often mixed. Non-police models varied significantly, and studies tended to be too low quality to make comparisons or draw conclusions, however, research on youth models and crisis resolution home treatment suggested positive outcomes. Findings highlight the need for high-quality studies and policies to facilitate the implementation and evaluation of novel approaches not involving police. Cross-sectorial collaboration and service user input are urgently needed to inform, develop, test and disseminate effective models of crisis intervention acceptable to service users.