Background: The use of antipsychotics in primary care is increasing, and more are being used for non-psychotic illnesses. Long-term use of antipsychotics confers increased risk of cardiometabolic disease, so ongoing need should be reviewed regularly by psychiatrists. This study explored changes over time in antipsychotic management and prescribing in primary care, and proportions of patients (≥18 years) prescribed antipsychotics receiving psychiatrist review. Methods and Findings: This was a retrospective, population-based observational study using data from the Secure Anonymised Information Linkage databank of approximately 3 million people in Wales (2011 to 2020). Outcomes were prevalence of patients who had received ≥6 antipsychotic prescriptions per year, proportion of patients prescribed antipsychotics who had received psychiatrist review in the preceding 12 months, and proportion of patients prescribed antipsychotics who were registered on the UK Primary Care Serious Mental Illness, Depression and/or Dementia registers, or were not on these registers. The prevalence of adults prescribed antipsychotics increased from 1.06% (95%CI 1.04 to 1.07%) in 2011 to 1.45% (95%CI 1.43 to 1.46%) in 2020; 1 in 69 adults were prescribed antipsychotics in 2020. The proportion of adults taking antipsychotics solely managed by primary care increased from 40% (95%CI 39 to 41%) in 2011 to 48% (95%CI 47 to 49%) by 2020. The proportion of antipsychotics prescribed to patients not on the Serious Mental Illness register increased from 50% (95%CI 49 to 51%) in 2011 to 56% (95%CI 56 to 57%) by 2020, meaning many patients may not be monitored for the cardiometabolic risk from antipsychotics. Conclusions: Antipsychotic prescribing is increasing. More people are solely managed by general practitioners without psychiatrist review and are not on relevant disease registers, so are less are likely to undergo vital cardiometabolic monitoring. These trends pose risks for patients and need to be addressed urgently.

AW, LEW, IB, and FSM receive funding from the NIHR DynAIRx project(NIHR 203986) investigating the use of artificial intelligence to optimize prescribing. IB has acted as an advisor to Astrazeneca plc, on behalf of University of Liverpool.

AW was awarded an Health Care Research Wales Research Time Award (Grant number: NHS-RTA-21-02) to undertake this work.

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SAIL Databank Information Governance Research Panel (of Swansea University, Wales, UK) gave ethical approval for this work.

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