OASIS – National preventive unit for psychosis and bipolar risk

Innovative early detection and assessment for young people at risk

The OASIS service constitutes the UK’s largest NHS hybrid preventive mental health model, addressing the early stages preceding the onset of psychosis and bipolar disorders in young individuals aged 14 to 35. Designed in collaboration with South London and Maudsley NHS Foundation Trust, this model is:

• Aligned with NICE guidelines, the NHS Long Term Plan, and Mental Health Implementation Plan

• Inclusive, non-stigmatising, and community-oriented

• Supported by a robust evidence base, demonstrating clinical and cost-effectiveness

• Tailored and bespoke assessments of mental vulnerabilities and preventive recommendations

The OASIS service delivers a cutting-edge assessment of emerging psychosis and bipolar states through bespoke psychometric assessment and a comprehensive report, along with personalised clinical recommendations for preventive care. The assessment offered by OASIS will fill the unmet need of many young people who may be at risk of developing psychosis or bipolar disorders and who largely remain undetected. Most of these young people seek help at primary care surgeries or other mental health Trusts which lack capacity to offer a fast-tracking assessment. These assessments are grounded in clinical evidence, guided by national policy, and adaptable to individual needs. From expert diagnostic reviews and standardised risk assessments to scalable recommendations, the service provides a flexible and cost-effective approach to preventive care, designed to enhance outcomes and reduce progression to severe mental illness.

Expert clinical review

This component enables diagnostic consultation and strategic overview of implementation challenges for preventive psychiatry. It provides:

• a detailed evaluation of existing clinical documentation to support early identification and diagnostic clarity during the early stages of psychosis and bipolar

• second-opinion reviews by experienced clinicians with a longstanding track record of early detection and prevention of psychosis and bipolar

• strategic and operational input and supervision for implementing new preventive service models

The expert clinical review process supports primary and secondary care providers in making evidence-informed decisions.

Psychometric assessment for psychosis or bipolar risk

This component enables accurate identification of at-risk mental states to inform preventive care. It provides:

• a comprehensive assessment for psychosis and bipolar risk using validated psychometric tools such as the Comprehensive Assessment of At Risk Mental State (CAARMS), the Semistructured Interview of Bipolar At Risk States (SIBARS) and other tools

• a detailed clinical report, including a personalised risk profile to inform ongoing care

Scalable preventive interventions

Preventive interventions are not currently offered by OASIS but are under planning for the next phases.

Referral access and eligibility

OASIS accepts referrals from across the UK, including NHS primary care, secondary care services, and Integrated Care Boards (ICBs). While assessments are delivered by the OASIS team, clinical responsibility remains with the referring service. The initial pilot will support up to 15 individuals, with capacity expected to expand as part of future service development.

Evidence-based outcomes

The OASIS model has demonstrated significant clinical benefits, including a 59% reduction in transition to psychosis (RR 0.41), a marked reduction in hospital admissions and compulsory treatment, and a shorter duration of untreated illness. These outcomes not only improve patient trajectories but also alleviate pressure on acute mental health services. The service has recently expanded preventive approaches to bipolar disorders. The service has been recognised for its excellence through national awards and clinical impact studies.

Academic and financial sustainability

With over 10,000 academic citations and approximately £50 million in grant income secured over the past decade, OASIS represents a clinically robust and financially sustainable approach to early mental health intervention. The model has proven to be cost-effective and capable of generating income to support service continuity within the NHS framework.

National workforce development

Supported by £813,227 in NHS England funding (2022–2026), the OASIS team has co-developed a national CAARMS training programme to enhance workforce capacity in psychosis and bipolar risk assessment. Delivered in collaboration with Maudsley Learning, this package is now available commercially across the UK and Europe, supporting clinical excellence and consistent care delivery through standardised training pathways.

Pilot implementation and service launch

The OASIS national pilot will be formally launched at the Maudsley Learning Conference in April 2025. The initial 12-month pilot phase (April 2025 – March 2026) will evaluate service outcomes, inform future scaling, and establish streamlined governance and coordination processes across stakeholders. Key learnings from the pilot will inform future commissioning and wider adoption across the NHS.