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OASIS: ten years of early intervention

Since its inception, a decade ago, OASIS (Outreach and Support in South London) has become one of the world’s largest early intervention services for people at high risk of psychosis. 

The service was created by researchers at the Institute of Psychiatry at King’s College London and clinicians at the South London and Maudsley NHS Foundation Trust (SLAM), and pioneered the integration of research and clinical practice. The model was a forerunner to that adopted by the Psychosis Clinical Academic Group, within King’s Health Partners Academic Health Sciences Centre

Psychosis is a syndrome that includes delusions, hallucinations and confused and disturbed thinking, and is evident in disorders like schizophrenia and bipolar disorder. Some patients recover from an episode of psychosis with minimal symptoms, but for others psychosis can be persistent and affect their ability to lead a well life. Prevention of psychosis has become one of the major objectives in psychiatry and is the focus of much research. 

To mark the 10 years of OASIS, Professor Philip McGuire, Head of the Department for Psychosis Studies at the IoP at King’s and Clinical Director of OASIS and colleagues lay out the successes and challenges in a paper published in European Psychiatry

Professor McGuire says: “OASIS was a very early example of the huge benefits that come from integrating research and clinical practice. The idea of intervening in the high-risk group, before the first episode of psychosis was a novel clinical area, so research in the field was relatively scarce. We designed the service in a way that facilitated research in this area. 

“The focus of our research was informed by what we witnessed in the clinic, and we were able to use findings from our research to improve our clinical practice. There was a real synergy between clinical and research activity, which allowed us to develop an excellent clinical service and carry out cutting edge research.”

Treatment at OASIS:

The OASIS team currently covers a wide urban area in South London (Lewisham, Croydon, Lambeth and Southwark), which has one of the highest rates of psychosis in the UK. 

The Ultra High Risk state is characterized by the presence of attenuated psychotic symptoms, which often occur in the context of a recent decline in social and occupational functioning. Individuals are referred by a range of professional,  community and family sources, and are usually seen in the individual’s GP surgery. Up to 30% of people at Ultra High Risk will develop a psychotic disorder within 2 years, and OASIS provides clinical support for 2 years. The aims of the service are to help people at Ultra High Risk with their presenting problems, and to reduce the risk of later psychosis.

Research at OASIS:

OASIS has provided a platform for an extensive research programme, including work on genetics, epidemiology, psychopathology, cognitive function, and neuroimaging. These research studies have provided new information on the psychosocial and neurobiological factors that influence the development of psychosis, and have informed the development of new treatments for the ultra high risk stage. 

Professor McGuire says: “The challenge now is to find predictors of later transition to psychosis. It’s difficult to distinguish who will go on to develop psychosis from who will not at the behavioural level. We are trying to identify biological markers that can differentiate patients according to their future clinical outcome. For example, the chemistry, function and structure of the brain in people who later develop psychosis appears to be different from that of people who do not. We want to develop tools that allow clinicians to use this kind of information to tailor clinical care to the needs of the individual patient.”

For example, researchers at King’s Institute of Psychiatry are developing ways of quantifying the risk of transition for individuals classed as high-risk by developing algorithms based on genetic, neuroimaging and cognitive data to identify a sub-set of individual at high-risk who will later develop schizophrenia. By using data from the high-risk OASIS group, researchers are also hoping to gain new insights into the neuro-biological changes that happen as the individual transitions to psychosis. 

For full paper: Fusar-Poli, P. et al. ‘Outreach and support in South London (OASIS), 2001-2011: ten years of early diagnosis and treatment for your individuals at clinical high risk for psychosis’ European Psychiatry doi: 10.1016/j.eurpsy.2012.08.002

For further information about psychosis, please visit 

For further information, please contact Seil Collins, Press Officer, Institute of Psychiatry, King’s College London. Email: or tel: 0207 848 5377