Psychological Medicine

Original Articles

Outreach and Support in South London (OASIS). Outcomes of non-attenders to a service for people at high risk of psychosis: the case for a more assertive approach to assessment

C. E. L. Greena1 c1, P. K. McGuirea1, M. Ashwortha2 and L. R. Valmaggiaa1

a1 King's College London, King's Health Partners, Institute of Psychiatry, Department of Psychosis Studies, and Outreach and Support in South London (OASIS), South London and Maudsley NHS Trust, London, UK

a2 King's College London, King's Health Partners, Department of Primary Care & Public Health Sciences, London, UK


Background International agreement dictates that clients must be help-seeking before any assessment or intervention can be implemented by an ‘at-risk service’. Little is known about individuals who decline input. This study aimed to define the size of the unengaged population of an ‘at-risk service’, to compare this group to those who did engage in terms of sociodemographic and clinical features and to assess the clinical outcomes of those who did not engage with the service.

Method Groups were compared using data collected routinely as part of the service's clinical protocol. Data on service use and psychopathology since referral to Outreach and Support in South London (OASIS) were collected indirectly from clients' general practitioners (GPs) and by screening electronic patient notes held by the local Mental Health Trust.

Results Over one-fifth (n=91, 21.2%) of those referred did not attend or engage with the service. Approximately half of this group subsequently received a diagnosis of mental illness. A diagnosis of psychosis was given to 22.6%. Nearly 70% presented to other mental health services. There were no demographic differences, except that those who engaged with the service were more likely to be employed.

Conclusions Over one-fifth of those referred to services for people at high risk of psychosis do not attend or engage. However, many of this group require mental health care, and a substantial proportion has, or will later develop, psychosis. A more assertive approach to assessing individuals who are at high risk of psychosis but fail to engage may be indicated.

(Received September 07 2009)

(Revised March 08 2010)

(Accepted March 11 2010)

(Online publication April 21 2010)


c1 Address for correspondence: Dr C. E. L. Green, OASIS, PO 67, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. (Email: