People at high risk for psychosis access primary care mental health services for depression and anxiety and are unlikely to recover from these affective symptoms. We report the first controlled trial of cognitive–behavioural therapy (CBT) for depression and anxiety, minimally adapted for psychosis risk, in primary care.

To evaluate feasibility, acceptability and signals of efficacy for CBT for depression and anxiety adapted for psychosis risk, designed in collaboration with people with psychosis.

A longitudinal controlled trial comparing best practice CBT for depression and anxiety (CBT-BP) with CBT adapted for psychosis risk (CBT-PR), in patients meeting criteria for UK primary care services and who are also clinically high risk for psychosis (trial registration no. ISRCTN40678).

Rates of recruitment (55 to CBT-BP, 44 to CBT-PR), completion of measures (90% CBT-BP, 94% CBT-PR) and retention in therapy (75% CBT-BP, 95% CBT-PR) demonstrate the feasibility and acceptability of the adapted therapy. Routine measures of depression and anxiety signal improved clinical and recovery outcomes for CBT-PR. Psychosis and relational measures signal sustained improvement (at 3 months) in the CBT-PR group. No serious adverse events were reported.

Primary care mental health services present a unique opportunity to identify and treat people at risk of psychosis at a time when they are help-seeking. CBT for depression and anxiety, minimally adapted for psychosis risk, can be delivered in routine services, and is likely to improve clinical and recovery outcomes and reduce psychosis risk. A definitive trial is needed to estimate clinical and cost-effectiveness.