Well-designed evaluations of psychological interventions on psychiatric intensive care units (PICUs) are a rarity.

To evaluate the effectiveness of cognitive behaviour therapy for intrusive taboo thoughts with a patient diagnosed with bipolar affective disorder admitted to a PICU due to significant ongoing risk of harm to self.

This was a four-phase ABC plus community follow-up (D) mixed methods n=1 single case experimental design. Four idiographic measures were collected daily across four phases; the baseline (A) was during PICU admission, the first treatment phase (B) was behavioural on the PICU, the second treatment phase (C) was cognitive on an acute ward and the follow-up phase (D) was conducted in the community. Four nomothetic measures were taken on admission, on discharge from the PICU, discharge from the acute ward and then at 4-week follow-up. The participant was also interviewed at follow-up using the Change Interview.

Compared with baseline, the behavioural and the cognitive interventions appeared effective in terms of improving calmness, optimism and rumination, but the effects on sociability were poor. There was evidence across idiographic and nomothetic outcomes of a relapse during the follow-up phase in the community. Eleven idiographic changes were reported in the interview and these tended to be unexpected, related to the therapy and personally important.

Single case methods can be responsive to tracking the progress of patients moving through in-patient pathways and differing modules of evidence-based interventions. There is a real need to implement robust outcome methodologies on PICUs to better evaluate the psychological aspects of care in this context.