Table 2. Inclusion and Exclusion Criteria.

Inclusion

Exclusion

Staff outcomes included skills relevant to psychological practice (e.g. communication, formulation) Staff were adults Peer-reviewed Qualitative, mixed, or quantitative studies (e.g. reviews, trials, or RCTs) If filtering was available, studies were listed under an educational/training heading Patient outcomes Articles in English, Polish, Greek, Punjabi, or Spanisha

Quantitative studies without comparison data (outcome pre- and/or post-intervention, or control group) Insufficient description to replicate programme delivery (e.g. length of intervention, time between sessions, etc.) Full text cannot be found Papers written in a language not understood by the reviewers Intervention was not delivered to healthcare staff Studies on non-human subjects Developmental studies (e.g. childhood or ageing studies) Skills irrelevant to psychological practice in an adult mental healthcare setting were taught

^aLanguages understood by reviewers.