The subject was a 20-year-old male inmate serving a 15- month sentence following a breach of probation order. He had 11 previous convictions, with a previous 1-year custodial sentence. During his 1-year sentence, the subject became depressed, refused to come out of his cell, refused food, and completed his sentence in the prison's hospital wing following a suicide attempt. Recognizing the pressure of both cost and time factors, it was decided to pilot Barkham's 2+1 format in the prison setting. After baseline information had been obtained, the first clinical session assessed current difficulties and formulated a problem list. The subject was introduced to the cognitive-behavioral model, and links between mood and activity were discussed. The second session was more cognitive in orientation, while the third session was devoted to a review of the earlier sessions. Baseline measures were readministered 1 month after the intervention to see if any changes had been sustained. These measures included the States of Anxiety and Depression Questionnaire, the Beck Depression Inventory, and the Locus of Control of Behavior. The psychological intervention using the 2+1 formula was therapeutically effective. Over the course of the three sessions, significant reductions were observed in measures of depression, together with a corresponding increase in perceived self-efficacy. It was determined that depression in prisons can be treated with cognitive-behavioral techniques and that the 2+1 format may be an appropriate model to investigate in more detail. 31 references, 1 table, and 1 figure