People suffering from severe affective disorders generally have poor prognosis and ‘Affektivt Team’ in Southern Denmark offers specialised outpatient follow-up treatment. Against the advice of professionals many patients choose not to participate in the group-based parts of this treatment. Purpose: The aim of this qualitative interview study was to gain insight into the patients’ personal motives for choosing, or not choosing, group-based psychotherapy. Seventeen patients were interviewed using a semi-structured interview guide. The interviews were transcribed verbatim and analysed thematically. Results: The findings are summarised in two central themes: 1. Models of illness and expectations to treatment. 2. Benefits and psychosocial experiences from the groups. The trustworthiness and limitations of the findings are discussed. Conclusions: The respondents primarily conceived treatment as medicine combined with individual psychotherapy and saw groups as social events – not as psychotherapy. For that reason group-based therapy is not an obvious choice of treatment.