Measures

Only participants who completed the treatment programme as planned wrote a farewell letter as part of a ritual at the end of treatment. At the start and end of treatment, the Symptom Check List 90 (SCL-90) [20] was completed.

As part of the farewell ritual, the farewell letter is read to group members, treatment staff and one or two important persons outside of the treatment. No writing instruction was given, but the participants were familiar with the farewell letters of former group members. This familiarity meant that certain standard components appeared in most of the letters. All farewell letters were kept in folders accessible to the patients.

The authorized Dutch version of the SCL-90 [21] is a questionnaire with 90 questions; it uses a 5-point rating scale ranging from 1 (‘not at all’) to 5 (extreme response). The questionnaire assesses general psychological distress and specific primary psychological symptoms of distress during the last week. Outcome scores are divided into nine symptom subscales: anxiety, agoraphobia, depression, somatization, insufficient thinking and handling, distrust and interpersonal sensitivity, hostility, sleeping disorders, and rest. The total score (range 90–450) is calculated by adding the scores of the subscales. The test–retest reliability has been shown to be fair to good (k = .62–.91) [21].