Bouldering intervention: therapy manual

Bouldering is defined as rock climbing to moderate heights (up to around four metres) without rope. Boulder Gyms offer a great number of routes that vary in difficulty levels (often marked by different colours). People of different fitness levels can therefore easily boulder together in the same group without being underchallenged or overstrained. Our newly developed bouldering therapy consisted of eight consecutive weekly sessions of three hours each from ten a.m. to one p.m. An average of 12 to 13 people attended each therapy group at a time, and each session was supervised by two therapists. Each session began with a short meditation or mindfulness exercise; thereafter, the subject of the specific session was given, followed by a short psychoeducation on this subject (for example: How to cope with anxiety). The session proceeded with subject-related bouldering games or exercises. Participants were encouraged to engage in new experiences (for example, bouldering blindfolded). After a break, the last part of the session consisted of free bouldering by which participants in small groups worked on their individual projects supported by the therapists. Each session ended with another mindfulness meditation and a gathering about what was experienced and how this could be integrated into daily life. Table 1 provides an overview of the sessions and their topics. The therapists were mental health therapists (psychologists or registered nurses with a specific psychiatric qualification) who had undergone training in “Therapeutic rock climbing” at the Austrian “Institute for Therapeutic rock climbing” (www.therapieklettern.com). One of the therapists in each session was a climbing instructor certified by the German Alpine Association. The therapists also had several years of climbing experience themselves.

Table 1 Session overview and subjects Full size table

Methods of evaluation

Design

The study was conducted as a randomised waitlist-controlled pilot study with an intervention period of 8 weeks. After the initial assessment, the intervention group began with the bouldering therapy. After 8 weeks, the groups changed, and the intervention was provided to the waitlist group, while the intervention group returned to their individual treatments that were not influenced by the study. The measurement points consisted of a baseline measure (t0) and measures taken after 8 weeks (t1), 16 weeks (t2), and 24 weeks (t3). See Fig. 1 for the study design. The ethical committee of the Friedrich-Alexander University Erlangen-Nuremberg approved the study design (Re.-No. 99_13 B).

Recruitment and randomisation

Participants were recruited for the study in four different ways: In the two psychiatric hospitals in Erlangen, informational material was laid out and contact details were given so that either the participants or their physicians could apply for study participation. In addition, the same informational material was sent to all psychotherapists in town and also to other services that provide care for people with depression, such as self-help groups or other initiatives. Furthermore, nonbinding informational events were announced in newspapers and via the Internet so that any interested people could participate. Interested participants were informed about the study by the therapists in a face-to-face meeting and provided written consent. They were randomly assigned to one of the two groups: intervention or waitlist. We computer generated a randomisation list for each group at t0 (Treatment group1 (T1) and Waitlist group 1 (W1) together and groups T2 and W2 together; see Consort Flow Chart Fig. 2), assigning half of the participants to the treatment group and the other half to the waitlist group. In some cases, randomisation was not possible because the maximum number of participants had been reached in a group; in a few cases, if a participant was not available on more than two Thursday mornings in one of the two eight-week periods, he or she was assigned to the other time period. Baseline data were collected from all participants, including the WHO screening test on depression (WHO-5 www.who-5.org).

Fig. 2 Consort flow chart Full size image

Inclusion and exclusion criteria

The inclusion criteria consisted of either a diagnosis of depression by a psychiatrist or less than 13 points on the WHO depression scale [24], informed consent, and having free time on Thursday mornings during the intervention period. Exclusion criteria consisted of undergoing in-patient treatment during either the intervention or the waiting periods, acute suicidality or psychosis, or a strong medical contraindication against sport, determined by a GP or psychiatrist.

Instruments

In the beginning, participants completed a questionnaire to collect the following information: age, gender, educational level, employment status, current medication, current psychotherapy, BMI, and experience with rock climbing or bouldering. The participants were also asked to use a 4-point scale (ranging from agree completely to disagree completely) to rate whether they had respect for bouldering and if they slept well at night. In addition, the WHO questionnaire on well-being (www.who-5.org), a short screening tool for depression, was administered to determine participants’ current level of depression and subsequent inclusion in the program.

The BDI-II [25, 26] is a widely used instrument that is designed to measure the intensity of depression experienced during the past two weeks. The BDI-II contains 21 specific symptoms of depression with answer options that consist of four increasing levels of severity, ranging from zero to three. The total score is the sum of all responses, which can range from zero to 63. Scores ranging from zero to 13 indicate minimal depressive symptoms, scores of 14 to 19 represent mild depression, scores of 20 to 28 indicate moderate depression, and scores of 29 or above represent severe depression.

The Symptom-Checklist SCL-90-R [27, 28] is a self-report inventory that is used to examine the global intensity of psychological symptoms and distress experienced during the past seven days using a five-point Likert-type scale ranging from zero to four. The SCL-90-R covers nine symptom dimensions, including depression and anxiety. Ratings are summed for each subscale with higher scores indicating an increasing severity of symptoms.

The FERUS is a widely applied instrument designed to measure individuals’ health-related resources and manageability [29]. Its 66 items comprise seven scales, including subscales that measure self-efficacy, coping, and self-verbalisation. Items are rated on a 5-point Likert scale that ranges from one to five, with higher test scores indicating better resources and manageability skills.

The d2-R, a paper-pencil test consisting of 14 lines with 57 characters each, was administered to measure participants’ attention and concentration performance [30]. Individuals were instructed to discriminate between similar visual stimuli by crossing out target objects (d with two lines) while ignoring other characters (p or d with no, less than two, or more than two lines). Scores provided by the d2-R include concentration performance (CP), percentage of errors (E %), fluctuation rate (FR), as well as the total number of items processed minus errors (TN-E).

Statistical analyses

The analyses were carried out with SPSS 21.0. Descriptive methods were used for the sample description and the presentation of the results (frequencies, percentages, means, and standard deviations). First, we computed difference scores as the difference between t1 and t0. These difference scores (i.e. change scores over the intervention period for the intervention group versus over the waiting period for the waitlist group) were compared with a two-sample T-Test (after checking for homogeneity of variance). As a sensitivity analysis, U-Tests were also computed. Cohen’s d was calculated as a measure of effect size. For the main outcome criterion (depression measured with the BDI-II), a regression analysis was computed with age, sex, medication (antidepressants yes or no), psychotherapy, depression severity, and group as predictors. In addition, the Number Needed To Treat was calculated. An improvement in the BDI-II of more than 6 points was defined as a clinically relevant threshold. This reflects an improvement of about one severity grade. Secondary outcomes were viewed as exploratory.