The Efficacy and Effectiveness of Online CBT - Jeroen Ruwaard

3.2. Method 413.2.2 ParticipantsEnrollment. The recruitment procedure, which targeted people from the generalpopulation with mild to moderate depression, started with the publication of an articlein a national Dutch newspaper announcing the study. The article referred readers toa website, which provided psycho-education regarding depression and its treatment,explained the purpose and design of the study, and contained an application form.Screening. Respondents were screened by means of web-administered self-reportquestionnaires. The following exclusion criteria were applied: a score less than10 (no depression) or more than 29 (severe depression) on the Beck DepressionInventory (BDI-IA: Beck, Ward, Mendelson, Mock, & Erbaugh, 1961; Beck et al., 1979),age under 18 years, heightened risk of dissociation or psychosis, suicidal ideation,drug and alcohol abuse, use of neuroleptic medication, unstable dosages of otherpsychiatric medication, concurrent psychotherapy, high anxiety levels, or a prevailingposttraumatic stress disorder or panic disorder. Finally, eligible respondents wererequired to download, print, and return a signed Informed Consent form. Respondentswith severe depression (BDI-IA>29) were referred to a concurrent clinical trial of aface-to-face treatment for severe depression (Dekker et al., 2007). Other excludedrespondents were referred to their GPs or received information concerning mentalhealth centres in their vicinity.Risk of dissociation was assessed using the five-item Somatoform DissociationQuestionnaire (SDQ-5; Nijenhuis1997), using a cut-off of 8. Respondents who scoredabove this cut-off also completed the longer, more specific Dissociation-Questionnaire(DIS-Q; Nijenhuis, Spinhoven, van Dyck, van der Hart, & Vanderlinden, 1998).Risk of psychosis was attributed to respondents who scored above the cut-off valueof 5 on the Hallucination scale of the Screening Device for Psychotic Disorder (SDPD;Lange, Schrieken, et al., 2000). Suicidal ideation was measured using an inventorysimilar to that of Joiner et al. (2003). Respondents with suicidal plans or a history ofrecent suicide attempts (within the past 3 years) were excluded. High anxiety levelswere detected using the Anxiety and Stress subscales of the Depression Anxiety StressScales (described below in the Outcome Measures section). Prevailing posttraumaticstress or panic disorder was inferred in respondents who either scored higher than