Data analysis: Data will be analysed in SPSS and presented descriptively in the two Groups to show whether the randomisation succeeded. A "intention to treat" analysis will be conducted, and on the basis of a requisite analysis a t-test, Mann-Whitney-Wilcoxon test or chi2-test will be used. The association between predictive factors and response to wake therapy will be described with prevalence proportions, ratios and will be analysed with a chi2-test. The level of statistical significance will be set at 5 %. The randomisation will be computer-generated, and the patients will be randomly allocated to the intervention group or the control group.