Ethical approval and consent to participate

The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2013.
The study was registered at the Internet Portal of the German Clinical Trials Register (DRKS; registration number: DRKS00016538). Ethical approval was granted by the IRB of the University of Vienna (reference numbers 00356 and 00445). Furthermore, we obtained a Universal Trial Number (UTN) to facilitate the unambiguous identification of our trial (UTN: U1111-1226-3285).
Clinical psychologists explained the study to participants prior to their participation at the baseline assessment using an information sheet (German and Dari versions) with the help of an interpreter. Participants who agreed to participate gave written informed consent.