Abstract Background At this moment, there are more refugees than ever before. Refugees have more chance of developing psychopathology, which can be explained from the (biosocial) ecological models....Show moreAbstract Background At this moment, there are more refugees than ever before. Refugees have more chance of developing psychopathology, which can be explained from the (biosocial) ecological models. Individual and environmental traits influence the development, course and treatment of psychopathology. An unstable environment might cause more stress and mental health issues. The aim of this meta-analysis is to research how effective psychotherapy is for treating PTSD in refugees, and if age as individual factor and language/ cultural adaptation as environmental factor influence the treatment efficacy. Methodology A systematic review with different meta-analyses. Results Systematic researches provided 132 effect sizes within 80 suitable studies. The overall effect size of treating PTSD was significant (Cohen’s d = -0.941, p < 0.001). There were no significant differences between the mean effect sizes of treating PTSD between children, adolescents and adults. There was no difference in treatment efficacy as a function of the level of language or cultural adaptation found. Discussion and conclusion These results show that psychotherapy significantly lowers PTSD symptoms in refugees. However, our results do not find evidence for the proposed (biosocial) ecological models since age and adaptation are not associated with treatment efficacy. Moreover, there is a large difference in treatment efficacy between refugees and non-refugees, this might be caused by the different structural designs between the studies included in this meta-analysis. Future research should consider these different structural designs and should research more environmental factors that can increase treatment efficacy.Show less
