All residents of the Gaza strip and West Bank's Nablus district were eligible for free-cost treatment in the MSF program. Patients were identified by an active case finding, through a local mental health and counseling network, the Mental Health Initiative. This network is a collaboration between local and international NGOs, the Palestinian counseling center, the Palestinian Ministry of Health, and United Nations agencies. Only patients, aged more than one year, with a psychological disorder potentially related to a traumatic event were included in the MSF program. Patients with psychiatric chronic diseases or with only medical issues were excluded and referred to one of the two psychiatric hospitals of the Palestinian Ministry of health, for specific care.
For each patient included, a clinical evaluation was done by a psychologist or a psychiatrist, using a semi-structured interview based on criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) . Under the supervision of the senior MSF psychologist/psychiatrist, each evaluator was trained to complete a standardized and validated questionnaire. In case of psychopathological troubles, specific psychological care, consisting of individual, group, or dyad therapy [13, 14], at home or in a consultation center, was offered. At the end of the treatment, or at the last visit, the condition of the patient was evaluated by a quantitative categorical analysis and classified in four categories (aggravated, unchanged, improved or cured). This classification was based on the number of symptoms and their severity in comparison with the initial evaluation.
Data were collected using a standardized questionnaire about sociodemographic characteristics (age, gender, geographic location (residence)), clinical features (patient-reported complaints, symptom type and severity, main and associated diagnostics identified per DSM-IV-TR), self-reported exposures to lifetime adverse events (frequency and type of traumatic event, family violence, chronic disease, history of psychiatric illness) and proposed psychological care (short-term psychotherapy type, length, and outcome). All patient information was entered anonymously, and oral informed consent was obtained before administration of the questionnaire.
Clinical and epidemiological data were entered into an EpiData database (EpiData, Odense, Denmark). Data for this study represent a secondary data source from which a descriptive analysis was performed. Therefore, no sample size or power calculation were performed since the analysis was conducted within the context of an existing cohort and the "sample" represented all patients enrolled in the program. Descriptive and statistical analyses were performed by age group (children ≤ 15 years old versus adults >15 years old), gender, and geographical area (Nablus district versus Gaza strip), using Epi Info version 6 (Centers for Disease Control and Prevention, Atlanta, GA, USA). Proportions or means were compared respectively by Chi-square test and independent samples t-test, with 5% significance level.