This was a cross-sectional study in which three hundred and fifty-two children and adolescents with any cancer diagnosis were screened for depression using the Child Depression Inventory (CDI) and evaluated with the mini neuropsychiatric interview for children and adolescents (MINI-KID). Associated factors were assessed using a standardized questionnaire that assessed child and caregiver demographic and psychosocial characteristics. Multiple logistic regression models were used to assess factors independently associated with MDD.
The diagnosis of MDD is confirmed using the MINI during the screening visit. The MINI is a widely used structured diagnostic interview which enables clinicians to make diagnoses of psychiatric disorder [50, 51]. It is a clinician-administered questionnaire divided into modules corresponding to diagnostic categories (MDD, suicidality, bipolar disorder, panic disorder, agoraphobia, social phobia, obsessive-compulsive disorder, post-traumatic stress disorder, alcohol dependence/abuse, substance dependence/abuse, psychotic disorder and mood disorder with psychotic features, anorexia nervosa, bulimia nervosa, generalised anxiety disorder, antisocial personality disorder). The diagnosis of MDD is confirmed if participants experience five or more of nine symptoms (depressed mood, loss of interest, significant weight loss or gain or decrease or increase in appetite, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue or loss or energy, feelings of worthlessness or excessive or inappropriate guilt, diminished ability to think or concentrate or indecisiveness, recurrent thoughts of death or recurrent suicidal ideation without a specific plan or suicide attempt or a specific plan) including depressed mood or loss of interest.
Food consumption was assessed using a food frequency questionnaire (FFQ), developed by Schneider et al.  and validated for teenagers in São Luís . The FFQ collected information on food intake during the 12 months prior to interviews. Food intake was evaluated and grouped according to the NOVA degree of processing classification: culinary preparations (unprocessed or minimally processed foods, and processed culinary ingredients), processed, and ultra-processed culinary ingredients [percentage of caloric participation] .
On the other hand, this study also has strengths. The main strength was the extensive training of the team of interviewers, performed to reduce the biases during data collection. Another strong point was the construction and use of DAG to identify confounding factors, which indicated the minimum set of variables for adjustment, seeking to avoid inadequate or unnecessary adjustments.
This cross-sectional study was conducted at the campus of the Hellenic Military School of Combat Support Officers (Greek Spelling: Stratiotiki Scholi Axiomatikon Somaton, SSAS) in Thessaloniki, Greece, in March 2013. Briefly, military medicine cadets complete a 6-year long medical curriculum provided by the Aristotle University of Thessaloniki Faculty of Medicine. In addition, they reside within the campus of SSAS, where they receive intense military training in the form of basic combat training, compulsory military courses and an introduction to military life and discipline. All candidates applying to the Hellenic military academies are pre-screened before admission for major psychiatric conditions. The psychiatric assessment of each candidate includes the administration of psychometric instruments such as the Symptom Checklist- 90- R and the Minnesota Multiphasic Personality Inventory (MMPI) followed by an interview conducted by a psychiatrist and a psychologist; candidates with an active Axis I (DSM-IV) pathology, including current depression or a personality disorder (Axis II), are excluded from service. History of depressive episodes when disclosed by the candidate is also a criterion for exclusion.
Multiple studies have investigated the prevalence of depressive symptoms in non-medical military trainees. For example, a cross-sectional study employing the self-rating depression scale (SDS) revealed a higher mean depression score in a cohort of 466 Chinese soldiers who had just completed their initial recruit training, compared to the general population . In another study by Iversen et al.  the Patient Health Questionnaire 9 was administered via telephone interview in a sample of UK military personnel drawn from the phase 1 KCMHR military health study, half of whom were deployed during the active phase of the 2003 Iraq War; in that cohort the prevalence of any depressive syndrome and major depressive syndrome was 11 and 3.7 %, respectively. Moreover, in another cross-sectional study using the SDS, Xiong et al.  reported a depression rate of 25.2 % during field military training in a random sample of 1,220 Chinese soldiers. In that study, higher education level, shorter military service, origin from a city or town and health problems during military training were associated with depressive symptoms.
Diagnoses of mental disorders were established using the Greek version 5.0.0 of the Mini International Neuropsychiatric Interview (MINI) . The MINI is a structured psychiatric interview that ascertains the diagnosis of mental disorders according to DSM-IV or ICD-10 criteria . It focuses mainly on current diagnosis and contains 120 questions for screening 17 axis I disorders. Being fully structured to allow administration by clinicians after a brief training session, it was designed to meet the need for a short but valid psychiatric interview for epidemiology studies . MINI has been previously used in studies with Greek medical patients [22,23]. 1e1e36bf2d