Adolescence is a transitional phase that brings many psychological and physiological challenges that increase emotional vulnerability and threaten the adolescent's mental well-being. Indeed, mental illnesses, such as depression and eating disorders, show an alarming increase in prevalence after puberty. Adolescent depression is particularly concerning owing to the fact that it is a principal cause of disability among adolescents, an important risk factor for suicidality, and is associated with higher risks of present and subsequent morbidity. Our study aimed at (1) examining the psychometric properties of the Patient Health Questionnaire–9 (PHQ-9) and (2) evaluating the correlation between depression, eating disorders, stress, and other variables in a sample of Lebanese adolescents.

This cross-sectional research enlisted 555 Lebanese teenagers (15–18 years) from all Lebanese governorates (May–June 2020). The confirmatory factor analysis of the PHQ-9 scale items was carried out using the SPSS AMOS program v.24. The relative chi-square, the root mean square error of approximation (RMSEA), Tucker Lewis Index (TLI) and the comparative fit index (CFI) were all utilized as goodness-of-fit indexes.

The median age of the participants was 16.66 ± 1.00 years, with 75.7% females. Among these 555 adolescents, 62.9% had mild-to-moderate depression and 14% reported moderately severe-to-severe depression, while only 23.1% were classified as not suffering from depression. Confirmatory factor analysis of the PHQ-9 scale was conducted using the one-factor structure that is described in the literature; the fit indices obtained were acceptable as follows: χ²/df= 136.26/27 =5.05, CFI=0.92, TLI=0.90 and RMSEA=0.085 [0.072–0.100]. However, the modification indices between items 6 and 9 were high; after correlating these two items, the fit indices improved more as follows: χ²/df= 105.59/26=4.06, CFI=0.94, TLI=0.92 and RMSEA=0.074 [0.060–0.089]. The multivariable analysis results showed that more stress (β=0.59), female sex (β=1.54), and more binge eating (β=0.16) were significantly associated with more depression.

This study supports the validity of the PHQ-9, which presents as a reliable tool for the evaluation of depression in future epidemiological studies of Lebanese adolescents. It also elucidates the high level of depression among this age group and its correlation with modifiable and unmodifiable factors.