The current cross-sectional study sought to determine the mental health problems of adolescents with mild intellectual disability (ID) and influencing factors. This study, which used a comparison group, was performed with 188 adolescents (91 with mild ID and 97 without ID) between January 2019 and June 2019 in Turkey. Data were collected using a Personal Information Form, the Strengths and Difficulties Questionnaire, Pittsburgh Sleep Quality Index, and Perceived Social Support Scale. Adolescents with mild ID were at higher risk for mental health problems compared to those without ID. According to linear regression analysis, sex, age, birth order, maternal age, parents' educational level, sleep quality, and perceived social support were statistically significant predictive factors of mental health problems in adolescents with mild ID. Results of this study indicate that adolescents with mild ID are at greater risk for mental health problems and that effective prevention/intervention strategies are needed. [
Journal of Psychosocial Nursing and Mental Health Services, xx
(xx), xx–xx.]