Substance use and addictive disorders are among the most significant public health concerns, particularly during adolescence. The current study aims to investigate internet gaming disorder, social media addiction, and loneliness levels in adolescents and youths with substance use. The study group consisted of 93 adolescents and youths aged 15-24 who presented to the Alcohol and Substance Addiction Research and Application Center or the Child and Adolescent Mental Health and Diseases outpatient clinic for substance use. Ninety-one healthy volunteers who did not use substances during any period of their lives participated as a control group. The participants fulfilled the Social Media Addiction Scale (SMAS), Internet Gaming Disorder Scale - Short-Form (IGDS9-SF), UCLA Loneliness Scale (UCLA-LS), and Drug Use Disorders Identification Test - Extended (DUDIT-E). The symptoms of internet gaming disorder were significantly lower in the patient group compared with the control group. Although it was not significant, social media addiction was higher in the patient group than in the control group. The experience of loneliness was significantly higher in the patient group than in the control group. A significant negative correlation was found between treatment motivation and loneliness. School guidance teachers should monitor children who do not have friends or are lonely and be aware of the potential for substance use because it can emerge as a method of coping with the feeling of loneliness among adolescents. In future studies, investigating comprehensive factors contributing to different addictive behaviors may help to clarify the co-occurrence.