Background Problematic internet use (PIU) is an increasingly worrisome issue, as youth population studies are establishing links with internalizing and externalizing problems. There is a need for a better understanding of psychiatric diagnostic profiles associated with this issue, as well as its unique contributions to impairment. Here, we leveraged the ongoing, large-scale Child Mind Institute Healthy Brain Network, a transdiagnostic self-referred, community sample of children and adolescents (ages 5-21), to examine the associations between PIU and psychopathology, general impairment, physical health and sleep disturbances.Methods A total sample of 564 (190 female) participants between the ages of 7-15 (mean = 10.80, SD = 2.16), along with their parents/guardians, completed diagnostic interviews with clinicians, answered a myriad of self-report questionnaires, and underwent physical testing as part of the Healthy Brain Network protocol.Results PIU was positively associated with depressive disorders (aOR = 2.34; CI: 1.18-4.56; p = .01), the combined subtype of ADHD (aOR = 1.79; CI: 1.08-2.98; p = .02), greater levels of impairment (Standardized Beta = 4.79; CI: 3.21-6.37; p < .01) and increased sleep disturbances (Standardized Beta = 3.01; CI: 0.58-5.45; p = .02), even when accounting for demographic covariates and psychiatric comorbidity.Conclusions The association between PIU and psychopathology, as well as its impact on impairment and sleep disturbances, highlight the urgent need to gain an understanding of mechanisms in order to inform public health recommendations on internet use in U.S. youth.