BackgroundProblematic Internet use (i.e., Internet use that disrupts functioning in other important domains; PIU) is increasingly prevalent worldwide, particularly among youth. One form of PIU relates specifically to interpersonal interaction and communication, deemed social PIU. Social PIU has been linked to various forms of psychopathology, including attention-deficit/hyperactivity disorder (ADHD). Yet with limited longitudinal research, the direction of this association remains unclear. Moreover, little research investigates whether social PIU is linked to one or both symptom dimensions of ADHD (inattention vs. hyperactivity/impulsivity).MethodsThe present study utilized data from the largest extant longitudinal study of girls with childhood-diagnosed ADHD (N = 228). Linear regression and structural equation models were used to analyze social PIU as both a prospective predictor and outcome of ADHD symptoms.ResultsInattentive ADHD symptoms were positively associated with concurrent social PIU in initial regression models but were non-significant in path analyses. Social PIU was only marginally significant in predicting subsequent inattention six years later. Symptoms of hyperactivity/impulsivity were unrelated to social PIU among girls at either time point.ConclusionsInattentive ADHD symptoms were initially positively linked to concurrent problems with social Internet use, but bidirectional associations were non-significant in path analyses. Relations between PIU and ADHD in girls may be less robust than previously thought, although further longitudinal research with clinical samples is needed to clarify which groups of adolescents are particularly vulnerable to social PIU and its long-term effects.