Social networking sites (SNSs) are now used by billions of users worldwide and can help facilitate communication and the sharing of information. However, there is evidence that problematic SNS use (PSNSU) can have negative effects on health. The present study examined the associations between PSNSU, sleep quality, attention-deficit/hyperactivity disorder (ADHD), depression, anxiety and stress among SNS users. A total of 638 SNS users (mean age = 32.03 years, SD = 10.08) completed an online survey comprising instruments assessing SNS addiction, sleep quality, ADHD, depression, anxiety and stress. Regression analysis indicated that the factors of age (β = − .24, p < .01), relationship status (i.e., being in a relationship) (β = − .09, p < .05), ADHD (β = .43, p < .01) and anxiety (β = .12, p < .01) explained 23.9% of the variance in problematic SNS use. Bivariate correlations identified moderate positive correlations between PSNSU, poor