The relationship between computer-mediated communication (e.g., Internet or social media use) and mental health has been a long-standing issue of debate. Various disciplines (e.g., communication, psychology, sociology, medicine) investigate computer-mediated communication in relation to a great variety of negative (i.e., psychopathology) and positive (i.e., well-being) markers of mental health. We aim at charting this vast, highly fragmented, and fast growing literature by means of a scoping review. Using methods of computational content analysis in conjunction with qualitative analyses, we map 20 years of research based on 1,780 study abstracts retrieved through a systematic database search. Results reveal the most common topics investigated in the field, as well as its disciplinary boundaries. Our review further highlights emerging trends in the literature and points to unique implications for how future research should address the various relationships between computer-mediated communication and mental health.