The emersion of the Internet did not only change human communication and information seeking, it also contributed to manifold alterations in the manifestation, perception and treatment of mental disorders. Thus, one focus of current psychological research lies on the relationship between the new medium and psychosocial functioning. This review embraces recent results on this topic following a discussion from two different perspectives: first, it poses the question, whether the Internet - due to its very specific character - is capable of creating new mental disorders and second, it asks whether rare disorders may possibly be uncovered by the Internet or if already known disorders may be sustained and intensified by the online medium. Accordingly, the first part of this review deals with the conceptual basis of problematic Internet use, Internet addiction and problematic online-gaming as an example of specific internet use. Predisposing psychosocial factors, such as social isolation, depression and compulsive behavior are reviewed as potential triggers for these new internet- related disorders. The second part however draws upon two already existing groups of psychological disorders: eating disorders in relation to Pro-Ana and Pro-Mia on the one hand and Body Integrity Identity Disorder (BIID) on the other hand. Recent research is discussed to explore the sustaining and intensifying effect of the Internet on these disorders.