There is emerging evidence that SNS use can lead to lower well-being. However, at the theoretical level our understanding of the mechanisms that explain the relationship between SNS and wellbeing is still limited in important ways. In order to better understand adaptive as well as maladaptive use of SNS, we need to examine cognitive-motivational mechanisms that drive SNS use. Based on the current state-of-the-art, several cognitive motivational mechanisms related to self-determination and identity development can be linked to SNS use. In addition, it is also crucial to get a better understanding about the individual characteristics that may reflect an increased vulnerability for psychological problems as a consequence of social media use.