Research performed by psychologists from Edinburgh Napier University indicated that Facebook adds stress to users' lives. Causes of stress included fear of missing important social information, fear of offending contacts, discomfort or guilt from rejecting user requests or deleting unwanted contacts or being unfriended or blocked by Facebook friends or other users, the displeasure of having friend requests rejected or ignored, the pressure to be entertaining, criticism or intimidation from other Facebook users, and having to use appropriate etiquette for different types of friends. Many people who started using Facebook for positive purposes or with positive expectations have found that the website has negatively impacted their lives.
Next to that, the increasing number of messages and social relationships embedded in SNS also increases the amount of social information demanding a reaction from SNS users. Consequently SNS users perceive they are giving too much social support to other SNS friends. This dark side of SNS usage is called ‘social overload’. It is caused by the extent of usage, number of friends, subjective social support norms, and type of relationship (online-only vs offline friends) while age has only an indirect effect. The psychological and behavioral consequences of social overload include perceptions of SNS exhaustion, low user satisfaction, and high intentions to reduce or stop using SNS