Online Social Networking and Mental Health
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183915/
"Addiction to online social networking, as well as Internet addiction in general, are recent and insufficiently investigated phenomena, frequently discussed and sometimes disputed in the psychiatric literature.30–35 The addictive nature of SNS is supported primarily by the mental preoccupation of many chronic SNS users who as a result tend to neglect other aspects of their social functioning such as family and offline friends. In addition, according to our own observations, sudden cessation of online social networking (i.e., lack of Internet connection) may in some chronic users cause signs and symptoms that at least partially resemble the ones seen during drug/alcohol/nicotine abstinence syndrome."
And just googling "facebook addiction nih", it looks like there is plenty more material of this sort.