According to a recent report having lots of Facebook friends can make you stressed.

Stress arises when a user presents a version of themself on Facebook that is unacceptable to some of their online 'friends', such as posts displaying behavior such as swearing, recklessness, drinking and smoking.
As older people join the site, this has become an increasing problem as their expectations may be very different from those of younger users, the report said.
Researchers found that on average people are Facebook friends with seven different social circles.
The report, which, surveyed over 300 people on Facebook, also discovered that more people are Facebook friends with their former partners than with their current relationship partner. Only 56 per cent of users were friends with their boyfriend, girlfriend or spouse online, compared with 64 per cent of exes.
Source-ANI