Teenagers spending more time on social networking sites like Facebook and Twitter are prone to develop narcissistic tendencies, psychological disorders and anti social behaviors, according to a study.

Larry Rosen, a professor of psychology at California State University conducted a study to observe the impact of social media on human interaction and he says daily overuse of media and technology has a negative effect on health of all children, preteens and teenagers making them susceptible to anxiety depression and other psychological disorders.

Some of the symptoms of these effects would be:

* Increased absence from school and likelihood of developing stomach aches, sleeping problems, anxiety and depression, in teens who “overdose” in technology on a daily basis, including Facebook and video games;

* Lower grades for middle school, high school and college students who checked Facebook at least once during a 15-minute study period;

* Lower reading retention rates for students who most frequently had Facebook open on their computers during the 15-minute study period.

An earlier report from Baroness Greenfield, professor of pharmacology at Oxford University, suggests, excess use of social networking sites are turning people self obsessed, craving for attention like a baby saying, “Look at me, Mummy, I've done this.”

She believes the excessive use of social networking platforms and video games could ‘rewire’ the brain.

However, Rosen’s research also points at a positive impact that social network can have — Young adults who spend more time on Facebook are better at showing "virtual empathy" to their online friends.