This behavior is often linked to growing feelings of social withdrawal and a loss of a sense of being fully alive.

CNN: Can schoolyard bullying lead to PTSD?

The symptoms of vicarious trauma -- stress, social withdrawal, sensitization to televised violence -- are not enough to make people violent themselves, said Barbara Rothbaum, director of the Trauma and Anxiety Recovery Program at Emory Medical School.

CNN: Treating trauma victims may cause its own trauma

His new emphasis on Europe, which also includes restoring the opt-out from the social chapter, withdrawal from the European People's party, opposing the constitution and keeping the pound, is clearly aimed at Euro doubters in the country as much as his party critics.

BBC: Analysis