CAS usually develops as a person gets older but can occur from as early as birth.
It is believed to be linked to the following:
Fucking Awful Hollywood Movies
TV Shows such as X-Factor, I'm a Celebrity, Big Brother and Jersey/Geordie Shore
TV Soap Operas
Having your heart stamped on by an ex-partner
PTD (Post Travel Depression)
Having shitty parents
CAS is infectious and can spread to other people. Infection becomes more likely to those that spend alot of time with a current CAS sufferer.
In extreme cases CAS can develop into Gothic Syndrome