I think the whole 'chicken or egg?' question comes into play here.
My sister had Asperger's Syndrome and was also a computer game addict. But that doesn't mean to say that the condition (or perhaps even false diagnosis if you believe the article) was brought on by her addiction; it's just as (more) likely that her intensive game playing was a result of her condition. She was reclusive and often uncomfortable in social situations which meant that the added 'barrier' of communicating over the internet made her feel more comfortable.
Don't forget that while Asperger's and suchlike are mental conditions, they can manifest themselves in physical ways. Sufferers typically can't pick up on body language and suchlike very well (and conversely often give off the 'wrong signals' themselves). But none of those things matter when you are sat behind a computer monitor - there is no eye contact, no speech inclination, jokes are typically highlighted (smilies etc).... so many of the communication disadvantages these people face in everyday life are diluted or dissolved.