Bus Beheading: Was Li on or off his meds?

I know that Penny has been doing a bang up job on covering the utterly tragic Bus beheading incident, where Tim Mclean was ruthlessly murdered by Li.

What has really bugged me about this event, was the early mention of drugs then nothing since. It was revealed that Li had a history of mental illness. My question - Was Li on prescribed pharmaceuticals at the time of the murder? Or had he recently stoppped taking his meds? I ask this because it has been documented that withdrawl of SSRIs can result in suicidal/violent outbreaks and can often lead to bizarre and maccabre murders or murder suicides.

Just take a look at this database.

So, was the drug angle dropped because it a) Wasn't an 'illegal' drug which influenced Li? b) Could prove embarrassing to the makers of the 'pharmacuetical' medicine? c) both of the above.

My take: Li went off his meds and flipped out. The resulting shitstorm (if the public was aware) would spark outcry from the public about what kind of mind altering crap the 'hellth' authorities are allowing folks to be pumped up on. Hence - no more mention in the press about any kind of 'drug' influencing Li's behaviour.

Don't know about you, dear readers, but just skimming the above database certainly lends credence to the hypothesis that Li was messed up on legal drugs.