Mental health and studies...

I am a uni student now and because it is a medical university there are often studies from higher students because of some works or their doctorate.
But there's almost always required to not take medication (except for birth control).

So, now there's a new study about chocolate and there are only two requirements:
• age between 18-something (I don't know)
• no psychiatric illness ...

I just hate that. I can never participate in these things, but all of my friends can. Because they don't take medication and they are not mental.

I mean if I didn't have depression I couldn't participate because of my blood disease - where I have to take medication - and because being trans* is a mental thing.

Thanks.

Also you mostly get paid for that.