In my family, we have some drunks.
None are mental. So, maybe not most - I will agree to "A lot".
Anchorage is now going thru a *bit* of a problem with thousands of 'homeless' that is costing the muni an arm and leg.
The local "Catholic charity" runs a full time feeding station and no-cost flophouse for the 'homeless' The area is now lousy with drunks/crackheads. The ones living on the street are bad enough, but the ones 'camping' in the nearby woods are a eco-disaster 
Sad. I hate Russian literature because too much booze and not enough sun. Same problem in Alaska. I usually assume that “drunks” are self medicating because that’s what my son did for twenty years. He was bi-polar. Very bright. Tried so hard to be normal, took his meds but they didn’t keep up with this multiple health issues.
Good pic; that “environmental damage” has been used here in NJ when libs want homeless encampments in the woods removed by the government. They can pretend they still care about the homeless, but they care about the Earth as well (in fact, they just want them somewhere else).