Did cavemen have psychological disorders?

Were psychological disorders around in prehistoric times?

Were there depressed cavemen, cavemen with anorexia or anti social personality disorder?

And if there wasn't, why not?

Have our brains developed the capacity for these things, could it be that increased intelligence causes problems such as increased serotonin levels.

If this is the case then why did our brains evolve to allow this, is there any benefit from these disorders or will there be further evolution in the future for these problems to disappear?