Toby used to carry around his clozapine (mood stabilizers to keep his bipolar at bay), but he kept losing them. Finally, Slender, sick of his bipolar-induced mood swings, entrusted his pills to Masky, much to proxy's chagrin. Now whenever Toby's bipolar kicks in, Masky gets in trouble for not giving the pyromaniac his pills, even though 99% of the time Toby avoids Masky on purpose to get him in trouble.

(And unless I am greatly mistaken (apologies if I am) clozapine is also used for schizophrenia.)