I have been medicated, mostly with Zyprexa, for about 12 yrs.  It does work well for me.  But I have taken myself off of it many times.  The thing is, once I start feeling better, I either deduce I must be well, or that I simply no longer need the medication and "test" myself by noncompliance to see if it is true.  Sometimes I decide I was probably never sick in the first place -- it was a mistaken diagnosis.  No one understands this, not even me. 

At first, I hated psychiatric hospitals.  They seemed like only more torture added to my days.  I even had electroconvulsive therapy many times to try to break the hold the illness had on me.  I attempted suicide a few times.  Gradually, I became grateful for a safe place to be.  I knew they would take good care of me and keep me from hurting myself or others.

Finally, in 2002 my psychiatrist came into my hospital room and said, "I'm going to lay it on the line.  If you don't start taking your medications as prescribed, you are going to continue to go straight downhill.  You will never get any better.  And in a few years you will be totally dependent on others for your simplest needs and care."  Well, that scared me.  That was not what I wanted.  So for a long time, I did take the meds as prescribed.  I hated the weight gain and sedation (and still do.)  Now, occasionally I go off the Zyprexa on my own again.  I soon feel the symptoms coming back and start taking it again.  A rollercoaster that is surely hell for my brain, as if it has not been insulted enough already by the illness itself.

I think you are doing right by keeping your friend hospitalized until he is stabilized on medication and understands that he must take it to be allowed back into society.  And he hopefully will like the part about feeling so much better and decide it is the right thing to do.

Best wishes to you.