I'm so sorry.
For two years, we were told that my son (difficult child 1) was manipulating us with oppositional behavior. He wouldn't do anything -- classwork, schoolwork, chores, showers, teeth brushing, you name it. When he completely shut down around Thanksgiving, we placed him in a day treatment program at a local psychiatric hospital for 6 weeks. The psychiatrist there adjusted his medications, and bingo, his oppositional behavior melted away. Even his outside psychiatrist is acknowledging that his new medications are causing him to be more cooperative and less depressed. In our view, he's a new kid.
Repeat after me: "difficult child is not manipulating me." He has a mental illness. He's on the wrong medications. The psychiatrist is not doing you any favors with his current medication mix. My strong suspicion is that both Prozac and Ritalin (and possibly even Clonidine) are causing the violent behavior rather than treating it. And Abilify, the only medication in the bunch that has any hope of calming him down, can't do its thing against the bad side effects of Prozac and Ritalin.
Is there any way you can get a second opinion from a new psychiatrist?