I would consult another psychiatrist; I see many ODD children put on mood stabilizers and it works to control their outbursts.
ODD techniques that work well include reward systems. Punishment, as you have found out does not work and can make things worse... but rewards with charts for good behavior seem to be effective. It's what we use when a child is hospitalized.
Find someone who specialized strickly in "behavior therapy". They can teach you exactly what to do and how to do it. Years and years or trial and error will not work, cognitive-behavior therapy will not work, punishment won't work.... Behavior Therapy will work. It only addresses behavior-- all else follows. You will learn how to properly reward, when to reward (that's called schedules of reinforcement) and bring him back under control.
Let me know if you have further questions.
Best of luck!!!