My son is 15 and has been taking Depakote for 6 years. He stoppe...

My son is 15 and has been taking Depakote for 6 years. He stopped taking it about 3 weeks ago. He says he feels fine. Is it okay to stop taking it cold turkey. He has a doctor appt next month and I would prefer him to be off of it. He was diagnosed with mild bipolar for his mood swings. I just want to make sure there are no real concerns with him stopping the medication so abruptly. (The only side effect he had during his taking the medication was that his legs hurt him) Thank you.