Medication and the VA hospital

My husband recently was diagnosed with ADHD at 59. He is now taking Ritalin. Through our health insurance, my husband worked with a psychiatrist who used the TOVA to decide which medication to use and to titrate the dose. We will soon be losing our health insurance and my husband will be relying on the VA, our only option due to pre-existing conditions. He has been seeing the VA psychiatrist every few months just to keep plugged in at the VA, but they do not write any prescriptions for him so far. But at the most recent visit to the VA, the psychiatrist refused to acknowledge that my husband has ADHD. Went on and on about his credentials and experience as a psychiatrist. Said he took an oath to "cause no harm" and that he would not write a prescription for Ritalin.

Is this a position held by the VA? Will the VA prescribe medication (Ritalin) for ADHD? Will requesting a change in doctor help?