I have been notified that a patient of mine has been diagnosed ADHD by a psychiatrist.

His employer noticed that he was very anxious and jumpy, and the possibility of ADHD was raised. The employer sent the patient to an occupational physician who in turn referred him on to a psychiatrist. The patient was unknown to either of these doctors. He denied any history of drug abuse and, following a diagnosis of ADHD, a prescription of methylphenidate was issued.

I know the patient very well, having counselled him during several years of opiate addiction. He has a long history of polypharmaceutical abuse. The employer, the occupational physician and the psychiatrist were observing behaviour caused by opiate withdrawal and possibly methamphetamine abuse.

I was not involved in the referral process. The disastrous decision in 1999 by the Ministry of Health to take general practitioners out of the loop has meant that the doctor who knows this patient best is no longer involved in the diagnosis and treatment of his ADHD.

This has created an intolerable situation for the psychiatrist involved who has been forced to make a complex diagnosis about a complete stranger.

This is far from the first instance of inappropriate prescription of methylphenidate that I have observed.

Methylphenidate prescriptions are running at an all-time high. A total of 72 186 prescriptions were written in 2002, a 25-fold increase from 2906 in 1993. Its availability makes it by far the cheapest drug on the black market, fetching only $5.00 a tablet.

Clearly it is time for review.