We agree with Dr Hambridge that trainees can have of a tendency to order more unnecessary investigations than consultants, although for an expensive investigation such as an EEG, one would hope that the consultant in charge would approve the request. Unfortunately, we did not collect data on this. We also agree that sometimes investigations must be carried out even if the expected yield is low. An EEG looking for evidence of diffuse slowing that might indicate an organic brain disorder is a particularly useful indication.

We were not advocating that psychiatrists must never request an EEG, but that they should be aware of its considerable limitations, particularly in the diagnosis of epilepsy. The fact that 29 of the 187 EEGs demonstrated temporal lobe dysfunction is of little help in the diagnosis of temporal lobe epilepsy, first, because the diagnosis of temporal lobe epilepsy depends primarily on a good history and witness account and second, because of the frequency of temporal lobe dysfunction, both in the population and in a number of psychiatric disorders.