History A 32-year-old-man presents with a several months history of strange experiences. He occasionally has a strange metallic taste sensation, which may last for a few seconds up to about a minute. He then has experiences that he finds difficult to describe. He imagines it is a bit like an out of body experience. There are times he has a feeling that everything around him is a repeat but at other times even familiar people and features completely baffle him.

After a few minutes, he is himself again but is often slightly disorientated and is frequently told that he has behaved rather oddly, for example, repeating automatic actions such as lip-smacking. He himself has no memory of this. There is a sense of something having been lost but he is not quite sure what. These episodes are increasing in frequency and his behavior stranger during them, which is the reason for seeking help now.…