Ignasi Agell explains this branch of psychiatry in the United Kingdom
At medical school, your experience of psychiatry is mainly limited to an attachment to a psychiatric service, which is likely to be in general adult psychiatry. Spending occasional time in clinics and on ward rounds trying to elicit symptoms may have given you the impression that you will never use these skills after your exams, unless you want to be a psychiatrist. Nothing could be further from the truth because psychiatric problems are present in all branches of medicine.
Liaison psychiatry is a subspecialty within psychiatry, which is concerned with the overlap between psychiatry and the rest of medicine and surgery. Its scope ranges from psychological reactions to physical illness, deliberate self harm, and somatoform disorders, among others.
Liaison psychiatry services are not sufficiently developed to be divided into subspecialties but many liaison psychiatrists develop specific areas of interest, each with its own particular differences. Some are listed in the