Opioid peptides and psychiatric illness

In the 10 years since Hughes et al (1975) identified from porcine brain two related pentapeptides with potent opiate activity, abnormalities of endorphin and enkephalin production or metabolism have been postulated in many disease states. The possibility of an advance in our understanding of the aetiology of functional psychiatric illness has led to a considerable body of research, which is discussed in this paper.