Involvement of non-opioid peptides in the pathogenesis of neurological and psychiatric disorders: evidence from CSF and post-mortem studies.

In the past twenty years, more than thirty peptides have been discovered to be present in the mammalian central nervous system (CNS). As the neuroanatomical distribution, neurochemical, electrophysiological and pharmacobehavioral effects of this novel group of neuroregulators have been described, it is evident that certain of these peptide-containing neural circuits may be pathologically altered in neuropsychiatric disorders. Although much attention has been focused on the opioid peptides, substantial data strongly support the hypothesis that non-opioid peptides such as somatostatin, neurotensin and substance P are altered in a diverse number of neuropsychiatric disorders including Alzheimer's disease, Huntington's chorea, Parkinson's disease, major depression and schizophrenia.