Gamma-type endorphins: neurolepticum-like and antipsychotic action

The hypothesis implicating the gamma-type endorphins in schizophrenia was initially based on animal data showing commonalities between the behavioral effects of these peptides and neuroleptics. Clinical studies have shown that these peptides have an antipsychotic action in a number of patients suffering from schizophrenic psychosis. The patients responding to the peptides are characterized by features at least partly resembling those characterizing type I schizophrenia. This may be consistent with the animal data showing that gamma-type endorphins may directly or indirectly control certain dopaminergic systems present in the nucleus accumbens. Genetical differences may exist between patients susceptible to and not susceptible to gamma-type endorphins, as has been concluded from studies concerning antigens of the HLA system.