This is major, in a study in Finland, (link below) giving 200 mg of an antihistamine called famotidine to patients with treatment resistant schizophrenia reported decreased symptoms in a week and in a month had statistically significant decreases in their symptoms!
The drug penetrated the blood brain barrier and effectively blocked histamine from binding the H2 receptors, and this drug affected signaling molecules shown to be involved in schizophrenia.
If this works for all people with schizophrenia, it will be a godsend! Then the awful antipsychotic medications, with their awful, awful, side effects, may not have to be used, or may be used in reduced doses.
This may also work for people with bipolar d/o, when they are in a psychotic (out of touch with reality) phase.
This is so amazing! That something so mundane as an antihistamine can actually treat a complicated and awful disease such as schizophrenia! This shows the power of biological/medical research, how discoveries can change treatment of horrible diseases for the better and improve the quality of life of people who suffer from such diseases.