L-DOPA
The drug L-DOPA is used as a treatment for Parkinson's disease. Parkinson's disease is a case in which neuropathology results led to a successful treatment. Neuropathology studies showed light areas in the basal ganglia which should have been dark (due to neuromelanin). This was traced to a deficiency of dopamine, a precursor of neuromelanin. Since L-DOPA is a precursor of dopamine, it was used as a treatment. However, there were unfortunate psychiatric side effects. This was discussed in the book "Awakenings", written by the famous neurologist Oliver Sacks. It was also depicted in the movie based on the book. The fact that an increase in dopamine produces psychiatric side effects appears to suggest that a toxic metabolite of dopamine might cause schizophrenia. There are many theories of schizophrenia, some involving serotonin. Another theory is that a toxic metabolite of serotonin might cause schizophrenia. link to e-mail the author

Aldomet
This is a prescription drug used to control high blood pressure. Like other prescription drugs, it has side effects. Unfortunately, in common with a number of other drugs, it has psychiatric side effects. There is a pattern. Many drugs with a benzene ring and with a radical containing nitrogen, including amphetamine analogs, have psychiatric side effects. This also includes mescaline, L-DOPA, and others. Nexus is a drug of abuse. These facts support the catecholamine theory of schizophrenia. According to this theory, favored by Hoffer, Osmond, Freidhoff (deceased, unfortunately), Ridges, and others, a toxic catecholamine causes schizophrenia. Hoffer has also toyed with a toxic indoleamine theory. He once favored an epinephrine theory, but epinephrine theories have largely bitten the dust. Epinephrine is only found in minute quantities in the brain. Friedhoff favored a dopamine theory. link to more info

MONOAMINE OXIDASE INHIBITORS
Monoamine oxidase inhibitors block the metabolic breakdown of the catecholamines and increase the level of these amines in the brain, according to Nobel Prize winner Dr. Julius Axelrod. They are used to treat depression. These properties of the drugs cause many side effects, unfortunately. Other psychiatric drugs have different side effects because they do other things. Some antipsychotic drugs block dopamine receptors. Unfortunately those drugs can cause Parkinsonian side effects.

HYPERTENSION
Catecholamines are involved in regulating the blood pressure. When the blood pressure is too high, this is called hypertension. Hypertension, unfortunately, can be fatal. Hypertension can be a side effect of an interaction between MAO inhibitors and certain amines found in foods. Thus a person on MAO inhibitors must be very careful of what they eat. Cheese, for example, is forbidden, as is wine. Both are fermented. Tyramines are produced during fermentation. Fermented foods in general should be avoided. Diet is a definite factor in high blood pressure, even if the patient is not on MAO inhibitors. Part of this is due to cholesterol plaques which can accumulate in the arteries.