Environmental Toxins - Tardive Dyskinesia Risk Factors

The use of medication in the treatment of mental disease has been standard practice in the U.S. since 1954, when the pharmaceutical company Smith Kline & French (predecessor to GlaxoSmithKline) began marketing its drug Thorazine. Within three years, patients on this and similar medications began to display a loss of control over voluntary muscle function, primarily of the face and around the lips, jaw and tongue.

By 1964, these symptoms had a name: tardive dyskinesia.

It has now been well established that the symptoms of tardive dyskinesia result not only from the use of "first generation," or "typical" anti-psychotic medications, but also from the more recent "second generation," or "atypical" ones as well. The only difference is in the length of time it takes for the patient to develop symptoms; studies have shown that the newer medications may delay the onset of tardive dyskinesia symptoms.

Risk Factors

However, tardive dyskinesia is a complicated condition with numerous risk factors. Although anti-psychotic, or neuroleptic medications are the major trigger for tardive dyskinesia in the 30 percentof mental patients on neuroleptic prescriptions (some of these medications are also used to treat gastrointestinal disorders), there are many other factors that can make a patient more susceptible:

Gender (females are more likely to develop symptoms)
Age (most tardive dyskinesia victims are 55 years of age or older)
Length of time on the medication (tardive dyskinesia symptoms can appear after six months)
Dosage (higher dosages raise the risk of symptoms
Family history (genetic factors - this also includes ethnicity, as people of African
Ancestry are especially susceptible
Use of alcohol and/or OTC medications

One factor that is not commonly discussed however is the presence of environmental toxins.

In The Air, Ground and Water

Over the past generation (and since 2001 especially), freedom to do business, for major corporations, has been the freedom to foul the environment with an appalling number of toxic chemicals and waste products with no obligation to clean up the mess (the assumption - and sadly, the practice - has been to leave this responsibility to the taxpayer).

It is no secret that environmental toxins - particularly mercury - have had a serious effect on the mental processes of those individuals who are exposed. However, the effect of exposure to specific environmental pollutants on the development of tardive dyskinesia in particular has not been studied widely. The effect of environment on predisposition to tardive dyskinesia has been considered, however. In addition, there are toxins that, while existing in the environment, are not necessarily the direct product of corporate industry, but rather those that persons choose to inflict upon themselves - namely, nicotine, alcohol and caffeine.

Tardive Dyskinesia and Nicotine

Neuroleptic medications operate on what are known as dopamine receptors. These are areas on the body's cells that "interface" with the nervous system, receiving instructions from the brain. Dopamine is the chemical that facilitates communication between the nerve endings (synapses) and the cellular receptors. Anti-psychotics act to block these receptors.

There are several different types of dopamine receptors, which medical researchers identify by number. Neuroleptic medications target the receptor known as D2, which is involved in emotional response and basic cognitive functions. This receptor has long been associated with tardive dyskinesia, although researchers are now finding that other receptors are implicated as well.

Dr. John Brasic of the Johns Hopkins University School of Medicine led a research project of which the results suggest that "cigarette smokers appear to have increased metabolism of dopamine D2 antagonists." In other words, something about nicotine causes these patients to absorb and process greater amounts of the active substance in anti-psychotic medications in greater quantities at a faster rate, causing the development of symptoms.

Tardive Dyskinesia and Alcohol

It is not unusual for schizophrenics and other mentally ill individuals to abuse alcohol and narcotics. However, the greatest danger appears to stem not necessarily from consumption of alcoholic beverages, but rather the alcohol that is contained in many OTC medications, particularly those formulated for young people. These medications can actually exacerbate the side effects caused by antipsychotic medications.

Tardive Dyskinesia and Caffeine

Considering that caffeine is a stimulant, it would seem reasonable that consumption of beverages containing this substance would aggravate the symptoms of tardive dyskinesia. However, the results of studies in this area have been mixed; it is still not clear what role caffeine plays in the development of tardive dyskinesia, if any. Studies do suggest however that those with schizophrenia also ingest large amounts of caffeine; since this particular toxin enhances the effects of dopamine, it would seem that tardive dyskinesia symptoms would correspondingly be exacerbated. On the other hand, the human body can and does develop a toleration for caffeine, which would negate such effects. It would appear that additional studies are necessary in order to determine exactly how caffeine interacts with antipsychotics.