Tardive Dyskinesia Statistics

Tardive dyskinesia (TD) is classified as a “rare” disease by the National Organization for Rare Disorders, meaning that less than 200,000 people in the United States are affected by the condition, as stated in the Rare Diseases Act of 2002. While 200,000 may seem like a small number, for each of those individuals who have TD, the weight on their shoulders is tremendous. It is difficult to pinpoint the exact number of people who currently suffer from TD, as no large-scale survey has been taken and the condition can be transient. The condition currently has no standard treatment.

How common is TD?

According to statistics compiled by Mental Health America, an estimated 10 to 20 percent of individuals treated with an antipsychotic medication will develop tardive dyskinesia, typically if the medication has been used for three months or longer. Neuroleptic drugs, including certain antipsychotics and gastrointestinal medications such as Reglan (metoclopramide), have been shown to cause the disease and its debilitating symptoms.

Research studies have shown that patients who take metoclopramide for more than 90 days – the recommended minimum treatment time for the medication – have a relatively high chance of developing tardive dyskinesia. Unfortunately, many individuals are prescribed metoclopramide drugs for much longer than three months, and the risk of TD increases with the duration of treatment and the total cumulative dose.

How are antipsychotics linked to TD?

Patients taking typical antipsychotic or neuroleptic agents such as chlorpromazine or haloperidol have also been shown to have a tendency to develop TD after long-term use (longer than three months) of the drug. An estimated 20 to 30 percent of chronic schizophrenics receiving treatment with these medications develop the disease, which can be permanent.

Is TD always severe?

An estimated 60 to 70 percent of TD cases are considered "mild," with only 3 percent of cases deemed "extremely severe." As outlined by Mental Health America, severe cases involve problems such as speech interference, respiratory difficulties, problems with swallowing, and cosmetic disfiguration.

Who is at a higher risk of developing TD?

Certain populations taking metoclopramide, prescribed to treat problems such as gastric reflux disease and heartburn, may be at a higher risk of developing TD. Populations at a increased risk of developing TD include the elderly, post-menopausal females, patients with a history of alcohol abuse, substance abuse, or mental retardation, and those taking older generation antipsychotics.

Currently, though, there is no definitive information as to why some individuals develop the disorder and others do not.

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