The average rate of people affected has been estimated to be around 30% for individuals taking antipsychotic medication, such as that used to treat schizophrenia. A study being conducted at the Yale University School of Medicine has estimated that "32% of people develop persistent tics after 5 years on major tranquilizers, 57% by 15 years, and 68% by 25 years." More drastic data was found during a longitudinal study conducted on individuals 45 years of age and older who were taking antipsychotic drugs. According to this research study, 26% of people developed tardive dyskinesia after just one year on the medication. Another 60% of this at-risk group developed the disorder after 3 years, and 23% developed severe cases of tardive dyskinesia within 3 years. According to these estimates, the majority of people will eventually develop the disorder if they remain on the drugs long enough.Elderly people are more prone to develop tardive dyskinesia, and elderly women are more at-risk than elderly men. The risk is much lower for younger men and women, and also more equal across the sexes. People who have undergone electroconvulsive therapy or have a history of diabetes or heavy alcohol use also have a higher risk of developing tardive dyskinesia.Several studies have recently been conducted comparing the number of people affected of tardive dyskinesia with second generation, or more modern, antipsychotic drugs to that of first generation drugs. The newer antipsychotics appear to have a substantially reduced potential for causing tardive dyskinesia.
Tardive dyskinesia (TD) is a disorder that results in involuntary, repetitive body movements, which may include grimacing, sticking out the tongue, or smacking the lips. Additionally, there may be rapid jerking movements or slow writhing movements. In about 20% of people with TD, the disorder interferes with daily functioning.Tardive dyskinesia occurs in some people as a result of long-term use of dopamine-receptor-blocking medications such as antipsychotics and metoclopramide. These medications are usually used for mental illness but may also be given for gastrointestinal or neurological problems. The condition typically develops only after months to years of use. The diagnosis is based on the symptoms after ruling out other potential causes.Efforts to prevent the condition include either using the lowest possible dose or discontinuing use of neuroleptics. Treatment includes stopping the neuroleptic medication if possible or switching to clozapine. Other medications such as valbenazine, tetrabenazine, or botulinum toxin may be used to lessen the symptoms. With treatment, some see a resolution of symptoms, while others do not.Rates in those on atypical antipsychotics are about 20%, while those on typical antipsychotics have rates of about 30%. The risk of acquiring the condition is greater in older people, for women, as well as patients with mood disorders and/or medical diagnoses receiving antipsychotic medications. The term "tardive dyskinesia" first came into use in 1964. Signs and symptoms
Tardive dyskinesia is characterized by repetitive, involuntary movements.