What is tardive dyskinesia and its primary risk factor?

• A. Severe dehydration; risk increases with hot weather
• B. Chronic seizures; risk increases with sleep deprivation
• C. Involuntary repetitive movements often after long-term antipsychotic use; risk increases with older age and prolonged exposure
• D. Sudden weight loss; risk increases with high exercise

Answer: (C)

Tardive dyskinesia is a movement disorder caused by long-term blockade of dopamine D2 receptors from antipsychotic medications. It presents with involuntary, repetitive movements, often of the face, mouth, tongue, or limbs, that can appear after months or years of treatment. The main risk factor is older age combined with prolonged exposure to antipsychotics; risk increases with longer duration of use and higher cumulative dose. This is why the choice describing involuntary movements after long-term antipsychotic use and noting that risk rises with older age and prolonged exposure fits best. The other options describe issues (dehydration, seizures, weight loss) that are not characteristic of tardive dyskinesia or its pharmacologic risk pattern.