Chronic use of anti-psychotic drug can lead to: September 2006
**Core Concept**
Chronic use of antipsychotic drugs can lead to a range of side effects due to their impact on the dopaminergic system in the brain. Antipsychotics primarily act by blocking dopamine D2 receptors, which can lead to changes in the brain's reward and motor control systems.
**Why the Correct Answer is Right**
The most significant concern with long-term antipsychotic use is the risk of developing **tardive dyskinesia**, a condition characterized by involuntary, repetitive body movements. This occurs due to the blockade of dopamine D2 receptors in the basal ganglia, which leads to an imbalance in the neurotransmitter systems controlling movement. The exact mechanism is not fully understood, but it's thought that the prolonged blockade of D2 receptors may lead to changes in the expression of genes involved in movement control.
**Why Each Wrong Option is Incorrect**
**Option A:** While antipsychotics can cause weight gain and metabolic changes, this is not the primary concern with long-term use.
**Option B:** Extrapyramidal symptoms (such as dystonia and parkinsonism) are a common side effect of antipsychotics, but they are typically reversible with dose reduction or medication.
**Option C:** Sedation is a common side effect of antipsychotics, but it is not a long-term consequence of chronic use.
**Clinical Pearl / High-Yield Fact**
To remember the risk of tardive dyskinesia, recall that antipsychotics can "block the brakes" on dopamine, leading to an imbalance in movement control.
**Correct Answer:** C.