**Core Concept**
Neuroleptic malignant syndrome (NMS) is a rare, life-threatening disorder associated with the use of antipsychotic medications. It is characterized by fever, muscle rigidity, autonomic dysfunction, and altered mental status. The pathophysiology of NMS is thought to involve an imbalance between dopamine and serotonin in the brain, leading to an excessive release of dopamine.

**Why the Correct Answer is Right**
The exact mechanism of NMS is not fully understood, but it is believed to involve an idiosyncratic reaction to antipsychotic medications. These medications block dopamine receptors in the brain, but in susceptible individuals, this blockade may lead to an excessive release of dopamine, which in turn triggers a cascade of events resulting in NMS. The role of serotonin in modulating dopamine release may also play a crucial role in the development of NMS.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while anticholinergic medications can cause various side effects, they are not a primary cause of NMS.
**Option B:** This option is incorrect because while hypothyroidism can cause various systemic symptoms, it is not a direct cause of NMS.
**Option C:** This option is incorrect because while certain medications such as lithium and antidepressants can cause NMS-like symptoms, they are not the primary cause of NMS.

**Clinical Pearl / High-Yield Fact**
NMS is a medical emergency that requires immediate recognition and treatment. The diagnosis is primarily clinical, based on the presence of fever, muscle rigidity, autonomic dysfunction, and altered mental status in the setting of recent antipsychotic medication use.

**Correct Answer:** C. Antipsychotic medications.