A patient who started on a typical antipsychotic two weeks ago presents with severe restlessness and an inability to sit still. What is the most likely diagnosis?

Choice A reason: Pseudoparkinsonism typically manifests as motor slowing, also known as bradykinesia, along with muscle rigidity, a shuffling gait, and resting tremors. While it is an extrapyramidal side effect of antipsychotics, it presents with a lack of movement rather than the hyperactive restlessness described in the scenario. Choice B reason: Acute dystonia involves sudden, involuntary, and often painful muscle contractions, frequently affecting the neck (torticollis), eyes (oculogyric crisis), or tongue. It usually occurs within the first few days of starting medication and is characterized by rigid posturing rather than the subjective need to move. Choice C reason: Akathisia is a common extrapyramidal side effect characterized by a subjective feeling of inner restlessness and the objective inability to remain still. Patients often pace, rock back and forth, or tap their feet. It typically appears within days or weeks of initiating high-potency typical antipsychotics. Choice D reason: Tardive dyskinesia is a late-onset movement disorder resulting from long-term antipsychotic use, usually occurring after months or years of treatment. It is characterized by repetitive, involuntary movements such as lip-smacking, tongue protrusion, or choreiform movements of the limbs, rather than acute restlessness.