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: Involuntary lip-smacking and facial grimacing are classic signs of tardive dyskinesia, not pseudoparkinsonism. These symptoms result from dopamine receptor supersensitivity in the nigrostriatal pathway after prolonged blockade and are often irreversible, unlike the symptoms associated with drug-induced parkinsonism.

Choice B reason: Acute muscle spasms, particularly those that result in abnormal posturing of the head or trunk, indicate acute dystonia. This is a rapid-onset extrapyramidal reaction that requires immediate intervention with anticholinergic medications like benztropine, whereas pseudoparkinsonism involves more generalized rigidity and slow movement patterns.

Choice C reason: The subjective and objective need to move, or the inability to remain seated, defines akathisia. While both are extrapyramidal symptoms caused by dopamine blockade, akathisia is a disorder of movement urgency, whereas pseudoparkinsonism mimics the motor deficits of idiopathic Parkinson’s disease.

Choice D reason: Pseudoparkinsonism is characterized by a constellation of symptoms including "lead-pipe" muscle stiffness, a shuffling gait with a narrowed base, and a mask-like facial expression. These symptoms are caused by the blockade of dopamine D2 receptors in the basal ganglia by antipsychotic medications.

Choice A reason: Social anxiety disorder focuses specifically on the fear of being scrutinized, judged, or embarrassed by others in social or performance-related situations. While it may lead to staying at home, the core fear is social evaluation rather than the logistical inability to escape a specific physical environment or situation.

Choice B reason: Agoraphobia is characterized by marked fear or anxiety about being in situations where escape might be difficult or help might not be available in the event of developing panic-like symptoms. This often leads to "homebound" behavior, where the individual feels safe only within their own residence and avoids public spaces or transportation.

Choice C reason: Generalized anxiety disorder (GAD) involves excessive, uncontrollable worry about various aspects of daily life, such as health, finances, or work. While GAD is pervasive and distressing, it is not characterized by the specific situational avoidance or the localized fear of being unable to escape that defines agoraphobia.

Choice D reason: Panic disorder is defined by recurrent, unexpected panic attacks and the persistent worry about having more attacks. While agoraphobia often develops as a complication of panic disorder (as the patient fears having an attack in public), the specific fear of being unable to escape situations is the defining feature of agoraphobia itself.