All first-generation antipsychotics (FGAs) are known to do what to seizure threshold?

• A. True
• B. False
• C. Only high-potency FGAs lower threshold
• D. Only SGAs lower threshold

Answer: (A)

Seizure threshold is generally reduced by many antipsychotics, and this is a recognized effect of first-generation agents as a class. The reason is that dopamine D2 receptor blockade in brain circuits that control excitation and inhibition can shift the balance toward greater neuronal excitability. This tendency is seen more clearly at higher doses or in individuals with predispositions (such as a history of seizures, electrolyte disturbances, alcohol withdrawal, or recent dose changes).

High-potency FGAs (like haloperidol and others) tend to carry a higher risk, but many FGAs can contribute to lowering the threshold, especially with dose increases or rapid changes. Because of this, clinicians monitor for seizures when starting or escalating therapy and consider risk factors in choosing an antipsychotic or adjusting the regimen.

In contrast, while some SGAs (notably clozapine) are also known to lower seizure threshold, the question focuses on FGAs, and the overall class effect is to reduce seizure threshold, which is why this statement is considered correct.