Mirtazapine-Associated Seizures in a 15-Year-Old Adolescent and a Case-Based Systematic Review

Purpose: To present a case of mirtazapine associated seizures in an adolescent boy and to conduct a systematic review of published cases of seizures occurring in association with mirtazapine use. Methods: We presented our case and conducted a systematic search, following the PRISMA Statement, in the PubMed and Scopus databases for mirtazapine associated seizure cases, until 12th September 2026. Results: A 15-year-old patient arrived at the emergency department of our hospital via ambulance due to a generalized tonic-clonic seizure occurring 15 minutes prior. The toxicology report of his urine sample was positive for mirtazapine metabolites. He was self-administering mirtazapine for an unknown amount of time. This was the most likely cause of the generalized tonic-clonic seizures. No further seizures occurred during hospitalization. Our systematic search yielded 7 published cases. The median age was 50 years. The dosage of mirtazapine ranged from 7.5 mg to 60 mg per day. Excluding one case with an overdose, seizures presented a few days after mirtazapine initiation or dosage escalation—three cases presented with focal seizures and 3 cases with generalized seizures. Two cases had a positive history of epilepsy, and 4 cases were on other medications that can lower the seizure threshold. In most cases, withdrawal of mirtazapine was sufficient for seizure resolution. Conclusion: The available evidence cannot establish a causative relationship between mirtazapine and seizures. The temporal association observed in several cases suggests that physicians should remain vigilant for seizure occurrence, particularly in individuals with pre-existing epilepsy or other potential seizure risk factors.