Secondary mania refers to a manic episode that arises during a medical illness other than bipolar disorder or in response to a drug or medication. As the psychopathological features of secondary mania resemble those of mania due to bipolar disorder, misdiagnosis is frequent.

We present the case of a 20-year-old woman who developed a manic episode with psychotic symptoms, in whom polymicrogyria, a malformation of the cortical development with abnormal electroencephalographic activity, was documented. After initiating antiepileptic management, the affective symptoms completely subsided.

To date, no specific recommendations are available concerning when to perform advanced studies in patients with a manic episode; however, as our case shows, these are much needed.

Because the treatment of secondary conditions largely depends on finding the underlying cause, patients with a new-onset mania should undergo a thorough assessment for secondary causes.