Neurologic complications associated with novel influenza A (H1N1) virus infection include seizures, encephalitis, encephalopathy and Reye syndrome. Mania and psychotic episodes are less commonly described, and there have been limited studies on the long-term neuropsychiatric sequelae of H1N1 infection.
Here, we report a case of H1N1 infection with concurrent onset of acute manic and psychotic symptoms. Despite completing a full course of the antiviral medication oseltamivir, the patient’s behaviour worsened over the next four weeks and he required readmission for psychiatric treatment. Based on the temporal sequence of events, we considered the possibility that these symptoms were sequelae of Novel influenza A (H1N1) infection. Moreover, the manic symptoms persisted weeks after the acute infection had abated, which gives rise to the consideration of long-lasting direct or indirect neuronal insult by the influenza virus. However, it is also possible that his symptoms may have represented a primary psychiatric disorder precipitated by or coincident with the viral infection.