Emerging influenza and psychosis: an important story in psychological medicine.

Sir,

The present public health concern is on the emerging influenza, which has already been spread in several states of USA. Indeed, there are many epidemics of influenza in the past decade including swine flu and avian flu. Although influenza is an infectious disease with predominant respiratory manifestation, the psychological problem can be seen. It has been mentioned for a long time for the relationship between psychosis and influenza. Historically, the concern was proposed in the big Hongkong flu 1971/1972.[1] Thraenhart et al., reported that influenza virus (A/Hong Kong/1/68 (H3N2) could be isolated from spinal fluid of the patients presenting with the psychological problem, paranoid psychosis.[1] The continuum psychological medicine on the neuropsychological effect of influenza can be seen. It is accepted that “maternal influenza viral infection increases the risk for schizophrenia in the adult offspring.”[2] In a recent animal model study by Moreno et al., it was observed that “cortical 5-HT (2A) receptor-dependent signaling pathways are significantly altered in the offspring of infected mothers.”[2] In non-obstetrical condition, there are also some reported relationships between influenza and psychosis. Okusaga et al., found that seropositivity for influenza B was significantly related to psychosis.[3] Based on the mentioned evidence, psychosis should be the focus in psychological medicine in the present era of emerging influenza.