In their didactic poems on fishing and chocolate, both published in 1689, two Neapolitan Jesuits digressed to record and lament a devastating 'plague' of 'hypochondria'. The poetic plagues of Niccolò Giannettasio and Tommaso Strozzi have literary precedents in Lucretius, Vergil, and Fracastoro, but it will be argued that they also have a real, contemporary significance. Hypochondria was considered to be a serious (and epidemic) illness in the seventeenth century, with symptoms ranging from depression to delusions. Not only did our Jesuit poets claim to have suffered from it, but so did prominent members of the 'Accademia degl'Investiganti', a scientific society in Naples that was at odds with both the religious and medical establishments.