Harriet Washington’s latest book is a fascinating jaunt through current and historical research into the infectious origins of mental illness. From the link between schizophrenia and Toxoplasma gondii (a parasite that can only reproduce within the digestive tract of felines and is known to make rats go wild at the scent of cat pee) to the sudden manifestation of anxiety following strep throat in some children (a syndrome known as PANDAS), Infectious Madness comprises a greatest hits of microbial mischief.

Along the way, Washington sorts through piles of evidence which suggest that many conditions ascribed to genetics, trauma, or stress—or, in particularly retro circles, character flaws or demonic possession—could sometimes be triggered by bacteria, viruses, or parasites. Interest piqued, I found myself taking breaks to dig through PubMed for even more information. Perhaps Washington’s lively and accessible explanations made even complicated medicine and epidemiology seem within my reach.

In all, Infectious Madness is a highly engaging read which will leave you longing for a sequel.