Perron has published a number of papers on the psychological ramifications of bed bugs. In one study, he and his team looked at apartments that had been reported to the Montreal Public Health Department for unsafe conditions. Some of those units were infested with bedbugs, but not all of them. Perron and his team gave the tenants of these buildings a series of questionnaires that assessed all sorts of health impacts, including psychological ones. All told, 39 of the units had bed bugs, and 52 of them didn’t. When they compared the psychological results between those two samples—a method that helps to control for factors that impact mental health like socioeconomic status—they found that tenants with bed bugs were far more likely to report anxiety and sleep disturbances than those without.

Another study by medical entomologist Jerome Goddard at Mississippi State University examined posts on bed bug related websites like Bedbugger.com. When they compared those posts against a checklist of PTSD symptoms they found that 81 percent of people writing these forum posts were describing psychological and emotional effects often associated with the disorder, things like hyper-vigilance, paranoia, obsessive thoughts, and depression. “One person scored high enough to actually be considered a PTSD patient,” Goddard says. (The comparison they did here isn’t diagnostic. In other words, Goddard can’t actually diagnose anybody with PTSD from the results.)