It’s an open secret that Dahmer consumed a lot of alcohol, which led to the breakdown of relationships, the loss of employment, and eviction from at least one motel. Dahmer didn’t detail why he drank so much, but it’s believed he dealt with self-loathing due to his homosexuality by turning to the bottle. 

Furthermore, some theorize that Dahmer used alcohol to numb his emotions after a murder. However, alcohol use has never been touted as the reason Dahmer killed, leading to theories that Dahmer’s drug use contributed to his depravity. 

Jeffrey Dahmer used drugs to deal with a medical condition and to incapacitate his victims. 

Dahmer used drugs prescribed for insomnia to knock his victims out

Jeffrey Dahmer struggled with insomnia, so he sought medication to help him sleep. Doctors prescribed Halcion, a drug containing the sedative triazolam.

Dahmer used his prescriptions to incapacitate victims. He would crush pills containing triazolam and temazepam, another medication for insomnia, and pour the powder into the victim’s drink. 

After the victim passed out, Dahmer would kill them or perform brain surgery on them. Dahmer drilled holes in some of his victims’ skulls and injected diluted acid into their brains in twisted attempts to turn them into zombies.