Cannabis increases susceptibility to false memory

Cannabis increases susceptibility to false memory

The main psychoactive constituent of cannabis has been associated with memory impairments. However, relatively little is known about the effects of cannabis on the generation of false memories.

The researchers conducted a double-blind, randomized, placebo-controlled study of false memory in 64 healthy, occasional cannabis users. In each experiment, the participants inhaled the vapor of a single dose of cannabis or a placebo and then performed memory tasks immediately afterward and 1 week later.

In the first experiment, cannabis-intoxicated individuals showed an increase in the false recognition of words that had not been previously presented. In two separate virtual reality experiments, the participants witnessed a fight or perpetrated a theft. The participants were then exposed to misinformation about the scenarios through suggestive questions during an interview or through the testimony of a second virtual witness.

The authors report that cannabis appeared to increase false memories for misinformation while subjects were intoxicated, but not 1 week later. According to the authors, the findings carry implications for the questioning of cannabis-intoxicated eyewitnesses and suspects during investigative interviews.