Doss MK, et al. - In view of the observation that the main psychoactive constituent of cannabis, Δ9-tetrahydrocannabinol (THC), impairs episodic memory encoding and modulates emotional processing, researchers for the first time investigated the effects of THC during retrieval of neutral and emotional episodic memories. They used a double blind, placebo-controlled, within-subjects design and analyzed healthy volunteers who viewed negative, neutral, and positive pictures (emotional memory task) and lists of semantically related words (false memory task). Adverse effects of THC during memory retrieval, distorting both neutral and emotional memories were revealed. These new retrieval findings in combination with THC’s known effects during encoding are relevant in light of the spreading acceptance of cannabis.