Cannabis dampens the brain's response to music in regions involved in reward and emotion, including the auditory cortex, hippocampus, amygdala, and ventral striatum. However, when cannabis also contains cannabidiol, these dampening effects are offset, and brain activity does not differ from placebo. Despite reduced neural responses, both types of cannabis increased participants' self-reported desire to listen to music and enhanced sound perception. The findings suggest that cannabidiol may mitigate some of cannabis's effects on brain reward systems.
Inhaling nitrous oxide shortly after a traumatic event speeds the decline of intrusive memories, reducing them by the next day compared to four days later with medical air. The gas appears to disrupt memory consolidation, but it increases intrusive memories in people who were highly dissociated at the time of the trauma. Sleep quality did not differ between groups. The findings suggest nitrous oxide may help prevent PTSD symptoms in some individuals, but caution is warranted for those with dissociation.