“First, so many questions remain unanswered about the long-term effects of cannabis use. “Typically, long-term cannabis use impacts slow-wave sleep which, outside the context of cannabis, affects hippocampal function,” Brown said. “Sleep disruption from cannabis use isn’t necessarily insomnia-related or complete sleep deprivation; rather, it’s a reduction in the quality of sleep. “Acute cannabis use affects many things, including sleep and working memory, and the field is undecided on whether those memory issues resolve after continued abstinence,” she said. People who become dependent on cannabis for sleep risk developing a tolerance and requiring greater doses for the same effect.