Long-term cannabis use changes the structure of the brain and leaves users demotivated and unable to make decisions, a study suggests. Cannabis can be legally prescribed in Britain for some medical conditions and is often viewed as low-risk or harmless by recreational users. Leader author Ana Aquino-Servin said the findings mean that regular, heavy users of cannabis may find it hard to be motivated to do complex tasks. “Maybe they [regular cannabis users] don’t have a big struggle to do [tasks], but maybe the brain needs to do more work to do it. The analysis revealed the brain was thinner in the right rostral middle frontal cortex in people who had smoked cannabis daily for at least five years.

Source: Daily Mail March 30, 2026 19:52 UTC