Use of cannabis—marijuana and hashish—has increased dramatically in recent years in many developed countries, including the United States. Growing evidence suggests that the short-term effects of cannabis use are mostly positive, but little research has been done on the long-term effects of its use on cognition, especially in middle age or later life. In this study, researchers followed up with adults between the ages of 50 and 65 who had used cannabis heavily (at least five times per week) from 18 to 38 years old and compared them with nonusers to examine possible associations between cannabis use and cognitive performance.
Researchers have found that long-term cannabis use can lead to cognitive decline in midlife, including memory problems. One study found that those who had used cannabis for more than 20 years were more likely to have poor verbal memory and executive function than those who had not used cannabis. Cannabis use can also lead to changes in the brain’s structure and function, which may contribute to cognitive decline. Long-term cannabis users may also have difficulty learning new information and recalling old information. The good news is that the cognitive effects of long-term cannabis use are not permanent and can improve with abstinence from the drug.
There is evidence that suggests that long-term cannabis use may have an impact on visual spatial processing. One study found that regular cannabis users had lower scores on tests of mental rotation and surface unfolding than non-users. Another study found that long-term cannabis use was associated with impaired performance on a task requiring the visualization of complex objects. These findings suggest that long-term cannabis use may impact an individual’s ability to process information visually and spatially.
Despite conflicting evidence, other studies have found no such effects of long-term cannabis use on spatial skills. A systematic review of previous research concluded that there is insufficient evidence to support a correlation between long-term cannabis use and deficits in visual processing. These discrepancies may be explained by differences in study design, quality and sample size, as well as pre-existing differences between users and nonusers that could impact cognitive performance. For example, a recent study published by Jones et al.
According to a new study, long-term cannabis use may have cognitive effects in midlife. The study, which was published in the journal Addiction, looked at the reaction times of 489 middle-aged adults who had used cannabis for an average of 24 years. The researchers found that the longer someone had been using cannabis, the slower their reaction time was. They also found that people who used cannabis more frequently had slower reaction times than those who used it less often.
While some studies have shown that cannabis can slow reaction times, it is not clear if these cognitive effects persist after use is stopped. This study suggests that long-term cannabis use does have an effect on cognitive performance, but only up to four years after stopping use. After four years, reaction times returned to normal. There was no link between reaction time and how long ago someone last used cannabis or how much they had used in their lifetime.
The researchers also looked at other factors, such as socio-demographic and lifestyle factors like income level, alcohol use and employment status which are all associated with slower reaction times.
Executive Functioning and Reasoning
Cannabis use has been shown to have cognitive effects in midlife, specifically in the areas of executive functioning and reasoning. Executive functioning skills are important for everyday tasks such as planning, organization, and time management. Reasoning skills are important for solving problems, making decisions, and understanding complex information. Cannabis use has been shown to impair both executive functioning and reasoning skills in midlife. This is a concern because these skills are important for successful functioning in everyday life.
Adults who began smoking cannabis in their teens and continued to use it into midlife showed lower levels of a key brain protein compared with those who didn’t use cannabis, according to a new study. The findings suggest that long-term cannabis use may have negative effects on the brain.