What are the long-term effects of marijuana on the brain?
Studies of man-made forms of the chemicals found in the marijuana plant can be helpful in treating nausea and vomiting from cancer chemotherapy. 1 Studies have found that marijuana can be helpful in treating neuropathic pain (pain caused by damaged nerves). 1
A few studies have found that marijuana can be helpful in treating neuropathic pain (pain caused by damaged nerves). 1 However, more research is needed to know if marijuana is any better or any worse than other options for managing chronic pain.
The impact depends on many factors and is different for each person. It also depends on the amount of tetrahydrocannabinol (THC) in marijuana (i.e., marijuana potency or strength), how often it is used, the age of first use, and whether other substances (e.g., tobacco and alcohol) are used at the same time.
At this time, there is not enough evidence to recommend that patients inhale or ingest marijuana as a treatment for cancer-related symptoms or side effects of cancer therapy.
Accidentally consuming or consuming too much cannabis at a time can lead to temporary adverse effects, also known as cannabis poisoning. Cannabis poisoning is not generally known to be fatal. It can, however, be very unpleasant and potentially dangerous, sometimes requiring emergency medical attention and, in some cases, hospitalization. Children and pets are at greater risk of cannabis poisoning.
Using cannabis frequently can lead to a pattern of problematic use or use disorder. This can result in dependence or addiction.
Everyone’s response to cannabis can also differ from one time to the next.
Cannabis for medical purposes
It is also easier to be poisoned when ingesting (eating or drinking) cannabis compared to inhaling cannabis (smoking or vaping). This is because some of these products may be confused with similar non-cannabis products. It can also take much longer to feel the effects. The result is that people consume more before they feel the full effects.
Youth and young adults are more likely to experience harms from cannabis because their brains develop until about age 25. The earlier you start consuming cannabis, the more harm it can do. Footnote 11
Some people use cannabis for their health problems. Deciding if cannabis is appropriate to treat your symptoms is best done in discussion with a health care provider.
Frequent use of cannabis over a long time can also harm important aspects of your thinking, like learning and memory. Stopping use can help improve these deficits. However, some of these harms may persist for months or years, or may not be fully reversible. Footnote 12 Footnote 13 Footnote 14