Most of the illicit drug emergency room visits involved multiple drugs.Heavy, long term exposure to marijuana may have biologically-based physical, mental, behavioral and social health consequences and may be "associated with diseases of the liver (particularly with co-existing hepatitis C), lungs, heart, and vasculature".Cannabis is mostly used recreationally or as a medicinal drug, although it may also be used for religious or spiritual purposes.
- in India and Nepal since the Vedic period dating back to approximately 1500 BCE, but perhaps as far back as 2000 BCE.
There are several references in Greek mythology to a powerful drug that eliminated anguish and sorrow.
Acute effects may include anxiety and panic, impaired attention, and memory (while intoxicated), an increased risk of psychotic symptoms, and possibly an increased risk of accidents if a person drives a motor vehicle while intoxicated.
Light and moderate use of cannabis is not believed to increase risk of lung or upper airway cancer.
Evidence for causing these cancers is mixed concerning heavy, long-term use.