Until recently, the best-known compound in cannabis was delta-9 tetrahydrocannabinol (THC). This is the most active ingredient in marijuana. Marijuana contains both THC and CBD, and these compounds have different effects.

• THC creates a mind-altering "high" when a person smokes it or uses it in cooking. This is because THC breaks down when we apply heat and introduce it into the body.
• CBD is different. Unlike THC, it is not psychoactive. This means that CBD does not change a person's state of mind when they use it.
• However, CBD does appear to produce significant changes in the body, and some research suggests that it has medical benefits.

All cannabinoids, including CBD, produce effects in the body by attaching to certain receptors. The human body produces certain cannabinoids on its own. It also has two receptors for cannabinoids, called the CB1 receptors and CB2 receptors.

• The CB1 receptors in the brain deal with coordination and movement, pain, emotions, and mood, thinking, appetite, and memories, and other functions.
• CB2 receptors are more common in the immune system. They affect inflammation and pain.
• CBD does not attach directly to either receptor. Instead, it directs the body to use more of its own cannabinoids.

Authors of a review from Neurotherapeutics found that CBD may help to reduce anxiety in people with certain related disorders.

According to the review, CBD may reduce anxiety-related behaviors in people with conditions such as:

• post-traumatic stress disorder
• general anxiety disorder
• panic disorder
• social anxiety disorder
• obsessive-compulsive disorder

People tend to use prescription or over-the-counter drugs to relieve stiffness and pain, including chronic pain. Some people believe that CBD offers a more natural alternative.

The researchers suggested that the non-psychoactive compounds in marijuana, such as CBD, could provide a new treatment for chronic pain.

A study in the Journal of Natural Products, published by the American Chemical Society, found that the extracts have a built-in capacity to attack and kill drug-resistant bacteria.

Some promising evidence suggests that CBD use may help people to quit smoking.

A pilot study published in Addictive Behaviors found that smokers who used inhalers containing CBD smoked fewer cigarettes than usual and had no further cravings for nicotine.

A similar review, published in Neurotherapeutics found that CBD may be a promising treatment for people with opioid addiction disorders.