Anxiety is a common problem for many people. 

Anxiety disorders affect an estimated 20% of U.S. adults each year. Studies suggest that CBD may help with symptoms of anxiety. One study look at the possible neural basis for CBD reducing symptoms of social anxiety disorder. A study from 2015 found that participants using CBD saw improvements in many mental conditions including generalized anxiety disorder, obsessive compulsive disorder, panic disorder, social anxiety disorder and post traumatic stress disorder. 

However, the authors of the study note that while the substance has considerable potential, further research is needed to better determine the therapeutic benefits and long-term effects.

Some antidepressants work by acting on serotonin receptors in the brain. Low serotonin levels are linked to depression, and animal studies suggest that CBD might have an impact on these receptors which may produce antidepressant effects. 

One study found that the antidepressant-like effects that CBD produces depend upon the serotonin levels in the brain. Cannabidiol is argued to not increase serotonin levels. However, it is believed that it affects how your brain reacts to serotonin that is already in your body. 

Because CBD may have a calming effect, it may also hold promise in treating insomnia. The Centers for Disease Control and Prevention (CDC) reports that a third of U.S. adults do not get the recommended amount of sleep each night. This is problematic since not getting enough sleep is linked to health conditions such as depression, type 2 diabetes, obesity, and heart disease. 

One study conducted with adults found that 65% experienced improvements in sleep quality scores after a month of taking an average of 25mg of CBD daily, although those scores fluctuated over time. An overall consensus was that more research is needed. 

PTSD affects approximately 7% of U.S. adults. It is characterized by symptoms including re-experiencing traumatic events, intrusive thoughts, nightmares, and avoidance of things that may trigger memories of the trauma. Some research suggests that CBD may be helpful in reducing the symptoms of this condition. 

One study found that an oral dose of CBD in addition to routine psychiatric treatment for PTSD was associated with a reduction in symptoms.

Put simply, the evidence we currently have shows that more evidence is needed. This may change in the future as more research is carried out.

Many experts remain optimistic that CBD may prove useful for a range of mental health conditions. Another study did find that pharmaceutical TCH, both with or without CBD, was linked to small improvements in symptoms of anxiety among people with other medical conditions such as chronic pain and MS, although this evidence was considered low-quality.

This does not mean that CBD isn't necessarily effective. Of the studies reviewed, most only included a small number of participants, followed participants for a short period of time, and less than half were randomized controlled trials.