Can Weed Help Depression? CBD, Mood and the Psychosis Risk

Cannabis might help with depression, but the evidence is mixed: early research suggests CBD and the endocannabinoid system could play a role in easing low mood, chronic stress and anxiety, while heavy cannabis use, especially high-THC weed, is linked to a higher risk of psychosis and other mental health problems. The relationship between weed and psychiatric disorders is complex, and a lot more research is needed on its short- and long-term effects.

There's substantial, though not universal, evidence linking cannabis use to earlier onset of psychosis in people genetically predisposed to psychotic disorders such as schizophrenia, and to worse symptoms in people who already live with these conditions.

Less consistently, studies have also tied cannabis use to other mental health disorders and to self-harm, including suicidal thoughts and behavior. Understanding these links is essential for having an honest conversation about cannabis and mental health.

Weed, emotions and depression

Depression is more than just feeling sad: it's a mood disorder that takes a toll on emotions, thinking and behavior. It doesn't only hurt individual well-being; it's also a major cause of disability worldwide, showing up as a loss of joy and interest that drags down performance at work and school.

So how could cannabis contribute to treating mental health conditions? Much of the interest comes from how it compares with antidepressants. Cannabidiol (CBD), one of the compounds in cannabis, has shown psychiatric potential in research, with some similarities to antidepressants and anti-anxiety meds. Studies point to a strong interaction between CBD and the brain receptors involved in depression, anxiety and stress.

Researchers at the University at Buffalo's Research Institute on Addictions (RIA) have carried out studies suggesting that chronic stress and depression could potentially be treated through the endocannabinoid system.

This system works by activating CB1 receptors, found in the central nervous system (CNS) and peripheral nervous system (PNS). The brain makes its own chemicals, called endocannabinoids, that are similar to compounds in the cannabis plant, and that overlap is what makes the connection so interesting for treating mood disorders.

Drug-induced psychotic episodes

Research from Denmark has shed light on an intriguing phenomenon: cannabis-induced psychosis, a short-lived psychotic disorder linked to cannabis use. It's rare, with roughly 100 new cases a year across the country, and it tends to ease significantly once the person stops using cannabis.

The findings also turned up some worrying data among those cases:

• Three out of four were diagnosed with a new psychotic disorder within the following year.
• Almost half still had a psychotic disorder three years later.

These results raise the possibility that nearly half of the people diagnosed with cannabis-induced psychosis may be showing the first signs of a longer-lasting psychotic disorder, like schizophrenia.

This group could be especially vulnerable to cannabis's effects, which is why steering clear of it going forward matters for them. The data are preliminary, but they offer valuable insight into the relationship between cannabis and psychotic disorders and underline the need for more research.

What is cannabis-induced psychosis?

The link between cannabis use and mental disorders is a fascinating, constantly evolving field. It shows up more often in people who already have mental health symptoms, but more research is needed to fully understand it.

Several factors make the connection complicated, including how much and how often someone uses, THC potency, the type of cannabis product and the age of first use. Genetics, trauma and stress also influence both the likelihood of using cannabis and mental health itself.

What about other psychiatric disorders?

Research suggests cannabis use is associated with a higher likelihood of developing psychotic disorders, especially in people with a family history and other risk factors. Cannabis intoxication at high doses can trigger temporary psychotic episodes, which may be linked to a future risk of psychotic disorders.

For other mental disorders, the link with cannabis is less clear. Some research suggests a higher risk of depression in people who use cannabis as teens. More strongly, studies have found a link between cannabis use and suicidal thoughts and behavior, especially among teenagers and military veterans in the United States.

Despite these findings, the relationship between cannabis and mental health is complex enough that we need more data from prospective, long-term studies to pin down exactly how, and in whom, cannabis can contribute to worsening mental health. Those answers are key to understanding the risks and benefits of cannabis use when it comes to mental health.

Cannabis-induced psychosis is marked by episodes of severe hallucinations and delusions that are usually acute but do come to an end. It's uncommon, but it needs individualized treatment to keep those temporary episodes from coming back.

People with a genetic predisposition to paranoia or psychosis are much more likely to experience cannabis-induced psychosis. It's also important to stress that cannabis use can make other psychotic conditions a person already has worse.