Lee Hawker-Lecesne, lead therapist and addiction counsellor at The Cabin, looks at the rise in cannabis use and how cannabis-induced psychosis can impact mental health, well-being, and longer-term life opportunities.

Covid drastically changed people’s social habits. Surveys show that young people began smoking more and drinking less during Covid. As no sanctioned places are available for public consumption of marijuana, cannabis use remains something that people often do in their homes. 

Studies have also shown cannabis use has risen in correlation with reported mental health issues, people are using it as a form of self-medication from the residual effects of the trauma Covid caused. 

A more mainstream permissive view of cannabis has also evolved over the last 3–5 years following decriminalisation in the continental US and some Asian countries.

This global sea change, in my opinion, has sanded away many traditional apprehensions. Despite people having started drinking more during isolation at the beginning of the pandemic, many are now trying to balance that with cannabis use for health reasons and self-medication for stress, anxiety, and depression.

Unfortunately, the advertising of medical marijuana does not tell the full story.

• Research into drug trends shows that 7 out of 10 drug purchases across all periods of the pandemic were for cannabis.
• We know from multiple surveys that drug use has increased rather than decreased since the pandemic.
• Of particular concern is that marijuana use increases the risk of developing several psychiatric conditions, including schizophrenia, depression, and anxiety.

Gateway drug

Because of sub-cultural norms, permissive values of group members and the increase in potential exposure to other drugs, cannabis has become a gateway drug. Where there is cannabis use, there is an increased chance of other drug availability; for those willing to experiment, this can lead to developing other substance use disorders.

Cannabis-induced psychosis

Cannabis is a known risk factor for the onset of schizophrenia and cannabis-induced psychosis. While the underlying mechanisms are not well understood, studies have found that cannabis use is involved in 50% of schizophrenia, psychosis, and schizophreniform psychosis cases.

A study found that people who smoke marijuana daily have a five times greater risk of developing psychosis than those who have never smoked marijuana.

Factors that make a person experience psychosis after using marijuana

• Heavy marijuana use.
• Chronic, long-term use.
• Age
• Existing vulnerability to psychosis.

When people experience psychosis due to marijuana use, they may experience several different symptoms associated with a break from reality. Symptoms of marijuana-induced psychosis include.

Hallucinations

These are characterised by sensory experiences that are not real, including seeing, hearing, or feeling things that do not exist.

Paranoia

This type of thinking causes people to feel suspicious and distrustful of others.

Grandiosity

This involves having an exaggerated sense of power and importance. People experiencing grandiosity often feel they are superior or invulnerable to harm.

Feelings of being persecuted

This is an aspect of paranoia where people believe others are trying to harm them.

Of particular concern is teenagers who use marijuana; adolescents have a higher risk of experiencing psychosis. Research suggests this might be due to the emotional challenges that sometimes contribute to marijuana use. Regular marijuana use by teens also affects the brain in various ways, impacting cognition, learning, and development.

Research shows that people who use marijuana and have a certain variation of the AKT1 gene, responsible for coding for an enzyme affecting dopamine signalling, are at a greater risk of experiencing psychosis.

People who have this genetic variant and who use marijuana daily have a seven times higher risk of developing psychosis. Other gene variants also increase the risk of adults who use marijuana as teens develop psychosis.

People may also experience other symptoms during a psychotic episode, including irritability, anxiety, or racing thoughts. When psychosis is triggered by using a substance such as marijuana, these symptoms are acute rather than persistent. This means they typically resolve once the substance leaves the body.

However, the consequences of what happens while someone may be experiencing cannabis-induced psychosis may be far longer. Impaired judgment and reasoning can easily lead to further drug use with increases over time rather than a decline.

Cannabis-induced psychosis can also impact mental health and well-being, increasing the likelihood of progression to habituated use of cannabis and other drugs through social group membership and affecting longer-term life opportunities.