Like any drug, marijuana is known to have side effects that can exacerbate or diminish certain mental health conditions.
The Status Of Marijuana
Marijuana is a popular drug that is consumed in the United States and the rest of the world. The National Institute on Drug Abuse (NIDA) reports that 22.2 million people reported using the drug in the past month in 2015.
The National Conference of State Legislatures reports that as of 2019, 11 states have made recreational marijuana legal for adults. Twenty-six states have decriminalized set amounts of marijuana, which means that residents of these states will not immediately go to prison for carrying cannabis.
Why Is It Hard To Understand Marijuana’s Effects On Mental Health?
In January 2019, Scientific American explained that although cannabis comes from one plant, it contains up to 500 different chemical components, and not all of them cause the same effects. Cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) are found in marijuana .
- CBD is known for causing relaxation and fending off psychosis.
- THC is associated with feelings of anxiety and psychosis, including paranoia. THC can also amplify a user’s negative state of mind, but it can help them feel better if they are in a positive state.
Data on the relationship between marijuana and mental illness seems conflicting because some studies focus on the effects of CBD, while others focus on THC. Taking this into account, it seems marijuana can both help and harm people with mental health disorders, depending on the chemical component and the mental health disorder in question.
Effects Of Short-Term Marijuana Use
According to a July 2014 article from Psychology Today, scientists discovered that the brain has cannabinoid receptors in 1989. Receptors in the brain explain why marijuana causes a high when used. Documented short-term effects of marijuana include:
- Increased appetite. Known as the munchies, marijuana is thought to affect the part of the brain that releases hunger hormones leptin and neuropeptide Y. These are responsible for regulating your appetite.
- Diminished pain. Nerve cells in the body have cannabinoid receptors. This explains why marijuana is known to decrease pain levels.
- Loss of coordination. Marijuana can affect your motor control. It is known to impair driving ability, just as alcohol does.
- Memory impairments. Getting high on marijuana can make it harder to remember new information. Your old memories stay intact, but you temporarily lose the ability to make new ones.
- Lessened anxiety. Psychology Today states that THC pairs itself with the part of the brain that assesses threats, and it may decrease anxiety in some patients. More data is needed to prove whether or not marijuana can reduce anxiety on its own, or if people self-medicate with marijuana and feel decreased anxiety as a result.
Effects Of Long-Term Marijuana Use
Per the National Institute on Drug Abuse (NIDA), studies about the long-term effects of using marijuana are not yet conclusive. However, some studies show marijuana has these long-term effects:
- Decrease in IQ: Studies about marijuana’s effect on IQ are still not conclusive. NIDA mentions that loss of IQ could be possible if long-term users of marijuana begin using at a younger age.NIDA also discusses a study on twins that shows marijuana use may not necessarily result in a loss of intelligence, but more studies need to be conducted to have a definite answer. It is best that adolescents and young adults abstain from marijuana or avoid using it frequently.
- Behavioral problems: As mentioned by the CDC, babies, children, and adolescents tend to suffer from marijuana’s worst effects because they are still developing. Babies whose mother used marijuana consistently throughout pregnancy are known to have behavioral problems. Attention, memory, and critical thinking skills, which are necessary for problem-solving, suffer throughout their childhood.
Factors That Influence How Marijuana May Affect Mental Health
A June 2014 case report published by The New England Journal of Medicine says a few factors may influence whether marijuana can influence mental health. These factors include:
- Marijuana’s strength. Stronger marijuana strains and daily consumption of marijuana are linked to psychosis, according to a July 2019 report from BBC News. Potent marijuana is known to have more THC, the active ingredient that makes people feel high.
- Presence of schizophrenia. Per a January 2018 article from Psychology Today, it is unclear whether people who already have schizophrenia use marijuana to cope with this mental illness or if the drug triggers the disorder in those already prone to it.
- Age of first use. Using marijuana regularly or in large quantities at a young age is known to harm the development of white matter in the brain, per The Conversation. White matter allows the brain to send messages. Disruptions in the brain during the teen years can cause problems for years to come.
- Genetic predisposition. The National Institute on Drug Abuse (NIDA) says that using marijuana at a young age can trigger psychosis and other mental health issues in people who possess a gene called AKT1, which is linked to psychosis.
- Marijuana’s long half-life. Psychiatry explains that it can take anywhere from a week to 30 days for a person’s body to get rid of cannabis. Its long presence in the body can provoke the manifestation of a pre-existing mental health condition.
Per Psychiatry, marijuana is known to cause paranoia, feelings of persecution, panic, and feelings of psychosis in approximately 15 percent of people who use it. Scientists believe there are two reasons why this happens, but more data is needed. - Propensity for mental health issues. Some people are susceptible to certain mental health conditions. Marijuana use may cause these conditions to develop faster.
Mental Health Issues Linked To Marijuana Use
Mental health issues span several conditions, but some have been strongly linked to marijuana use.
- Depression: As stated by Mayo Clinic, people who smoke marijuana are more likely to be diagnosed with depression than people who do not consume the drug. It is not clear whether people who are already depressed use marijuana to cope with their symptoms or if marijuana triggers this.
- Detachment from reality (psychosis): A January 2016 case study published by Neuropsychopharmacology says that people who are genetically predisposed to experiencing psychosis are likely to experience it up to seven years earlier if they smoke marijuana. The risk of psychosis also goes up fivefold, or even sevenfold, in people who use marijuana every day.
- Bipolar disorder: A case report covered a 21-year-old African American male who used marijuana and then developed bipolar disorder. The patient had been hearing voices and was even admitted to a hospital for 30 days following a psychotic episode after using marijuana. The report highlighted that up to 41 percent of people diagnosed with bipolar disorder use marijuana.
- Schizophrenia: A 2017 report from the National Academies Press states that people who have schizophrenia use marijuana at rates higher than the general population. In addition, people with schizophrenia who use marijuana are more likely to experience its symptoms in more obvious ways than people who do not have the disorder. They may experience more pronounced disorganized thinking, delusions, hallucinations, and abnormal movements.
A January 2018 article from Psychology Today discusses a patient with schizophrenia. The patient was known to run away from the hospital where he was seeking treatment for the condition. He had started using marijuana when he was 14 years old.
Studies on exactly how marijuana and schizophrenia could be linked are still needed. But there is now a lot of evidence supporting the relationship between marijuana and the condition.
- Suicidal ideation: A December 2018 study published by the Journal of Affective Disorders says that patients with depression who use marijuana on a frequent basis had worse mental health outcomes than patients who abstain from the drug. This resulted in suicidal ideation in many patients, and it decreased the likelihood that they would see psychiatric help.
An April 2017 article on VICE explains that in another study, people who smoke marijuana every day are at a higher than average risk of experiencing suicidal thoughts. Researchers involved in this study say they are unsure if people who are already suicidal turn to marijuana for comfort. They stress that the findings do not mean marijuana can cause suicidal thoughts in otherwise healthy people.
Can Marijuana Help Patients With Previous Mental Health Diagnoses?
In December 2018, the American Psychological Association (APA) published an article on how marijuana may still be able to help people with post-traumatic stress disorder (PTSD), anxiety, and pain. Studies on the effects of marijuana on these conditions show promise. 
As many as 94 percent of people with a card for medical marijuana in Colorado cited pain as the reason why they wanted medical marijuana. People with chronic pain may be able to use medical marijuana for relief instead of opioids.
APA also says that people who have cancer sometimes seek medical marijuana because of nausea caused by chemotherapy treatments. It has been confirmed that marijuana can help patients in this situation.
Marijuana is also being researched for its effects on PTSD. Right now, people who are diagnosed with PTSD are primarily treated with therapy, but this may not be wholly effective for everyone.
APA also says that studying medical marijuana is not easy. The hope is that more research is conducted so everyone can make good decisions when it comes to marijuana and their mental health.
Gender, Marijuana, And Mental Health
The Substance Abuse and Mental Health Services Administration (SAMHSA) released data in April 2014 that explored who uses marijuana and other drugs.
- Men use marijuana at higher rates than women.
- Adults who are 25 and older use marijuana at about the same rates regardless of sex.
- Men use marijuana at higher rates than women.
- Adults who are 25 and older use marijuana at about the same rates regardless of sex.
SAMHSA’s research does not mention whether sex or gender is likely to affect mental health repercussions as a result of marijuana consumption. Other organizations that research marijuana may come up with answers to this someday.
Their hope is that using this data can result in better care for women and men in various treatment settings and across age groups. It can instill more understanding about the way women and men use marijuana differently.
The Future Of Marijuana And Mental Health
While marijuana can potentially alleviate the symptoms of certain mental health disorders, it can trigger or exacerbate other mental health issues.
Ongoing research in the field will help to further illuminate exactly how marijuana affects mental health.
