Curious about cannabis? Here are six things you should know.

| October 25, 2023

With the legalization of cannabis (aka marijuana, weed, pot, etc.) in Maryland, the drug has gotten more attention. Cannabis refers to anything that contains delta-9 tetrahydrocannabinol or THC, the compound that produces a “high.” This compound and others are found in cannabis plants. There are many ways to use it, such as smoking, vaping, edibles, liquids, such as tea, and doing dabs.

Because cannabis is federally banned, it has been hard to research, so there are still some things we don’t fully understand. What we do know is that there are some considerable risks people may not know or consider when choosing to use cannabis.

In 2021, 2 in 3 people ages 18-25 did not use cannabis. As for Hopkins students, 76% of students did not use cannabis in the past year when asked about their use during the Spring 2023 Maryland Collaborative College Alcohol Survey. Whether you choose to use cannabis or not, it is important that the entire campus community has information about it to help reduce the amount and severity of the harm that could occur. So here are some things to know.

Cannabis affects your mental health.

Some people choose to use cannabis to cope with mental health problems, or to relieve stress. However, there is a catch. At lower doses, cannabis can help decrease symptoms of anxiety and depression but at higher doses, it can worsen anxiety. Cannabis has a biphasic effect, meaning there is a certain amount taken to experience a favorable effect. After that amount is reached, additional cannabis consumed causes negative effects.

For people who have anxiety, cannabis can increase your blood pressure and heart rate, which are the same physiological features a person living with anxiety can experience. This may cause concern and confusion, which then exacerbates anxiety. As people continue to use a substance, they build tolerance and then experience withdrawal. Withdrawal is the name for adverse effects a person feels when they stop using a substance they have used copiously and/or habitually. Nervousness or anxiety is the most reported withdrawal symptom for cannabis use at 74% and almost 60% experiencing depressed mood.

Cannabis has also been connected to schizophrenia, especially in young men, and has been theorized to contribute to contribute to 15% of schizophrenia cases.

Cannabis affects your sleep.

Sleep is an issue of concern for our students and trainees. With only so many hours in the day available, some students try to find ways (including cannabis) to fall asleep as soon as possible in the hopes of feeling more rested. Yet sometimes it becomes a question of quality rather than quantity.

Cannabis can affect sleep onset (ie, how quickly you fall asleep) for those who use low amounts and use infrequently. The caveat is that it can affect sleep quality, with daily or almost daily frequency of use. Some sleep disturbances associated with cannabis are:

  • trouble staying awake and falling asleep at appropriate times;
  • difficulty staying asleep; and
  • less time spent in rapid eye movement (REM) sleep , the restorative stage of sleep.

Some may argue that different strains of cannabis (like indica) are better for sleep, but the sleep disturbances are more associated with the level of THC and frequency of use.

Cannabis can negatively affect your digestive system.

One key consequence of cannabis use is increased hunger, colloquially called “the munchies.” Medical applications of cannabis include helping with conditions that have made it difficult to eat, like nausea from chemotherapy.

However, long-term habitual cannabis users can also experience digestive problems. Cannabis hyperemesis is a condition where a person experiences stomach issues such as stomach pains and random bouts of nausea and vomiting up to 20 times a day. Ironically, people sometimes increase the use of cannabis for this nausea when symptoms start to develop, which only progresses the disorder.

One way to manage cannabis hyperemesis is to take hot showers. Unfortunately, this often causes irritated, dry skin and the amount of time showering can interfere with daily activities. The only way to recover from cannabis hyperemesis is to abstain altogether, as use after a break or reduction can trigger symptoms again.

Cannabis affects your cognitive abilities.

Immediate and short-term effects of a single-time use of cannabis include impairments in memory, time perception, reaction time, and attention. These effects can last up to 24 hours after the time of initial use.

Research on long-term effects is emerging, particularly for people younger than 25 whose brains are still developing. But factors including the age of first use, amount of use, and frequency of use on developing brains have implications on how certain cognitive functions are negatively affected.

Memory, attention, and other cognitive functions have a relationship to academics, even in the short and medium term. Below is a graph showing how cannabis affects GPA with students who use cannabis having lower GPAs than students who don’t.

A bar graph titled “GPA by Past-year Cannabis Use, among JHU Students, 2018-2023” with the y axis labeled “Cumulative GPA” and the x axis labeled “Frequency Use During the past year” The Y axis shows a range starting at 0.00 and rising to 4.00. The X axis the following five categories, going from left to right: Never, Less than monthly, Monthly, Weekly, Daily.” 
The bars on the graph are all green.
The Never category has a cumulative GPA of 3.63.
The Less than Monthly category has a cumulative GPA of 3.58.
The Monthly category has a cumulative GPA of 3.53.
The Weekly category has a cumulative GPA of 3.43.
The Daily category has a cumulative GPA of 3.45.

Cannabis, even legal cannabis, always poses a risk.

Since the 1990s, the strength of THC in cannabis plants has grown 212%. There are also a variety of ways to use cannabis with products that can contain up to 90% THC. There are other compounds in cannabis plants, like cannabidiol (CBD), which is responsible for many of the benefits of cannabis, like help with sleep, pain, and mood management. THC does these things as well, but the effects diminish with long-term chronic use. However, with more THC in cannabis plants and products, some of the benefits people choose to use cannabis for may disappear quickly. And the negative effects may hit harder and faster.

This increase in THC has been linked to the negative harms of cannabis use, from acute signs of overdose or “green outs,” where people experience anxiety, panic attack, paranoia, hallucinations, racing heart, nausea, and vomiting. It has also been linked to the negative effects of long-term use, like impacts in brain function and development and cannabis hyperemesis.

The market is expanding more rapidly than regulatory bodies can keep up, and products with THC, CBD, and similar compounds from the cannabis plants are being sold without proper research and misleading marketing.

Cannabis can be habit-forming and even addictive.

Cannabis works on the brain the same way every other drug or behavior with the capacity of addiction does. It floods the brain with dopamine and other neurotransmitters like serotonin (which plays a role in mood, hunger, and sleep) and GABA (which plays a role in anxiety and learning).

As time goes on, the body’s reaction to cannabis is dulled, so people take more to have the same effect. The body stops making its own neurotransmitters and causes negative withdrawal symptoms. This change happens alongside other negative effects on the body, like the stomach or on the lungs if cannabis is smoked or vaped. Cannabis use disorder is a potential diagnosis for those whose health and lives have been negatively impacted by cannabis.

If you use cannabis and it’s playing a bigger role than you thought, or you are experiencing some of its harms, know that you have the option to reduce use and not quit altogether if you don’t want to. You can take a tolerance break (also known as a T-break) and note the changes in your physical and mental health.

However, the only way to completely avoid the harm is to abstain altogether.

There are resources for more information about cannabis, harm reduction, and resources for help such as the alcohol and other drug educator, eCHECKUP TO GO, and mental health services across the university.

Disclaimer: Research on cannabis sheds new light on the substance every day. This information is based on current but emerging information.