What is marijuana, what are THC and CBD, and how do they affect the body and mind? A simple guide for families that explains it all, based on reliable medical sources.
Marijuana is one of the substances that raises the most questions in families. People talk about it at school, in the news and on social media, often with conflicting information: that it’s “natural,” that it “cures,” that it “doesn’t hurt anyone” or, on the contrary, that it’s the worst thing out there.
With this article, we’re opening a section of the Lumenia blog dedicated to marijuana and cannabis. Our goal is to explain, in plain language and based on reliable medical sources, what this plant is, what it contains and how it affects the body and mind. Learning about it without fear or prejudice is the first step toward supporting the people we love.
“Cannabis” and “marijuana” are used almost interchangeably. According to the U.S. National Institute on Drug Abuse (NIDA), the term refers to the dried leaves, flowers, stems and seeds of the Cannabis sativa plant. This plant contains at least 125 chemical compounds called cannabinoids.
Mayo Clinic adds that it’s also known as weed or pot, but that “cannabis” is the preferred name in medical settings.
Today, marijuana isn’t only smoked. NIDA describes several common forms:
An important fact for families: today’s marijuana is much stronger than it was a few decades ago. NIDA reports that between 1995 and 2022, the THC concentration in marijuana seized in the United States rose from about 4% to more than 16%, and some dispensary products exceed 40%. The higher the potency, the greater the risk of developing a use disorder.
Marijuana contains more than a hundred cannabinoids, but two are the best known: THC and CBD. Although they come from the same plant, they act very differently.
THC (delta-9-tetrahydrocannabinol). It’s the most abundant cannabinoid in the plant and the psychotropic or psychoactive component, meaning it’s responsible for the feeling of being “stoned” or high. NIDA explains that it temporarily alters mood, thoughts and perception. It’s also the component linked to the risk of addiction: the more THC a product has, the greater that risk, notes MedlinePlus, the health information service of the U.S. National Library of Medicine.
CBD (cannabidiol). It doesn’t produce a high. Today it’s sold in oils, gummies, supplements and creams. However, NIDA warns of three things worth knowing: it can cause side effects such as drowsiness, loss of appetite, vomiting or diarrhea; many products contain a different amount of CBD than the label states; and some products sold as “CBD” actually contain THC.
Mayo Clinic adds another warning: taking more than 300 milligrams of CBD a day can cause nausea, vomiting, diarrhea and even liver problems.
{% table %}
Table based on information from NIDA, Mayo Clinic and MedlinePlus.
An important point: the fact that there are approved medications made from these compounds doesn’t mean that smoking or eating marijuana is a treatment. NIDA clarifies that the FDA hasn’t approved any product containing the whole cannabis plant for medical use, and recommends talking to a doctor before using any cannabinoid product.
Mayo Clinic explains that there are three FDA-approved medications derived from cannabis: dronabinol and nabilone, prescribed for nausea and vomiting caused by chemotherapy (dronabinol is also used for loss of appetite), and Epidiolex, a purified form of CBD for seizures in rare childhood epilepsy syndromes such as Lennox-Gastaut and Dravet syndrome.
As for other uses, here’s what research shows according to Mayo Clinic:
Marijuana doesn’t affect everyone the same way. According to NIDA and MedlinePlus, its effects depend on the amount and potency of the product, how it’s used, the person’s age, sex and genetics, other substances or medications being taken, and the person’s prior experience.
While under its effects, a person may experience:
Mayo Clinic explains that marijuana slows communication between the brain and spinal cord, and adds other common effects: red, dry eyes, dry mouth, headache, fatigue, drowsiness and dizziness, with a higher risk of falls. That’s why it recommends not driving or operating machinery after using it.
With high doses, very potent products or in people with little experience, NIDA notes that anxiety, fear, distrust, panic attacks and even hallucinations are more common. MedlinePlus adds that a cannabis overdose is possible and shows up as anxiety, panic and a rapid heartbeat.
Watch out for children at home: edibles such as gummies or baked goods can be mistaken for candy. NIDA reports that accidental poisonings in children are a growing concern and can lead to hospitalization.
Frequent, long-term use, especially of high-THC products, is linked to several health problems. These are the main ones described by NIDA and MedlinePlus:
Mayo Clinic adds some important details about mental health: frequent use can increase the risk of depression or worsen its symptoms, and in people with bipolar disorder it can trigger manic episodes (irritability, restlessness and racing thoughts). For this reason, it recommends that people with heart disease, a mental health condition or a history of substance use avoid marijuana.
Mayo Clinic warns that marijuana can interact with other substances and medications:
If someone at home takes medication and uses marijuana, it’s worth discussing it with their doctor or pharmacist.
Yes. NIDA estimates that between 22% and 30% of people who use marijuana have a cannabis use disorder. The biggest risk factor is how often it’s used; starting at a young age, how long someone has been using and family history also play a role.
Mayo Clinic puts it simply: it’s considered a cannabis use disorder when marijuana starts causing problems in daily life, such as at work, at school or at home.
When they stop, some people experience withdrawal symptoms such as irritability, anxiety, insomnia, vivid dreams, reduced appetite and strong cravings. The good news is that treatment exists: NIDA notes that therapies such as cognitive behavioral therapy, motivational enhancement therapy and contingency management are effective.
“It’s natural, so it’s harmless.” Coming from a plant doesn’t make something safe. As we’ve seen, THC can affect the brain, heart, lungs and mental health.
“Marijuana isn’t addictive.” False. Between one in four and one in three people who use it develop a use disorder, according to NIDA’s estimates.
“It’s the same marijuana as before.” No. THC potency has multiplied in recent decades, and so have the risks.
“CBD is the same as medical marijuana and it’s completely safe.” CBD doesn’t produce a high, but it has side effects, its labels aren’t always reliable and some products contain THC.
The medical criteria NIDA cites for cannabis use disorder help recognize when use is no longer under control. Some signs are:
If you recognize several of these signs in yourself or someone you love, this isn’t a time for blame, but for seeking professional guidance.
Understanding what marijuana is and how it works is the first step toward talking about it at home calmly and without prejudice. In upcoming articles in this section, we’ll dive deeper into topics such as marijuana use in teens, CBD and how to support a family member who uses.
At Fundación Lumenia, we support people and families living with the disease of addiction, combining science with the experience of those of us who have already walked the path of recovery. If you have questions or are worried about someone you love, message us on WhatsApp at +52 81 1805 4988 or email hola@lumenia.org.
Just for today, I work on myself, and I deserve to live, not just survive.
This article is for informational purposes only and is not a substitute for evaluation by a health professional.
Many parents silently ask, “Where did I go wrong?” Here’s what research says about the causes of addiction, the difference between guilt and responsibility, and what you can actually do today.
How are painful childhood experiences linked to addiction? We explain what the research says and why trauma and substance use should be treated together.
What do parents go through when their teenage child develops an addiction? We summarize a study that identified eight shared experiences, from the first signs to the decision to seek help.
Confidential consultation
If you’re worried about yourself or someone you love, call us. We’ll listen without judgment and guide you through the next steps. The call is confidential and comes with no obligation.
