Although many people associate marijuana use with mellow, calm, and even “lazy” effects, for some people, it can act as a stimulant. Increasing energy, alertness, and anxiety.
Cannabis has a complex compound profile that, depending on the strain, dose, and individual factors of a person, can produce a range of depressive, stimulative, or hallucinogenic effects on the brain.
Regardless of the short-term effects one experiences using cannabis, long-term use carries similar risks, such as memory loss, shortened attention span, and increased risk of mental health problems like depression or anxiety.
Read on to learn more about the effects of cannabis and how seeking treatment can support your brain health and improve overall quality of life.
What Is A Stimulant? Understanding Drug Types
A stimulant is a type of drug known for stimulating activity in the central nervous system to increase alertness and energy. Drug types are typically categorized based on their effect profiles and properties, and usually fall into one of 7 drug classes [1]:
- Central Nervous System (CNS) Stimulants: Elevate mood, increase energy, and focus. These include cocaine, methamphetamine, and prescription medication for ADHD, such as Adderall.
- Central Nervous System (CNS) Depressants: These reduce activity in the central nervous system and slow down brain function. Examples include alcohol, benzos (Xanax), and OTC medications such as Benadryl.
- Hallucinogens: These are psychedelic drugs that alter your perception of the senses and reality by impacting communication pathways between nerve cells in the brain. Examples include LSD, psilocybin, and MDMA.
- Dissociative Anesthetics: These distort perceptions of sight and sound and produce feelings of detachment from the environment and self. Common examples include ketamine, phencyclidine (PCP), and dextromethorphan (DXM). They act primarily by disrupting communication between nerve cells in the brain, inducing dissociative states that can lead to hallucinations and out-of-body experiences.
- Narcotic Analgesics: Also known as opioids, these drugs are used medically to relieve pain but have high potential for misuse and dependence. Examples include heroin, morphine, oxycodone, and fentanyl. They act on opioid receptors in the brain to produce pain relief and, often, feelings of euphoria.
- Inhalants: These are volatile substances that produce chemical vapors inhaled to induce psychoactive or mind-altering effects. Common inhalants include glue, paint thinners, and nitrous oxide. Inhalants depress the central nervous system, resulting in effects ranging from dizziness to unconsciousness.
- Cannabis: Psychoactive drug from the Cannabis plant used primarily for medical or recreational purposes. The main active compounds, THC and CBD, interact with cannabinoid receptors in the brain, affecting mood, perception, and cognition. Effects include relaxation, altered sensory perception, and, in some cases, anxiety or paranoia.
Marijuana’s Complex Effects: Stimulant, Depressant, or Hallucinogen?
Cannabis is a psychoactive drug and a Schedule 1 controlled substance with properties that can overlap with stimulants, depressants, and hallucinogens. This is due to the diverse effects of its active chemical compounds, THC and CBD.
Weed As A Stimulant
Although people often think of cannabis as a depressant, making you feel sleepy or relaxed, for some, weed can act like a stimulant by increasing heart rate, mood, and boosting energy. This is partially due to the active chemical in weed, THC, which activates the sympathetic nervous system [2].
Strains with higher rates of THC and certain terpene profiles (the unique natural aromatic compounds that give cannabis strains their distinct flavors and smells) with fruity or citrusy aromas are usually associated with more uplifting or energizing effects, although this is not the case for everyone, and you can’t truly predict what kind of experience you will have with cannabis [3].
Common stimulant effects of cannabis include euphoria, heightened sensory perception, increased talkativeness, restlessness, and anxiety. These effects are typically much milder compared to classic stimulants like cocaine or amphetamines.
Weed As A Depressant
Weed is most commonly experienced as a depressant, with effects that slow the nervous system and brain function. For this reason, many users report using cannabis to calm nerves, relax tense muscles, and treat conditions like insomnia, anxiety, and muscle spasms [4].
Many individuals who use weed as a depressant for things such as sleep or appetite become dependent on it. And the depressant effects of weed can cause several short-term, distressing side effects that include:
- Nausea or vomiting
- Dizziness/blurred vision
- Slowed breathing
- Slurred speech
- Reduced motor skills and coordination
- Short-term memory loss
Weed As A Hallucinogen
Weed rarely causes actual visual hallucinations as are sometimes portrayed in movies and cartoons. However, symptoms such as changes in sensory perception and time distortion are typical effects of hallucinogens such as LSD or MDMA.
Some of the hallucinogenic effects caused by weed include:
- Impacted sense of time or space
- Reduced motor skills
- Nausea
- Dry mouth
- Detachment from reality or self
The Long-Term Effects of Marijuana on the Brain
Regardless of whether cannabis acts as a stimulant, depressant, or hallucinogen, the long-term effects of cannabis on the brain are similar because of how THC and CBD affect the endocannabinoid system (ECS).
The ECS is a network of cannabis receptors located throughout the body that bind to the cannabinoids THC and CBD, located in the nervous system and regions of the brain such as the hippocampus and amygdala. These help regulate other neurotransmitters, impacting functions such as hunger, attention, mood, emotional regulation, and memory [5].
Mood and Energy Levels
Long-term cannabis use can impact mood by altering activity in brain regions involved in emotional processing, such as the orbitofrontal cortex and amygdala. Regular cannabis users often experience increased risks of anxiety, depression, and mood instability.
THC’s impact on dopamine release in reward circuits can also result in reduced motivation and anhedonia (reduced ability to feel pleasure), contributing to decreased energy and engagement [6].
Memory, Attention, and Learning
According to one study, regular cannabis use is linked to structural changes in the brain, such as reduced hippocampal volume, which affects both long and short-term memory [7].
Long-term users also show deficits in attention, working memory, and verbal learning. Teens and young adults are especially vulnerable to this due to ongoing brain development.
Nervous System and Sensory Perception
Neuroimaging studies reveal negatively altered connectivity in brain networks regulating sensory integration and executive function in chronic cannabis users [8].
Cannabis also impacts the nervous system by disrupting endocannabinoid regulation of neurotransmitters such as GABA and glutamate. These alter sensory perception, motor coordination, and pain processing.
Routine, Habit, and Addiction
Long-term cannabis use can lead to cannabis use disorder (CUD), characterized by compulsive use despite negative consequences. Effects on the brain’s reward system, particularly in the nucleus accumbens, reinforce habits and routines.
Functional imaging shows increased brain response to cannabis cues in users with CUD, indicating neurological conditioning and cravings. Withdrawal symptoms such as irritability, anxiety, and sleep disturbances contribute to this addictive cycle [7].
Integrative Dual Diagnosis Treatment in Kansas
Treating Cannabis Use Disorder effectively means addressing the neurobiological effects of marijuana on the brain as well as addressing any co-occurring mental health challenges, emotional distress, or trauma that drives cannabis use.
At Avalon Wellness & Recovery, we offer whole-person care using somatic therapies, nervous system regulation, and mindful practices designed to help clients reconnect with their bodies and reduce cravings for drugs and alcohol. Our wellness services, such as infrared sauna, steam rooms, and cold plunge therapy, can ease symptoms of withdrawal such as anxiety, nausea, and sleep difficulties.
Contact our admissions team today to discover how Avalon’s integrative approach to substance use, mental health, and trauma recovery can support you or a loved one to live a cannabis free lifestyle.
Sources
[1] Baconi, D. L. (2023). Understanding the Mechanisms of Action and Effects of Drugs of Abuse. Molecules (Basel, Switzerland), 28(13), 4969.
[2] de Wit, H. (2022). Acute effects of oral delta-9-tetrahydrocannabinol (THC) on autonomic cardiac activity and their relation to subjective and anxiogenic effects. Psychophysiology, 59(2), e13955.
[3] Jantrawut, P. (2020). The Cannabis Terpenes. Molecules (Basel, Switzerland), 25(24), 5792.
[4] Pérez, J. et al. 2025. CANNABINOIDS FOR ANXIETY AND SLEEP DISTURBANCES: A SCOPING REVIEW. Karger.
[5] Grinspoon, P. 2021. The endocannabinoid system: Essential and mysterious. Harvard Health.
[6] Gonzalez, R. et al. (2018). Nonacute effects of cannabis use on motivation and reward sensitivity in humans: A systematic review. Psychology of addictive behaviors: journal of the Society of Psychologists in Addictive Behaviors, 32(5), 497–507.
[7] London, D. et al. (2019). Cannabis effects on brain structure, function, and cognition: considerations for medical uses of cannabis and its derivatives. The American journal of drug and alcohol abuse, 45(6), 563–579.
[8] Sutherland, M. T. (2018). Neuroimaging meta-analysis of cannabis use studies reveals convergent functional alterations in brain regions supporting cognitive control and reward processing. Journal of psychopharmacology (Oxford, England), 32(3), 283–295.