Marijuana Symptoms of Use

You can recognize marijuana use by looking for physical and behavioral changes. The drug can cause red eyes, mood swings and reduced energy. Long-term cannabis use can also cause work, school or relationship problems.

Topics On this page
| | 14 sources
Section Menu

Marijuana is the most popular illicit drug in the United States. Americans use the controversial substance for both medical and recreational purposes each day. While many people smoke cannabis for its euphoric properties, using the drug recreationally can lead to marijuana addiction and other health problems.

To identify signs and symptoms of marijuana use in your child or another person you care about, pay attention to changes in appearance or behavior. You can also look for drug paraphernalia, changes in friends or problems at school or work.

Signs of Marijuana Use

Cannabis use can be difficult to recognize. But people who use the drug exhibit a number of physical, psychological and behavioral changes.

Behavioral signs of marijuana use include:
  • Loud talking and laughter
  • Mood swings
  • Irritability
  • Low energy levels
  • Reduced activity
  • Forgetfulness
  • Defensiveness and secretiveness
  • Self-centeredness

People who smoke marijuana tend to spend time together. If your loved one is hanging around individuals who use cannabis, then he or she may be influenced to use the drug. Parents should make sure their children know about peer pressure and how to say no when they’re offered drugs or alcohol.

Neglected Appearance

According to the Drug Enforcement Administration, people who abuse marijuana often neglect their hygiene. Marijuana users might also have green, tar-like stains on their clothes.

Their breath, hair, clothes or vehicle may also smell like marijuana, which has an odor similar to burning rope. To mask this stench, some people use air fresheners, breath mints or heavy amounts of cologne.

Problems at School or Work

Chronic marijuana use can also cause problems at school or work. Adolescents who use marijuana often have poor grades because they are frequently absent or lack the motivation to perform well. Cannabis use can also cause learning problems, which can affect a student’s academic standing.

Adult marijuana users might have trouble performing tasks at work. They may have difficulty concentrating, showing up on time or communicating with co-workers. People can lose their jobs over these issues, which may result in financial problems or, in extreme cases, homelessness.

Drug Paraphernalia

A variety of devices and products can be used to smoke marijuana, ranging from cigar wraps to hookah pipes.

Marijuana paraphernalia includes:
  • Bongs
  • Rolling papers
  • Cigars
  • E-cigarettes (used to smoke cannabis concentrates)
  • Pipes
  • Metal clips

Marijuana is a Schedule I drug, which means it is illegal to possess in the United States. As a result, many people go to great lengths to conceal their cannabis use. Individuals often hide their drug paraphernalia in their clothes, underneath their bed or in their car.

Mental Health Problems

One long-term effect of marijuana use is depression, a mental condition characterized by depressed mood and lack of interest in everyday activities. Cannabis can also lead to more severe mental problems, including schizophrenia.

A 2014 report by the DEA found that depressed teens are twice as likely as their peers who are not depressed to abuse marijuana or become dependent on the drug. Research has also shown that marijuana use can worsen symptoms of depression and lead to suicidal thoughts.

Symptoms of Marijuana Use

Marijuana can make people feel euphoric, excited or relaxed. They may also experience distressing effects shortly after use, including anxiety, hangovers or headaches.

Short-term symptoms of marijuana use include:
  • Anxiety
  • Dry mouth and throat
  • Reduced appetite
  • Paranoia
  • Restlessness
  • Sleep problems
  • Decreased concentration, alertness and reaction time
  • Changes in sensory perception
  • Impaired thinking
  • Blackouts and memory loss

Smoking marijuana causes a high that generally lasts two to three hours, with the peak effects occurring 10 to 30 minutes after use. But research has shown that smoking one joint impairs driving skills, such as concentration and coordination, for at least four to six hours.

It is possible to overdose on marijuana. An overdose is not limited to taking lethal amounts of a drug. It can occur when someone experiences serious side effects that require immediate medical attention. People who overdose on cannabis can experience paranoia, panic or acute psychosis, especially if they are new users or already have a mental health condition.

An overdose can also occur when people smoke marijuana that is laced with hallucinogens or other dangerous drugs. This can cause more severe side effects, such as heart attack, seizure or stroke.

Long-term cannabis use can cause health effects that linger for years. Marijuana abuse can damage the lungs, cause paranoia and worsen symptoms of schizophrenia. It can also impede brain development in adolescents and lower a person’s IQ.

Some heavy, long-term marijuana users experience cannabinoid hyperemesis syndrome, a condition associated with cycles of nausea and vomiting. People can often relieve the nausea and other symptoms by taking a hot bath.

Signs of Marijuana Addiction

Repeated cannabis use can lead to a substance use disorder, which can range from mild to severe. Addiction is a severe substance use disorder characterized by erratic behavior and compulsive drug-seeking.

The view that marijuana causes addiction has sparked controversy. Many advocates for legalizing the drug believe that it isn’t addictive. However, the California Society of Addiction Medicine states that neuroscience, animal studies and clinical reports of human experiences have indicated that marijuana can cause addiction.

Signs of marijuana addiction include:
  • Struggling to stop using the drug regularly
  • Stealing money to purchase weed
  • Using marijuana to deal with problems
  • Having strong cravings to use
  • Experiencing marijuana withdrawal symptoms upon stopping use

Many individuals who abuse the drug have a mild cannabis use disorder, also called dependence. Dependence occurs when the brain adapts to the drug. People who are dependent on marijuana experience uncomfortable withdrawal symptoms when they quit, but they might not act compulsively or display other trademark signs of addiction.

Treating a Marijuana Use Disorder

Knowing the signs of marijuana use and the immediate effects can help you understand the consequences of abusing the drug. If a loved one exhibits several of these traits, consider having a conversation about the dangers of cannabis. If that doesn’t convince the person to quit, an intervention might.

Treatment for marijuana addiction can assist people in overcoming a substance use disorder. Treatment plans are catered to meet the client’s specific needs. Many people have overcome their problems with marijuana abuse by attending a rehab facility.

According to the National Institute on Drug Abuse, behavioral therapies have shown promise for treating a marijuana use disorder. These treatments include cognitive behavioral therapy, contingency management and motivational enhancement therapy. Benzodiazepines such as Valium can be used treat a cannabis overdose.

Marijuana use is closely associated with mental illness, such as depression or post-traumatic stress disorder. If a person has co-occurring disorders, both the addiction and the mental illness must be treated to achieve full recovery.

If you think your loved one may be abusing cannabis, contact a marijuana hotline. These services can help you recognize signs and symptoms of marijuana dependence, and many of them operate 24/7. They can also provide a list of nearby rehab facilities that treat marijuana addiction.

Medical Disclaimer: aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.

Matt Gonzales
Content Writer,
Matt Gonzales is a writer and researcher for He graduated with a degree in journalism from East Carolina University and began his professional writing career in 2011. Matt covers the latest drug trends and shares inspirational stories of people who have overcome addiction. Certified by the Centers for Disease Control and Prevention in health literacy, Matt leverages his experience in addiction research to provide hope to those struggling with substance use disorders.

View Sources

Ready to make a change?

Get cost-effective, quality addiction care that truly works.

Start Your Recovery
We're here to help you or your loved one.
Question mark symbol icon

Who am I calling?

Calls will be answered by a qualified admissions representative with Advanced Recovery Systems (ARS), the owners of We look forward to helping you!

Question mark symbol icon

Who am I calling?

Phone calls to treatment center listings not associated with ARS will go directly to those centers. and ARS are not responsible for those calls.