1

TEEN MARIJUANA USE 

WORSENS DEPRESSION

An Analysis of Recent Data Shows “Self-Medicating” 

Could Actually Make Things Worse

Millions of American teens* report experiencing weeks of hopelessness and loss of 

interest in normal daily activities, and many of these depressed teens are making 

the problem worse by using marijuana and other drugs. Some teens use marijuana 

to relieve the symptoms of depression (“self-medicate”), wrongly believing it may 

alleviate these depressed feelings. In surveys, teens often report using marijuana 

and other drugs not only to relieve symptoms of depression, but also to “feel good,” 

or “feel better,” to relieve stress, and help them cope.

However, recent studies show that marijuana and depression are a dangerous 

combination. In fact, using marijuana can worsen depression and lead to more 

serious mental health disorders, such as schizophrenia, anxiety, and even suicide. 

Weekly or more frequent use of marijuana doubles a teen’s risk of depression and 

anxiety. Depressed teens are more than twice as likely as their peers to abuse or 

become dependent on marijuana. 

Alarmingly, the majority of teens who report feeling depressed aren’t getting 

professional help. They have not seen or spoken to a medical doctor or other 

professional about their feelings. For parents, this means they need to pay closer 

attention to their teen’s behavior and mood swings, and recognize that marijuana 

and other drugs could be playing a dangerous role in their child’s life.

* In this report, references to “teens,” “youth,” and “children” include youth ages 12 to 17 unless otherwise noted.

1

 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Pg. 160. URL: http://www.oas.samhsa.gov/nsduh/2k6nsduh/2k6results.pdf. References to 

 “depression” and “depressed teens” in this report fall under the definition of Major Depressive Episode. Full definition can be found at the end of this report. 

2

 Patton, GC et al. Cannabis use and mental health in young people: cohort study. British Medical Journal, 325:1195-1198, 2002.

3

 2006 National Survey on Drug Use and Health, SAMHSA, 2007, Table 6.36B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTabs36to37.pdf. 4

 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Pg. 8. URL: http://www.oas.samhsa.gov/nsduh/2k6nsduh/2k6results.pdf.
2

Executive Summary

Two million teens report feelings of depression and loss of interest in 

daily activities during the past year.

Depressed teens are twice as likely as non-depressed teens to use 

marijuana and other illicit drugs. 

Depressed teens are more than twice as likely as their peers to abuse 

or become dependent on marijuana.

Using marijuana can cause depression and other mental illnesses.

Marijuana use can worsen depression and lead to more serious 

mental illnesses such as schizophrenia, anxiety, and even suicide.

Teens who smoke marijuana at least once a month are three times 

more likely to have suicidal thoughts than non-users.

The percentage of depressed teens is equal to the percentage 

of depressed adults, but depressed teens are more likely than 

depressed adults to use marijuana and other drugs. 

Teen girls who use marijuana daily are more likely than girls who do 

not use marijuana to develop depression.
3

Drugs and Depression

According to recent national surveys, two million 

youths (8%) felt depressed at some point in the 

course of a year.5 Another survey of high school 

students shows that percentage even higher (29%).6

There are indications that many teens are using 

drugs to “self-medicate” (deal with problems of 

depression and anxiety by using drugs to alleviate 

the symptoms). Many teens say they use drugs to 

“make them feel good” or “feel better.” 

However, research shows that using marijuana and 

other illicit drugs puts a teen at even greater risk for 

more serious mental illnesses. A teen who has been 

depressed at some point in the past year is more 

than twice as likely to have used marijuana (25%) 

as teens who have not reported being depressed 

(12%). Similarly, 35 percent of depressed teens used 

an illicit drug (including marijuana) during the year, 

compared to 18 percent of teens who did not report 

being depressed.7

Depressed teens are more likely to engage in other 

risky behaviors, as well. They are more likely than 

non-depressed teens to report daily cigarette use 

(5% vs. 3%) and heavy alcohol use (5% vs. 2%).8

5

 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Pg. 8. URL: http://www.oas.samhsa.gov/nsduh/2k6nsduh/2k6results.pdf. 6

 Youth Risk Behavior Surveillance System, 2005. Centers for Disease Control and Prevention, 2006. Pg. 9. URL: http://www.cdc.gov/mmwr/PDF/SS/SS5505.pdf.

 This survey defines depression as teens who felt so sad or hopeless almost every day for >2 weeks in a row that they stopped doing some usual activities.

7

 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Table 6.34B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTabs34to35.pdf. 8

 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Table 6.34B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTabs34to35.pdf.
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Link Between Marijuana Use, 

Depression, and Other Mental 

Health Problems

Teens who use marijuana can end up making 

tough times worse. Mental health risks associated 

with recent and long-term marijuana use include 

schizophrenia, other forms of psychosis, and even 

suicide. Recent research makes a strong case that 

cannabis smoking itself may be a causal agent in 

psychiatric symptoms, particularly schizophrenia.

Research shows that teens who smoke marijuana at 

least once a month in the past year are three times 

more likely to have suicidal thoughts than non-users 

during the same period.9

 Yet another study found 

that marijuana use was associated with depression, 

suicidal thoughts, and suicide attempts.10 One 

16-year study showed that individuals who were not 

depressed and then used marijuana were four times 

more likely to be depressed at follow up.11 Another 

study conducted over a 14-year period found 

that marijuana use was a predictor of later major 

depressive disorder.12 

An extensive analysis of longitudinal studies on 

marijuana use and risk of mental illness later in life 

showed that marijuana use increases the risk of 

developing mental disorders by 40 percent. The risk 

of psychosis increases with frequency of marijuana 

use, from 50 to 200 percent among frequent users. 

The authors conclude that “there is now sufficient 

evidence to warn young people that using cannabis 

could increase their risk of developing a psychotic 

illness later in life.”13 

Other studies also show a strong relationship 

between marijuana and schizophrenia. A study from 

New Zealand showed “a clear increase in rates 

of psychotic symptoms after the start of regular 

use” of marijuana.14 Another 21-year longitudinal 

study showed that marijuana use was associated 

with psychotic symptoms and suggested a causal 

relationship.15 A study published in Schizophrenia 

Research found that cannabis use seems to be a 

specific risk factor for future psychotic symptoms.16

Another study of young adults from birth to age 21 

found a relationship between early initiation and 

frequent use of cannabis and symptoms of anxiety 

and depression, regardless of a history of mental 

illness.17

Teens who smoke marijuana when feeling depressed 

are also more likely to become addicted to marijuana 

or other illicit drugs. Eight percent of depressed teens 

abused or became dependent on marijuana during 

the year they experienced depression, compared 

with only three percent of non-depressed teens.18 

Overall, more teens are in treatment for marijuana 

dependence than for any other illicit drug.19

9 Greenblatt, J. Adolescent self-reported behaviors and their association with marijuana use. Substance Abuse and Mental Health Services Administration (SAM

 HSA), 1998. URL: http://www.oas.samhsa.gov/NHSDA/Treatan/treana17.htm. 10 Fergusson, DM et al. Cannabis use and psychosocial adjustment in adolescence and young adulthood. Addiction 97:1123-1135, 2002. URL: http://www.chmeds.

 ac.nz/research/chds/publications/2002/adjustment.pdf. 11 Bovasso, GB. Cannabis abuse as a risk factor for depressive symptoms. The American Journal of Psychiatry, 158:2033-2037, 2001.

12 Brook, DW et al. Drug use and the risk of major depressive disorder, alcohol dependence, and substance use disorders. Archives of General Psychiatry, 

 59:1039-1044, 2002. URL: http://archpsyc.highwire.org/cgi/content/full/59/11/1039.

13 Moore, T et al. Cannabis use and risk of psychotic or affective mental health outcomes: a systemic review. The Lancet, Vol. 370: 319-328, 2007. 14 Fergusson, DM et al. Tests of causal linkages between cannabis use and psychotic symptoms. Addiction, 100, 3:354-366, 2005. URL: http://www.chmeds.ac.nz/

 research/chds/publications/2005/symptons.pdf. 15 Fergusson, DM et al. Cannabis dependence and psychotic symptoms in young people. Psychological Medicine, 33:15-21, 2003. URL: http://www.chmeds.ac.nz/

 research/chds/publications/2003/cannabis.pdf. 16 Ferdinand, RF et al. Cannabis--psychosis pathway independent of other types of psychopathology. Schizophrenia Research, 79(2-3):289-95, 2005.

17 Hayatbakhsh, MR et al. Cannabis and anxiety and depression in young adults: a large prospective study. Journal of the American Academy of Child and 

 Adolescent Psychiatry, 46(3):408-17, 2007.

18 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Table 6.36B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTabs36to37.pdf. 19 2005 Treatment Episode Data Set (TEDS), SAMHSA, 2008. URL: http://wwwdasis.samhsa.gov/webt/quicklink/US05.htm.
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Depressed Teens More Likely 

To Use Drugs than Depressed 

Adults

The percentage of teens reporting being depressed 

is similar to the percentage of adults reporting 

depression. Depressed teens, however, are more 

likely than depressed adults to use drugs. In the 

course of a year, seven percent of adults20 reported 

feeling depressed, compared to eight percent of 

teens.21

But a quarter (25%) of depressed teens used 

marijuana in the course of a year, while only 19 

percent of depressed adults did.22 Additionally, 35 

percent of depressed teens used other illicit drugs 

(including marijuana), compared to 28 percent of 

depressed adults.23

20 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Pg. 7. URL: http://www.oas.samhsa.gov/nsduh/2k6nsduh/2k6results.pdf. 21 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Pg. 8. URL: http://www.oas.samhsa.gov/nsduh/2k6nsduh/2k6results.pdf. 22 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Table 6.34B, 6.35B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTab

 s34to35.pdf. 23 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Table 6.34B, 6.35B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTab

 s34to35.pdf.
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Girls at Greater Risk

Teen girls are especially at risk. In fact, three times 

as many girls (12%) as boys (4%) experienced 

depression during the year.24 Another study confirms 

that girls are more likely than boys to report feelings 

of sadness or hopelessness (37% vs. 29%).25 

Substance abuse can compound the problem. 

Girls who smoke marijuana daily are significantly 

more likely to develop symptoms of depression and 

anxiety: their odds are more than five times higher 

than those of girls who do not smoke marijuana.26

24 2006 National Survey on Drug Use and Health, SAMHSA, 2007. Table 6.27B. URL: http://www.oas.samhsa.gov/NSDUH/2k6nsduh/tabs/Sect6peTabs27to33.pdf. 25 CDC Surveillance Summaries. June 2006) MMWR 55. Table 16. URL: http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5505a1.htm#tab16. 26 Patton, GC et al. Cannabis use and mental health in young people: cohort study. British Medical Journal, 325:1195-1198, 2002.
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Parental Involvement

Parents should not dismiss changes in their 

teen’s behavior as a “phase.” Their teen could be 

depressed, using drugs – or both. Parents can 

help their teen understand the risks of marijuana 

use, and should be on the lookout for signs of 

depression. 

It’s been shown that parents who make an effort to 

understand the pressures and influences on young 

people are more likely to keep their teen healthy and 

drug-free. 

Teens who report having conversations with their 

parents about alcohol and drug use are more likely 

to stay drug-free, compared to teens who do not talk 

about substance abuse with their parents.27

27 2006 National Survey on Drug Use and Health, SAMHSA, September 2007. URL: http://www.oas.samhsa.gov/nsduh/2k6nsduh/2k6results.pdf.

*Definition for MDE: A person was defined as having had a lifetime major depressive episode (MDE) if he or she had at least five or more of the following nine 

symptoms in the same 2-week period in his or her lifetime, in which at least one of the symptoms was a depressed mood or loss of interest or pleasure in daily 

activities: (1) depressed mood most of the day, nearly every day; (2) markedly diminished interest or pleasure in all or almost all activities most of the day, nearly 

every day; (3) significant weight loss when not dieting or weight gain or decrease or increase in appetite nearly every day; (4) insomnia or hypersomnia nearly 

every day; (5) psychomotor agitation or retardation nearly every day; (6) fatigue or loss of energy nearly every day; (7) feelings of worthlessness nearly every day; 

(8) diminished ability to think or concentrate or indecisiveness nearly every day; and (9) recurrent thoughts of death or recurrent suicide ideation. This definition is 

based on the definition found in the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (APA, 1994). A person was defined as having 

an MDE in the past year if he or she had a lifetime MDE and a period of time in the past 12 months when he or she felt depressed or lost interest or pleasure 

in daily activities for 2 weeks or longer, while also having some of the other symptoms defined above for a lifetime MDE. See Section B.4.5 of Appendix B for 

additional details.