Cannabis is legal for adults in many states, and legal does not mean risk free. Cannabis use disorder is a recognized diagnosis, cannabis withdrawal is a recognized syndrome, and today’s products bear little resemblance to what was available a generation ago. Federal scheduling also changed in 2026.
Quick reference
| Drug class | Cannabinoid. THC is a partial agonist at CB1 receptors |
|---|---|
| Federal scheduling as of 2026 | FDA approved marijuana products and state licensed medical marijuana moved to Schedule III effective April 28, 2026. Recreational marijuana outside those categories remains Schedule I |
| Potency shift | 1990s flower typically under 5 percent THC. Modern dispensary flower commonly 15 to 25 percent. Concentrates can exceed 80 to 90 percent |
| Prevalence of the disorder | Roughly 3 in 10 people who use cannabis develop some degree of cannabis use disorder |
| Is withdrawal dangerous? | No, but uncomfortable enough to sustain daily use |
| Withdrawal timing | Begins within 24 to 72 hours, peaks around days two to six, mostly resolves in one to three weeks |
| Distinctive complication | Cannabinoid hyperemesis syndrome, cyclic vomiting relieved temporarily by hot showers |
| Detection window | Occasional use, three to seven days in urine. Daily heavy use, commonly three to six weeks |
The 2026 scheduling change
On April 22, 2026 the Department of Justice signed a final order moving FDA approved marijuana products and marijuana handled under state licensed medical programs from Schedule I to Schedule III, effective April 28, 2026. Recreational marijuana outside those categories remains Schedule I. A further administrative hearing on broader rescheduling, including adult use marijuana, was held between June 29 and July 15, 2026.
Rescheduling changes research access, tax treatment and some regulatory obligations. It does not change the pharmacology, and it does not reduce the dependence or psychosis risk described below.
Why potency changed the risk profile
As THC content has risen, CBD content in high THC cultivars has fallen. CBD appears to buffer some of the anxiety and psychosis promoting effects of THC, so modern products deliver more of the risky compound alongside less of the moderating one. Clinicians now routinely see presentations that were rare a generation ago: severe dependence, cannabis induced psychosis, hyperemesis syndrome and pronounced withdrawal.
What cannabis withdrawal involves
Irritability, anger and aggression; anxiety and restlessness; insomnia with unusually vivid unpleasant dreams, which many people find the hardest symptom; decreased appetite and weight loss; depressed mood; and physical symptoms including headache, sweating, chills, stomach pain and tremor. Because THC is stored in fat and released slowly, withdrawal from heavy use has a longer tail than most people expect.
Mental health risks
- Psychosis. There is a dose response relationship between cannabis use, particularly high potency products and daily use, and risk of psychotic disorders. Risk is greatest in adolescents and people with a family history.
- Anxiety and panic, common with high THC products and paradoxical for people using cannabis to manage anxiety.
- Adolescent brain development. Regular use before the mid twenties is associated with impaired learning and memory and lower educational attainment.
- Bipolar disorder. Cannabis can trigger manic episodes and worsen the illness course.
Cannabinoid hyperemesis syndrome
CHS produces cycles of severe vomiting and abdominal pain in long term heavy users, characteristically relieved temporarily by hot showers. Patients often spend years undiagnosed, cycling through emergency departments and abdominal imaging. Anti nausea medication does not reliably help. The only dependable treatment is stopping cannabis, after which symptoms typically resolve over weeks. If the hot shower pattern describes you, mention CHS by name to your physician.
Other risks worth knowing
Chronic bronchitis and cough from smoking. Acute increases in heart rate and elevated heart attack risk in the hour after use. Measurably impaired driving, with roughly double the crash risk, and far worse combined with alcohol. Edibles have a delayed onset of one to two hours which leads to overconsumption and a large share of cannabis emergency visits, including in children who find them. THC crosses the placenta and enters breast milk and is not recommended in pregnancy, including for morning sickness.
Treatment
No medication is FDA approved. Cognitive behavioral therapy combined with motivational enhancement therapy is the best studied approach, and contingency management adds meaningfully to it. For adolescents, family based treatments including Multidimensional Family Therapy have the strongest evidence. Most heavy users are managing anxiety, insomnia, PTSD, ADHD or pain with cannabis, and removing it without treating the underlying condition usually fails.
Common questions
Is marijuana actually addictive?
Yes. Cannabis use disorder is in the DSM-5-TR, cannabis withdrawal is a recognized syndrome, and roughly 3 in 10 users develop some degree of the disorder. It lacks the overdose risk of opioids and the withdrawal danger of alcohol, and it can still become compulsive and life narrowing.
Is marijuana legal now that it is Schedule III?
No. Rescheduling is not legalization. Only FDA approved products and marijuana under state licensed medical programs moved to Schedule III. Recreational marijuana outside those categories remains Schedule I federally, whatever state law says.
Why do I vomit for days and only hot showers help?
That pattern strongly suggests cannabinoid hyperemesis syndrome. Stopping cannabis resolves it, usually over a few weeks. See a physician to exclude other causes and mention CHS specifically, because it is frequently missed.
Is medical marijuana different from recreational?
Same compounds, same risks. There is reasonable evidence for cannabis in a handful of conditions, and a dispensary recommendation does not change the dependence or psychosis risk.
Sources
- Federal Register, Schedules of Controlled Substances: Rescheduling of Marijuana, April 2026
- DEA, marijuana rescheduling regulatory actions
- National Institute on Drug Abuse, cannabis research report
- DSM-5-TR, cannabis use disorder and cannabis withdrawal criteria
Need help now? In an emergency call 911. If you are in crisis or thinking about suicide, call or text 988 (Suicide and Crisis Lifeline; veterans press 1). For free, confidential treatment referrals 24 hours a day, call the SAMHSA National Helpline at 1-800-662-4357. You can also search licensed programs at FindTreatment.gov, or use our rehab directory and state listings.
Addiction Now publishes health journalism and reference material. This page is not medical advice, a diagnosis, or a treatment plan. Do not stop a prescribed medication without talking to a clinician. Withdrawal from alcohol, benzodiazepines and barbiturates can cause seizures and can be fatal without medical supervision.
Related reference pages
Reviewed and updated July 30, 2026 by the Addiction Now editorial team. Figures cited come from the CDC, NIDA, SAMHSA and the FDA.
