The honest version of this topic is narrower than either side of the argument allows. Some evidence has linked cannabis use to earlier onset of psychosis in people with genetic risk factors for psychotic disorders, including schizophrenia, as well as worse symptoms in people who already have these conditions [1]. Two qualifiers sit in the first half of that sentence. Earlier onset. And people who already carry genetic risk. The second half carries no qualifier at all, and it is the half most readers of this page are in.
Psychosis itself refers to a collection of symptoms that affect the mind, where there has been some loss of contact with reality [2]. Possible causes include sleep deprivation, certain prescription medications, and the misuse of alcohol or drugs [2]. So an episode in a heavy cannabis user is a real clinical event. It needs assessment now. The explanation can come later.
This page covers five things. Why the which-came-first question is so hard here. How the two problems hold each other in place. What an assessment looks at. What treatment does at each level. And what aftercare has to carry. Our hub on co-occurring disorders covers the wider territory.
Which came first, and why the answer matters less than people think
Here the causal question is the most contested in this category. It is also the least useful in a treatment room.
The evidence supports a link to earlier onset in people who already carry genetic risk, and to worse symptoms in people who already have one of these conditions [1]. NIDA adds that the association between heavy cannabis use and schizophrenia has been found to be especially strong in young males compared to females [1]. The evidence does not stop with people who already carry risk. NIDA also reports that cannabis use at a young age has been linked to the likelihood of developing psychosis [1]. A link is not a cause, and this page does not claim one.
There is a second complication. Cannabis use is common among people who later develop a psychotic illness. Part of the reason is plain. Early signs include suspiciousness, paranoid ideas or uneasiness with others, and withdrawing socially and spending a lot more time alone [2]. Those feelings are miserable. Anything that mutes them for an evening gets used.
None of that changes the first move. With early diagnosis and appropriate treatment, it is possible to recover from psychosis [2]. Reducing the duration of untreated psychosis is critical [2]. That is a reason to book an assessment now, not to argue about cause.
How psychosis and substance use reinforce each other
Through symptom relief that costs more than it gives.
Regular use carries its own costs. Studies have estimated that 22% to 30% of people who use cannabis have cannabis use disorder [1]. That share is higher than most people expect. Regular, heavy use in adolescence is associated with negative effects on working memory, processing speed, verbal memory and academic functioning [1]. Those effects land on the same faculties the illness is already taxing.
Stopping is not free either. Withdrawal symptoms may include anger, irritability, aggression, feeling nervous or anxious, restlessness, decreased appetite or weight, depression and insomnia [1]. Look at two items on that list. Anxiety and insomnia both look like the illness getting worse. Both are also the most likely reason someone goes back to using.
There is a third route, and NIDA describes it for the whole category. Substance use can lead to changes in some of the same brain areas that are disrupted in other mental disorders, such as schizophrenia, anxiety, mood, or impulse-control disorders [3].
If someone is a danger to themselves or others, is unresponsive or has trouble breathing, call 911. For a mental health crisis, or for thoughts of suicide, call or text 988.
Getting an assessment in Georgia
Promises Atlanta, in Dacula, Georgia, publishes medical detox, residential rehab and aftercare planning, and describes itself as a place for people with substance use disorders and co-occurring mental health conditions. Mention any psychiatric symptoms on the first call, because they change which level of care is appropriate.
See treatment options in Georgia
Verify your insurance
Promises Atlanta is part of our family of treatment centers. See the Promises Atlanta campus.
Why treating one without the other usually fails
Because the clock is running on one of them.
Early treatment often means better recovery, and reducing the duration of untreated psychosis is critical [2]. Treat the cannabis use first and get to the psychiatric symptoms later, and you spend the one resource that matters most here. That resource is time.
The reverse failure is just as real. Treating the illness while heavy use continues means aiming at a moving target. The substance keeps changing the same brain systems the treatment is aimed at [3].
NIDA states the sensible arrangement plainly. It is usually better to treat these health issues at the same time rather than separately, and research suggests that this can make all the treatments more effective [3]. Integrated care combines mental health and substance use treatment so patients can receive more convenient, coordinated care [4].
Assessment: separating substance-induced symptoms from an independent disorder
This takes weeks, not an afternoon. The plan goes ahead while it happens.
Accurate diagnosis is key for treating co-occurring substance use and mental disorders, since symptoms may overlap [4]. Here the overlap is stark. NIMH lists the misuse of alcohol or drugs among the possible causes of psychosis [2]. NIDA adds that cannabis intoxication can also induce a temporary psychotic episode in some people, especially at high doses, and that experiencing such an episode may be linked with developing a psychotic disorder later in life [1]. So the clinical question is simple to state. Do the symptoms clear as the substance clears, or do they stay once it has gone?
That is why nobody responsible gives a firm diagnosis in week one. Clinicians treat what is in front of them. They watch over time. They revise the diagnosis as the picture settles. Treatment of psychosis usually includes antipsychotic medication [2], and it does not wait for the causal question.
Physical withdrawal is not the main risk here, but it is not nothing. Anger, irritability, aggression, restlessness, anxiety and insomnia are all on the withdrawal list [1]. Agitation in someone who is also unwell in this way needs medical supervision, not a spare room.
If someone is a danger to themselves or others, is unresponsive or has trouble breathing, call 911. For a mental health crisis, or for thoughts of suicide, call or text 988.
Our explainers on medical detox and withdrawal symptoms describe what supervision involves.
Integrated dual diagnosis treatment, level by level
The psychiatric side sets the level of care here. The substance side does not.
Someone in an acute episode needs a setting that can manage it safely. An ordinary substance use program may not be that setting. Our own guide to getting into rehab says the first call may ask about mental health history and about any co-occurring disorders. An honest answer there saves a wasted journey.
Inpatient rehab is where one team can hold both plans while an episode is acute. That is the integrated care NIMH describes, delivered in one place [4]. NIMH calls coordinated specialty care a multi-element, recovery-oriented team approach to treating psychosis [2]. That team framing is the thing to look for when comparing options.
Step-down and outpatient care is where the medication is watched over months. The substance use work runs alongside it. Our guide to levels of care explains how the rungs relate.
Medication considerations when both are present
Antipsychotic medication is on one side of this plan, and there is nothing equivalent on the other.
Treatment of psychosis usually includes antipsychotic medication [2]. Cannabis use disorder has no approved medication in that sense. The evidence there sits with behavioral interventions such as cognitive behavioral therapy, motivational enhancement therapy and contingency management [1]. So one half of the plan has a drug anchor and the other half does not.
This page gives no doses, no schedules and no comparison between medications. Those belong to a prescriber who has examined the person. A co-occurring plan may include medications, psychosocial interventions, or a combination, depending on the needs of the individual and the substances involved [3].
The practical warning is about stopping. NIMH’s advice is to talk with a health care provider about side effects, medication costs and dosage preferences, such as a daily pill or a monthly injection [2]. Stopping is a decision to make with the prescriber rather than alone. Our page on medication assisted treatment covers how medication and therapy fit together.
Therapies with evidence for co-occurring presentations
Two evidence bases, and they are compatible.
For cannabis use disorder, behavioral interventions such as cognitive behavioral therapy, motivational enhancement therapy and contingency management can be effective [1]. For co-occurring presentations generally, cognitive behavioral therapy, contingency management and motivational interviewing can help individuals build coping skills [4], and family-based interventions such as Multisystemic Therapy and Functional Family Therapy can be particularly effective [4]. On the psychosis side, individual or group psychotherapy is tailored to a person’s recovery goals [2].
The overlap between those lists is not an accident. One therapist can often work on both halves at once. They have to know about both halves first.
Our overviews of substance abuse counseling techniques and dialectical behavior therapy describe what those sessions involve.
Relapse risk and what aftercare needs to cover
Two kinds of relapse, and they trigger each other.
A return to cannabis and a return of symptoms are different events. They have different warning signs. Either one can start the other. People who have co-occurring disorders often have symptoms that are more persistent, severe, and resistant to treatment [3]. So the aftercare plan needs to be longer and more specific than a single-condition plan.
It has to name four things. The prescriber, with the next appointment booked, because medication management means tailoring the type and dose to the person, and antipsychotic medications have risks and benefits to weigh with a clinician [2]. A therapist who knows about the cannabis use and the psychiatric history. A family member or friend who has been told the early warning signs in plain words: suspiciousness, paranoid ideas, uneasiness with others, withdrawing socially and spending much more time alone [2]. And an agreed rule for what happens if those signs appear.
People experience better outcomes from coordinated specialty care if they begin treatment as soon as possible after psychotic symptoms emerge [2]. Our page on how to get into rehab covers what the first call involves.
Frequently Asked Questions
Does cannabis cause psychosis? The evidence does not support putting it that plainly. What NIDA reports is that some evidence has linked cannabis use to earlier onset of psychosis in people with genetic risk factors for psychotic disorders, including schizophrenia, as well as worse symptoms in people who already have these conditions. Both qualifiers belong in the first half, and the second half applies to anyone already living with one of these conditions. NIDA also reports that cannabis intoxication can induce a temporary psychotic episode in some people, especially at high doses. Separately, NIMH lists the misuse of alcohol or drugs among the possible causes of psychosis alongside sleep deprivation and certain prescription medications.
How do clinicians tell drug-induced psychosis from a psychotic disorder? Largely by watching what happens over time. Symptoms may overlap, which is why accurate diagnosis is key in co-occurring presentations. Symptoms that clear as the substance clears point one way; symptoms that persist after it has point the other. A firm answer usually takes weeks, and treatment does not wait for it, because reducing the duration of untreated psychosis is critical.
Will my antipsychotic medication be stopped in treatment? Not as a matter of policy, and not by anyone who has not examined you. Treatment of psychosis usually includes antipsychotic medication, so the normal outcome is that it continues as part of one combined plan. Bring the medication and the prescriber’s details to the assessment. Stopping it is a decision to make with the prescriber rather than alone.
Is cannabis use disorder actually common? More common than most people assume. Studies have estimated that 22% to 30% of people who use cannabis have the disorder. Regular, heavy use in adolescence is also associated with negative effects on working memory, processing speed, verbal memory and academic functioning. Neither figure tells any individual what is true of them, which is what an assessment is for.
Does insurance cover treatment when psychosis is involved? Usually in some form, though the level of care drives the detail. Marketplace plans must include mental health and substance use services among the essential health benefits and cannot apply yearly or lifetime dollar limits to that care. Ask whether psychiatric care and substance use care are authorized separately before admission. We claim no network status with any carrier, so verify against your own member ID.
Sources
- National Institute on Drug Abuse. Cannabis (Marijuana). National Institutes of Health. https://nida.nih.gov/research-topics/cannabis-marijuana
- National Institute of Mental Health. Understanding Psychosis. National Institutes of Health. https://www.nimh.nih.gov/health/publications/understanding-psychosis
- National Institute on Drug Abuse. Co-Occurring Disorders and Health Conditions. National Institutes of Health. https://nida.nih.gov/research-topics/co-occurring-disorders-health-conditions
- National Institute of Mental Health. Finding Help for Co-Occurring Substance Use and Mental Disorders. National Institutes of Health. https://www.nimh.nih.gov/health/topics/substance-use-and-mental-health
- HealthCare.gov. Mental health and substance abuse health coverage options. US Centers for Medicare and Medicaid Services. https://www.healthcare.gov/coverage/mental-health-substance-abuse-coverage/
This page is for general information and is not medical advice. Only a licensed clinician who knows your history can tell you what is right for you. If you or someone you know is in immediate danger, call 911. For free, confidential support 24/7, call or text 988.
Author
Chief Medical Officer,
The Recovery Village
