What is Cannabis Use Disorder?
Cannabis use disorder (CUD) is defined as the problematic use of marijuana and other related intoxicants. People with CUD experience distress or impairment of daily functioning associated with their cannabis use. People with the disorder also continue to use the drug despite its negative impact on their lives and health.
There is some controversy about the prevalence of CUD. One study has estimated that about 1.5% of all adults meet the diagnostic criteria for the disorder. However, the same study notes that the rate of CUD in the United States has remained constant during a period in which cannabis use increased dramatically. CUD rates among adult cannabis users decreased by about one-third during the same period. However, another study reported increases in CUD prevalence, especially among adolescents, during a similar period.
Symptoms of CUD
Symptoms of CUD can include:
- Developing a tolerance for the drug that causes you to need more of it to achieve the same effect
- Developing dependence on the drug so that you need to use it to feel well
- Experiencing problems with memory, attention, or thought processes
General effects of cannabis use can include:
- Increased appetite
- Decreased pain sensation
- Decreased anxiety
- Relief from nausea
- Muscle relaxation
- Dry mouth
- Bloodshot eyes
- Rapid heart rate
- Low blood pressure
- Slowed digestion
Symptoms of withdrawal that come after the discontinuation of marijuana use can include:
- Nervousness or anxiety
- Anger or aggression
- Sleep disruptions
- Decreased appetite
What Causes Cannabis Use Disorder?
About 90% of people who use marijuana do not develop CUD or problematic usage patterns. Scientists don’t know what causes some people to develop the disorder. However, some factors seem to increase the risk of CUD. These risk factors include:
- Age. People who begin using marijuana in adolescence are at increased risk of developing CUD.
- Family history. People who have close relatives who have suffered from drug addiction are more likely to develop an addiction themselves.
- Abuse of other substances. Problematic marijuana use often occurs in conjunction with the use of nicotine, alcohol, or other drugs.
Is Cannabis Use Disorder Hereditary?
Addiction to drugs can have many causes, and many are situational. However, studies have indicated that some people are more likely to abuse or become addicted to certain drugs. The increased risk seems to be determined by genetics and is likely inherited within families.
Scientists do not fully understand inherited addiction risk. It is likely that many different genes are involved and that the inherited risk has a complex cause.
How Is Cannabis Use Disorder Detected?
Because many people use marijuana without noticeable adverse effects, it can be challenging to identify when someone has a problem with the drug.
Potential warning signs of problematic marijuana use include:
- Using marijuana more often or in greater quantities than in the past
- Having problems at work or school associated with marijuana use
- Continuing to use marijuana despite its adverse effects
- Spending more money on marijuana
How Is Cannabis Use Disorder Diagnosed?
The Diagnostic and Statistical Manual (DSM), the guide used by mental health practitioners to diagnose disorders, includes diagnostic criteria for cannabis use disorder that closely follows the criteria for other substance use disorders.
To be diagnosed with CUD, a marijuana user must experience at least two of the following symptoms:
- Strong desire to take the drug
- Tolerance (a need for an increased amount of marijuana to maintain its effects)
- Withdrawal symptoms
- Use of more of the drug than the user initially intended to use
- Desire to quit, or unsuccessful attempts to stop using the drug
- Spending significant time, effort, and money to acquire, use or recover from the drug
- Drug use interferes with important activities or obligations
- Drug use continues even when the user knows it causes harm
- Drug use in dangerous locations or situations
How Is Cannabis Use Disorder Treated?
Behavioral or group-based psychotherapies are also commonly used to treat CUD.
- Contingency Management Therapy (CM). This type of therapy, also called motivational therapy, rewards patients for successfully abstaining from drug use. The rewards, monetary or otherwise, are given to patients when they successfully reach milestones of abstinence.
- Cognitive Behavioral Therapy (CBT). This type of psychotherapy helps drug users to recognize the triggers that prompt their drug use. The therapy also focuses on developing strategies and techniques for dealing with those triggers when they occur. CBT is effective at preventing relapses once the patient has begun to abstain from drug use.
How Does Cannabis Use Disorder Progress?
Most people do not experience severe, long-term consequences from their marijuana. However, some people might be at risk of health problems and quality-of-life issues. Possible complications include:
- Problems at school or work
- Relationship problems
- Attention deficits
- Memory and cognitive impairments
- Worsening of psychotic symptoms in people with a co-existing psychotic disorder
- Delusions or hallucinations
- Chronic bronchitis
- Fertility problems
How Is Cannabis Use Disorder Prevented?
Some people who regularly use marijuana will develop a dependence on the drug, and there is no known way to prevent the condition. Limiting use and seeking treatment when you see signs of a problem are the best strategy for lessening the impact of CUD.
Cannabis Use Disorder Caregiver Tips
Some people with cannabis use disorder also suffer from other brain and mental health-related issues, a condition called co-morbidity. Here are a few of the disorders sometimes associated with CUD:
Cannabis Use Disorder Brain Science
Researchers have long known that some people are more prone to substance abuse and addiction than others. Some of the increased risk can be attributed to an inherited trait that makes certain people respond differently to drugs. Their different responses may make these people more likely to develop a dependence on drugs once they begin using them.
One recent project has looked at a different explanation for why some people are more prone to substance abuse problems. Focusing on the notion that substance abuse and addiction are problems that stem from decision-making errors, a team of scientists at the University of Southern California has suggested that the prefrontal cortex–the part of the brain responsible for impulse control, goal-setting, and prediction of consequences of actions–may be to blame.
The scientists believe that an underdeveloped prefrontal cortex may make an individual more likely to make the choices that lead to substance abuse and addiction–or even to using drugs in the first place. Genetic factors may cause the prefrontal cortex’s underdevelopment, or it may result from a head injury or other environmental circumstances. The team hopes that further research can narrow the search for the root causes of addiction.
Cannabis Use Disorder Research
Title: Influence of Tobacco Use on Cannabis Use
Principal Investigator: Margaret Haney, PhD
New York State Psychiatric Institute
New York, NY
Cannabis smokers who also smoke tobacco cigarettes have markedly higher rates of cannabis relapse relative to those who do not use tobacco. There is a clear need to develop and evaluate interventions for dual tobacco and cannabis users. The investigators of this study have previously shown that the co-use of tobacco cigarettes contributes to the maintenance of daily cannabis use and that age of cigarette onset is a critical predictor of treatment outcome. Short-term tobacco cessation may suffice in altering cannabis relapse rates in later-onset cigarette smokers, while a longer period of tobacco cessation may be needed for earlier-onset smokers. In the current study, a human laboratory model will be utilized to determine whether cannabis relapse varies as a function of tobacco cessation duration and age of tobacco use onset.
Title: Impact of Reduced Cannabis Use on Functional Outcomes (R33 Phase) (FOCUS)
Contact: Angela C. Kirby, MS
Duke University Medical Center
Nearly 20 million Americans report the use of cannabis in the past month, and heavy cannabis use has increased by nearly 60% in the US since 2007. Heavy cannabis use is associated with lower educational attainment, reduced physical activity, increased rates of addiction and unemployment, and neuropsychological deficits. Studies suggest that cannabis use is also associated with increased mental health symptoms, drugged driving, and traffic accidents. While there is evidence that sustained abstinence can lead to improvements in the functional outcomes of former users, the degree to which reductions alone (i.e., not sustained abstinence) in cannabis use might be associated with positive changes in functional outcomes is unknown. This is a critical gap in the literature, as many interventions for cannabis and other drugs are associated with decreases in frequency and quantity of use but fail to affect overall abstinence rates. The objective of the present research is to use ecological momentary assessment (EMA), a real-time, naturalistic data collection method, to prospectively study the impact of reduced cannabis use on functional outcomes in heavy cannabis users. Contingency management (CM) will be used to promote reductions in the frequency and quantity of cannabis use. CM is an intensive behavioral therapy that is highly effective at producing short-term reductions in illicit drug use. We have recently developed a novel approach that leverages mobile technology and recent developments in cannabis testing. We have pilot-tested this approach with heavy cannabis users and found it is an acceptable and feasible method. The present research will use this technology in conjunction with EMA methods to study the impact of reduced cannabis use on key functional outcomes. Our central hypothesis is that reductions in frequency and quantity of cannabis use will lead to positive changes in cannabis users’ mental health, self-efficacy, physical activity, working memory, health-related quality of life, and driving behavior. The rationale for this research is that it will provide the first and only real-time data concerning the potential impact of reductions in cannabis use on functional outcomes. As such, the findings from the present research will directly inform ongoing efforts to include reductions in illicit drug use as a valid, clinically-meaningful outcome measure in clinical trials of pharmacotherapies for the treatment of substance use disorders.
Title: Cannabis and Aging
Contact: Thorsten Rudroff, PhD
University of Iowa
Iowa City, IA
The prevalence of cannabis use has increased significantly in recent years among US adults aged 50 years and older. With increased availability and use of cannabis by older adults, a rigorous evaluation of the benefits and risks of cannabis use in these individuals is necessary. Aging is characterized by physiological and social changes that make older adults vulnerable to chronic disease and geriatric conditions, including cognitive impairment and falls. Unintentional falls are a common event for older adults and a significant cause of morbidity and mortality linked with a decline in functional status and disability. Moreover, falls and cognitive impairment are a “well-known couple”; older adults with moderate to severe cognitive impairment have a higher risk of falls, with an annual incidence of around 60-80%, twice the rate of cognitively normal older adults. Impaired cognitive function is an effect of cannabis use, and there is increasing evidence that those effects may persist later in life. Therefore, the physiological effects of chronic cannabis use may further increase falls in older adults via alterations in gait and cognition. Studies have shown reduced neural activity in the frontal brain networks and associations with increased fear of falling in older adults. It is also known that in regular cannabis users, the effects of cannabis may have an impact on cognitive-motor skills and brain mechanisms that modulate coordinated movement. This application aims to investigate the neural correlates of fall risk and cognitive and motor function in individuals who initiate drug use after the age of 50. We will use FDG-PET to determine brain activity. Fall risk and cognitive/motor function will be assessed with the measures from the NIH Toolbox and a fall risk model. Our central hypothesis is that older chronic cannabis users are at a higher fall risk than older non-users, which is associated with reduced cerebral FDG uptake. These results are expected to provide critical and timely data to the public and health professionals regarding the effects of self-directed cannabis use on increased fall risk and if clinicians need to assess cannabis use when determining fall risk and deciding prevention strategies.