Definition and Epidemiology
Cannabis use disorder (CUD) is defined as chronic (> 12 months) maladaptive use of cannabis.
- Heightened sensitivity to stimuli
- Derealization and depersonalization with higher dosage
- Motor skills are impaired for up to 8–12 hours after ingestion.
- Delirium and cannabis-induced psychotic disorders may also occur.
- Development of a substance-specific syndrome due to the cessation (or reduction) of substance use
- Very mild for cannabis and other inhalants/hallucinogen-type drugs
- The need to increase the dose of the substance to achieve desired effect (diminished effect if using the same amount of the substance)
- Evidence for physiological dependence is not strong for cannabis.
- Cannabis is the most widely used illicit substance.
- Used by an estimated 192 million people worldwide
- About 13 million individuals worldwide suffer from moderate-to-severe cannabis use disorder.
- Prevalence of CUD declines with increase in age.
- Men are more than twice as likely to have CUD as women.
- Cannabis is consumed from both naturally occuring and agriculture-selected strains (which have increased potency).
- Synthetic formulations available (e.g., “spice,” “K2”)
- Common ways of consumption:
- Smoking (most widespread)
- Baked into cookies or other sweets
- THC (tetrahydrocannabinol):
- The main active and most potent psychoactive component in cannabis
- 50% of THC enters the bloodstream via the alveoli in the lungs rapidly after inhalation.
- THC binds to cannabinoid receptors in the brain’s reward system → results in feelings of euphoria
- Synthetic cannabinoids have active compounds that are more potent than THC.
- Cannabinoid receptors are inhibitory G proteins → inhibit adenylate cyclase → decreases cAMP
- Cannabinoids are lipophilic → can remain in the body in detectable levels for days to weeks
Medical uses of cannabis
- Treatment of nausea and vomiting, appetite stimulation:
- Multiple sclerosis
- Chronic pain patients
- Decreasing intraocular pressure in glaucoma
- Childhood epilepsy and refractory seizures
Clinical Presentation and Diagnosis
To make the diagnosis of cannabis intoxication or withdrawal, a detailed history of cannabis use should be obtained. Urine drug screen aids in confirming the diagnosis. Signs and symptoms are listed below.
- No deaths have ever been documented from cannabis intoxication alone.
- General: euphoria or feeling relaxed, inappropriate laughter
- CNS: psychomotor retardation, impairment in motor function
- Ophthalmologic: conjunctival injection or “reddening” of the conjunctives
- GI: increased appetite, dry mouth
- Urine drug screen:
- Detects the major inactive metabolite 11-Nor-9-carboxy THC
- Single use can cause detectable levels for up to 3 days.
- Chronic use can cause detectable levels for up to 30 days.
- General: mood changes, slight increase in irritability
- CNS: insomnia
- GI: nausea, decreased appetite
Management and Complications
Management of cannabis intoxication and withdrawal
- Supportive, psychosocial interventions (e.g., contingency management, groups, etc.).
- Symptomatic treatment
- Antipsychotics may be used for severe intoxication.
Management of cannabis use disorder
- Psychotherapy: cognitive behavioral therapy (CBT) or motivational enhancement
- No strong evidence for any medications
- If psychotherapy alone is not effective, adding N-acetylcysteine (if adolescent/young adult) or gabapentin (adults) may be helpful.
Complications of cannabis use disorder
- Cannabis-induced psychotic disorder:
- Psychotic disorder in the setting of cannabis use
- More commonly presents with transient paranoid delusions
- Chronic cannabis use has been linked with the development of schizophrenia later in life.
- Amotivational syndrome:
- Associated with long-term severe cannabis use
- Can be confounded with underlying mood disorder
- Adolescent use of cannabis is linked with use of other substances (gateway drug).
- Schizophrenia: a chronic mental health disorder that is characterized by both positive (delusions, hallucinations, disorganized speech or behavior) and negative symptoms (flat affect, avolition, anhedonia, poor attention, and alogia). The disorder is associated with a decline in functioning lasting over 6 months. The use of cannabis may result in psychosis and symptoms similar to schizophrenia in the acute phase. Management of schizophrenia is with antipsychotics.
- Cocaine use disorder: cocaine is an indirect sympathomimetic that blocks the reuptake of dopamine, epinephrine, and norepinephrine from the synaptic cleft. This process causes a stimulating effect (euphoria, increased energy, irritability, psychosis, decreased appetite, weight loss, and hypersomnia) similar to but more pronounced than cannabis. Withdrawal symptoms include severe depression and fatigue. Management is very similar to cannabis in that there is no direct medication that can be used for cocaine use disorder.
- Inhalant intoxication: the abuse of inhalant substances such as glue, paint, or lighter fluid. In order to reach euphoric effects, patients administer inhalers through the mouth (commonly known as “huffing”) or sniff substances through the nose. The effect lasts only for several minutes. Signs of acute intoxication range from transient euphoria up to a loss of consciousness. Inhalants result in central nervous inhibition and cardiac arrhythmia. Treatment is supportive, and sedative drugs should be avoided as they tend to worsen intoxication.
- Ganti, Latha. (2005). First aid for the psychiatry clerkship: a student-to-student guide. New York :McGraw-Hill, Medical Pub. Div. Chapter 7, Substance related and addictive disorders, pages 80, 92.
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