What is the chemistry?
Marijuana comes from cannabis plants, native to Central and South Asia. The plant’s leaves, flowers, stem, and seeds are all rich in THC (tetrahydrocannabinol), the chemical that creates the drug’s psychoactive effects.
THC affects brain receptors associated with memory, pleasure, coordination, and judgment. When these receptors are stimulated, the classic marijuana “high” takes effect, typically accompanied by distorted sensual perceptions, changes in mood, and impairment of mental functioning.
What is the history of the drug?
Recreational and religious cannabis use goes back literally thousands of years. Charred seeds have been found in a ritual brazier in Romania, at a burial site dated to the third millennium BC. At about the same time (roughly 2700 BC), the Chinese medical encyclopedia Pen Ts’ao, compiled by emperor Shen-Nung, referred to ma (the Chinese name for cannabis) as a medicine that uniquely balanced yin and yang forces. The drug was recommended for treating menstrual cramps, gout, rheumatism, malaria, and (ironically enough, given that modern medical science considers marijuana use a potential source of permanent memory damage) absentmindedness. In the early second century, Chinese doctor Hua T’o used cannabis as a surgical anesthetic.
The drug got considerably less respect in mid-twentieth-century America, where it became associated with teenage rebellion and getting high for the fun of it. Use was illegal throughout the United States until 1996, when California approved marijuana for use in medicine. Currently, twenty-nine states and the District of Columbia allow some level of legal use; as of late 2017, however, the drug remains a Schedule I substance (no recognized medical use) under federal law. The FDA does recognize two cannabis-derived nausea medications, dronabinol and nabilone.
What are the side effects?
Marijuana affects virtually every part of the body and nervous system. Common physical reactions include red eyes, dilated pupils, dry mouth, increased appetite, dizziness, a distorted sense of time and place, hallucinations, accelerated heart rate (sometimes to double speed), and slowed reaction times.
Initial effects of a single dose last only a few hours, but regular users may also develop chronic coughing or respiratory infections from frequent smoking. If they continue using for the long term, other effects that may eventually surface include heart and blood pressure problems, lung damage, impaired memory, panic attacks, flashbacks, sexual dysfunction, or cannabinoid hyperemesis syndrome (chronic and severe vomiting).
How was it intended to be used?
Traditionally, marijuana’s mind-altering effect made it a popular tool for inducing mystic experiences. As noted above, it was also used in classic Chinese medicine.
Today, Western medicine is exploring new options for medical use of marijuana, particularly in relieving chronic pain. Other medical conditions for which a doctor might prescribe marijuana include multiple sclerosis, digestive difficulties, seizure disorders, glaucoma, and Crohn’s disease.
How is it used illicitly?
Outside of medically monitored use, marijuana is most commonly smoked in hand-rolled cigarettes (joints), pipes, or vaporizers. Some smokers opt for “blunts” (cigars in which some or all of the tobacco has been replaced with marijuana). Other users take it in tea or mixed with food—a potential risk if someone used to the quicker effects of inhalation eats more with the idea of speeding things up.
A more dangerous approach is “dabbing,” which involves smoking marijuana resins heated with butane, and delivers a much stronger THC dose than the standard marijuana derived from solid parts of the plant.
Marijuana remains the most commonly used illicit drug in the United States. It is smoked recreationally to induce euphoric or spiritual experiences, and as self-medication by chronic-pain sufferers who can’t obtain legal medical marijuana.
What are the signs of illicit use?
Symptoms of frequent use include: bloodshot eyes, lethargy, fast heart rate, increased appetite, strange odors on clothes or breath, mental confusion, and hyperactivity.
Symptoms of dependence (marijuana use disorder) include: loss of interest in usual activities, increased secretiveness, mood and sleep difficulties, and irritability.
Symptoms of overdose (frequently from “dabbing”—but as with many illicit drugs, the more common form of marijuana has become stronger and thus riskier than it was a generation or two ago) include: severe agitation, vivid hallucinations, psychosis, hammering heart, pale complexion, gasping for breath, and severe shakiness. While marijuana overdoses are rarely fatal in themselves, they may trigger suicidal behavior or cardiac arrest. Call for emergency medical help.