Question

Cigarettes and marijuana are often considered to be “gateway drugs.” Consider everything you have read about changes in brain chemistry, analyze this statement from a biological perspective. Do you agree with this perspective? Why or why not?

Answer 1

Adverse Effects of Short-Term Use and Long-Term or Heavy Use of Marijuana.

Effects of short-term use

Impaired short-term memory, making it difficult to learn and to retain information

Impaired motor coordination, interfering with driving skills and increasing the risk of injuries

Altered judgment, increasing the risk of sexual behaviors that facilitate the transmission of sexually transmitted diseases

In high doses, paranoia and psychosis

Effects of long-term or heavy use

Addiction (in about 9% of users overall, 17% of those who begin use in adolescence, and 25 to 50% of those who are daily users)*

Altered brain development*

Poor educational outcome, with increased likelihood of dropping out of school*

Cognitive impairment, with lower IQ among those who were frequent users during adolescence*

Diminished life satisfaction and achievement (determined on the basis of subjective and objective measures as compared with such ratings in the general population)*

Symptoms of chronic bronchitis

ADVERSE EFFECTS

• RISK OF ADDICTION
• EFFECT ON BRAIN DEVELOPMENT
• POSSIBLE ROLE AS GATEWAY DRUG
• RELATION TO MENTAL ILLNESS
• EFFECT ON SCHOOL PERFORMANCE AND LIFETIME ACHIEVEMENT
• RISK OF MOTOR-VEHICLE ACCIDENTS
• RISK OF CANCER AND OTHER EFFECTS ON HEALTH
• LIMITATIONS OF THE EVIDENCE AND GAPS IN KNOWLEDGE

Marijuana use has been associated with substantial adverse effects, some of which have been determined with a high level of confidence. Marijuana, like other drugs of abuse, can result in addiction. During intoxication, marijuana can interfere with cognitive function (e.g., memory and perception of time) and motor function (e.g., coordination), and these effects can have detrimental consequences (e.g., motor-vehicle accidents). Repeated marijuana use during adolescence may result in long-lasting changes in brain function that can jeopardize educational, professional, and social achievements. However, the effects of a drug (legal or illegal) on individual health are determined not only by its pharmacologic properties but also by its availability and social acceptability. In this respect, legal drugs (alcohol and tobacco) offer a sobering perspective, accounting for the greatest burden of disease associated with drugs77 not because they are more dangerous than illegal drugs but because their legal status allows for more widespread exposure. As policy shifts toward legalization of marijuana, it is reasonable and probably prudent to hypothesize that its use will increase and that, by extension, so will the number of persons for whom there will be negative health consequences.

Clinical Conditions with Symptoms That May Be Relieved by Treatment with Marijuana or Other Cannabinoids.

• Glaucoma

• Nausea

• AIDS-associated anorexia and wasting syndrome

• Chronic pain

• Inflammation

• Multiple sclerosis

• Epilepsy