The belief that almost all abusers of more powerfully addictive drugs have first experimented with alcohol, tobacco, or marijuana, is also known as _________ theory.

• A. Adjunct
• B. Designer
• C. Illicit
• D. Gateway

Answer: (D)

The idea being tested is that initial use of widely available, milder substances can set the stage for later use of stronger, more addictive drugs. This pattern is captured by the gateway theory. It describes how people who start with alcohol, tobacco, or marijuana may be more likely to progress to harder drugs, due to factors like changes in brain reward pathways, increasing tolerance, or social environments that normalize drug experimentation. It’s important to note that gateway theory doesn’t claim a direct, simple cause-and-effect chain; there are often shared risk factors that make someone more prone to multiple substances. The other terms don’t fit: adjunct would imply something that accompanies another substance, designer refers to synthetic variants of drugs, and illicit simply means illegal, not a progression pattern.