What is the main psychoactive ingredient in marijuana?

The main psychoactive ingredient in marijuana is THC, or tetrahydrocannabinol. THC is responsible for the "high" sensation that users experience when consuming marijuana. It interacts primarily with cannabinoid receptors in the brain, influencing various mental processes, including mood, memory, and perception. This psychoactive effect is a defining characteristic that distinguishes THC from other compounds found in marijuana.

While CBD (cannabidiol) is another well-known compound in marijuana with various therapeutic effects, it does not produce the same psychoactive effects as THC. Other compounds like CBDV (cannabidivarin) and CBN (cannabinol) are present in marijuana but are not the principal constituents responsible for its psychoactive properties. Thus, THC is correctly identified as the main psychoactive ingredient.