Marijuana is the most commonly used illicit drug in the United States. When smoked, it begins to effect users almost immediately and can last for one to three hours. When it is eaten in food, such as baked in brownies and cookies, the effects take longer to begin, but usually last longer.
The active ingredient in marijuana, delta-9 tetrahydrocannabinol or THC, acts on cannabinoid receptors on nerve cells and influences the activity of those cells. Some brain areas have many cannabinoid receptors, but other areas of the brain have few or none at all. Many cannabinoid receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement. |
