Many medications can affect your thinking process, that is why doctors and nurses advise for you not to make any important decisions following anesthesia after surgery. A psychoactive drug or psychotropic substance is a chemical substance that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior. Medical Marijuana does contain THC which is psychoactive. Other psychoactive drugs include; caffeine, nicotine, alcohol, opioids, benzo's, anesthesia, and psychiatric medications. Even benadryl if taken in high doses can produce hallucinations. However, medical marijuana contains CBD which counter acts the psychoactive effects of THC. Gear towards ratios higher in CBD than THC to avoid any psychoactive stimulation.