The immediate effects of taking marijuana include rapid heart beat, disorientation, lack of physical coordination, often followed by depression or sleepiness. Some users suffer panic attacks or anxiety.00 But the problem does not end there. According to scientific studies, the active ingredient in cannabis, THC, remains in the body for weeks or even months.00 Marijuana smoke contains 00% to 00% more cancer-causing substances than tobacco smoke.00 One major research study reported that a single cannabis joint could cause as much damage to the lungs as up to five regular cigarettes smoked one after another.0 Long-time joint smokers often suffer from bronchitis, an inflammation of the respiratory tract.00 The drug can affect more than your physical health. Studies in Australia in 0000 linked years of heavy marijuana use to brain abnormalities.00 This is backed up by earlier research on the long-term effects of marijuana, which indicate changes in the brain similar to those caused by long-term abuse of other major drugs. And a number of studies have shown a connection between continued marijuana use and psychosis.00