Marijuana----- Marijuana overactivates parts of the brain that contain the highest number of these receptors. This causes the "high" that people feel. Other effects include: altered senses (for example, seeing brighter colors) altered sense of time changes in mood impaired body movement difficulty with thinking and problem-solving impaired memory hallucinations (when taken in high doses) delusions (when taken in high doses) psychosis (when taken in high doses) Seek medical help contact your doctor .. Dr Rohan jahagirdar MD Psychiatry