@deni – Some weeks ago I read an article in a German print magazine citing studies done with high school and college students. There are negative effects with both alcohol and cannabis usage. I tried to find some information available online and in English. Maybe this is a good start
http://www.livestrong.com/article/24680-effects-marijuana-use-college-students/
“The immediate effects of marijuana use in college students are almost always apparent. Upon inhalation of the THC chemicals in marijuana, students experience increased heart rate, dry mouth and blood shot eyes. They lose coordination and have difficulty speaking and listening, interrupting class work and social relationships. The altered states of being high make it more difficult to acquire and retain new information and comprehend new ideas and information. Marijuana is psychologically addicting, which can lead to the need for treatment and loss of time that could be spent towards a degree.”
http://alcoholism.about.com/od/pot/a/social.htm
“A vast amount of scientific research has shown that heavy marijuana use negatively affects smokers’ learning abilities and social skills, causing problems in their daily lives and compounding their existing problems. The National Institute on Drug Abuse has surveyed and compiled 11 scientific research studies that have demonstrated that heavy marijuana use, defined as smoking marijuana 27 days in the past 30 days, has a significant impact on users’ ability to learn, remember what they learned and function in society.”
http://news.bbc.co.uk/2/hi/6606931.stm
“They then carried out brain scans, and a battery of tests, and found that those who took THC showed reduced activity in an area of the brain called the inferior frontal cortex, which keeps inappropriate thoughts and behaviour, such as swearing and paranoia in check.”
“If something has an active effect in inducing the symptoms of psychosis after one dose, then it would not be at all surprising if repeated use induced the chronic condition. Professor Murray also warned that the high potency cannabis now widely available was likely to pose a much bigger risk to health than the significantly weaker formulations of previous years. It is similar to comparing the effect of drinking a glass of wine at the weekend with drinking a bottle of vodka every day. Marjorie Wallace, of the mental health charity Sane, called the research a significant contribution to the understanding of the dangers of cannabis.”
Don’t get me wrong. I think both alcohol and cannabis should be legal. But people need to know what they are doing. Cannabis is not peppermint tea.