Employee Marijuana use is seen in the workplace in lower productivity, increased workplace accidents and injuries, increased absenteeism, and lower morale.
The short-term effects of marijuana use include problems with memory and learning, distorted perception, difficultly in thinking and problem-solving, and loss of coordination. The ability to concentrate and maintain attention are decreased during marijuana use, and impairment of hand-eye coordination is dose-related over a wide range of dosages.
Marijuana affects brain development. When people begin using marijuana as teenagers, the drug may reduce thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions.
Students who smoke marijuana tend to get lower grades and are more likely to drop out of high school than their peers who do not use. The effects of marijuana on attention, memory, and learning can last for days or weeks.
Frequent or long-term marijuana use is linked to school dropout and lower educational achievement.
Heavy and frequent alcohol use may interfere with a young person’s capacity to make prosocial choices. Frequent, heavy use of alcohol has been associated with low self-esteem, depression, conduct disorders, antisocial behavior, and anxiety in adolescents.
Brown, S.A., and Tapert, S.F. 2004. Health consequences of adolescent alcohol involvement. In Reducing marijuana use: A Collective Responsibility, edited by R.J. Bonnie and M.E. O’Connell. Washington, DC: The National Academies Press, pp. 383–401.
Marijuana use has been linked to a range of mental health problems in teens such as depression or anxiety. Psychosis has also been seen in teens at higher risk like those with a family history.
Regular use of marijuana has also been linked to depression, anxiety, and a loss of drive or motivation, which means a loss of interest even in previously enjoyable activities.
Marijuana affects a number of skills required for safe driving—alertness, concentration, coordination, and reaction time—so it’s not safe to drive high or to ride with someone who’s been smoking. Marijuana makes it hard to judge distances and react to signals and sounds on the road. High school seniors who smoke marijuana are two times more likely to receive a traffic ticket and 65% more likely to get into an accident than those who don’t smoke.
Marijuana use can lead to the development of problem use, known as a marijuana use disorder, which takes the form of substance use disorder in severe cases. Recent data suggest that 30 percent of those who use marijuana may have some degree of marijuana use disorder. People who begin using marijuana before the age of 18 are four to seven times more likely to develop a marijuana use disorder than adults.
Marijuana is addicting as it causes compulsive drug craving, seeking, and use, even in the face of negative health and social consequences. Additionally, animal studies suggest marijuana causes physical dependence. Withdrawal symptoms are often seen in chronic marijuana users if they stop using it abruptly. Symptoms include restlessness, irritability, mild agitation, hyperactivity, insomnia, nausea, cramping, decreased appetite, sweating, and increased dreaming.