Cannabis abuse

Cannabis use disorder (CUD), also known as cannabis addiction or marijuana addiction, is defined in the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and ICD-10 as the continued use of cannabis despite clinically significant impairment. Cannabis use and abuse has symptoms that affect behavior, physical, cognitive, and psychosocial aspects of a person's life. Symptoms include agitation, bloodshot eyes, challenges in problem solving, and paranoia. Cannabis use is associated with comorbid mental health problems, such as mood and anxiety disorders, and discontinuing cannabis use is difficult for some users. Psychiatric comorbidities are often present in dependent cannabis users including a range of personality disorders. The use of cannabis at a young age such as the teenage years, can have serious impacts on depression and anxiety in youth and later in life. There is evidence that cannabis use during adolescence, at a time when the brain is still developing, may have deleterious effects on neural development and later cognitive functioning. The brain is not completely developed until a person reaches the age range of 22-27. Excessive use of marijuana can cause harm to this development. Based on annual survey data, 7% of high school seniors that smoke daily function at a lower rate in school than students that do not. The sedating and anxiolytic properties of tetrahydrocannabinol (THC) in some users might make the use of cannabis an attempt to self-medicate personality or psychiatric disorders. Prolonged cannabis use produces both pharmacokinetic changes (how the drug is absorbed, distributed, metabolized, and excreted) and pharmacodynamic changes (how the drug interacts with target cells) to the body. These changes require the user to consume higher doses of the drug to achieve a common desirable effect (known as a higher tolerance), reinforcing the body's metabolic systems for eliminating the drug more efficiently and further down-regulating cannabinoid receptors in the brain. Cannabis users have shown decreased reactivity to dopamine, suggesting a possible link to a dampening of the reward system of the brain and an increase in negative emotion and addiction severity. Cannabis users can develop tolerance to the effects of THC. Tolerance to the behavioral and psychological effects of THC has been demonstrated in adolescent humans and animals. The mechanisms that create this tolerance to THC are thought to involve changes in cannabinoid receptor function. According to the National Cannabis Prevention and Information Centre in Australia, a sign of cannabis dependence is that an individual spends noticeably more time than the average recreational user recovering from the use of or obtaining cannabis. For some, using cannabis becomes a substantial and disruptive part of an individual's life and he or she may exhibit difficulties in meeting personal obligations or participating in important life activities, preferring to use cannabis instead. People who are cannabis dependent have the inability to stop or decrease using cannabis on their own. One study has shown that between 2001-2002 and 2012-2013, the use of marijuana in the US doubled.