SCIENCE JOURNAL 2018

In grey matter density; which contains neuronal cell bodies that control sensory perception and muscle control, and white matter density; which connects grey matter, have been reported in different locations in frontal and parietal lobes of the brain. In addition, decrease in hippocampus volume has been correlated with lifetime consumption. Research shows that the drug can cause memory deficiencies and less active hippocampus activity which is the area in the brain associated with memory. A study was conducted by (American College of Paediatricians. 2018) following 3385 patients who were between 18 and 30 in 1985 for 25 years. At the end of the study a cognitive function was assed including tests of verbal memory, processing speed and executive functioning. The results showed that for every 5 years of the past marijuana use, verbal memory decreased significantly, showing there is a clear relationship to marijuana and long-term memory deficiencies. According to (DrugAbuse.com. 2018.) marijuana can in fact lead to addiction stating that 25-50% of users whom take the drug regularly will become addicted at some point, leading to very serious long term mental health effects. Mental Health Effects There is ongoing growth of evidence that there is a link between marijuana and mental illnesses. Research suggests that people with serious mental illnesses are more likely to use cannabis or have used it for long periods of time. With researchers saying that regular use of the drug has appeared to double the risk of developing a psychotic episode and other long term illnesses (Royal College of Psychiatrists. 2018). One of the most common illnesses that can be affected by the drug is depression , a study done by the Royal

College of Psychiatrists following 1600 Australian children aged 14-15 for 7 years found that adolescents who used cannabis daily are five times more likely to develop depression than someone who does not. In contrast, schizophrenia is another common illness that can be stimulated through cannabis with regular cannabis users having double the risk of non-users. Referring graph 2, it is evident that the schizophrenia rate is significantly increased as the usage of the drug increased with the ratio of non users to users 1:6 meaning that for every non user with schizophrenia, there are 6 cannabis users with schizophrenia. Statistics also show that those who have used cannabis at some point in their life have a 40% increased risk of the illness then those whom have not (National Institute on Drug Abuse. 2018). Both examples suggesting that there is a clear relationship between cannabis and schizophrenia. Referring to Graph One “Mood and Anxiety Disorders Among Respondents with Marijuana Dependence (NESARC)” it is evident that the percentage of respondents that depended on marijuana is much higher than the percentage the general population. More specifically, 47% of marijuana dependent respondents had connections to depression and only 17% of the general population had connections with the illness. This suggests that the illness can be directly affected by the drug. The graph also shows that there was a 33% difference between marijuana users and non marijuana users over any anxiety disorder. The graph as a whole evidently proves that marijuana has a significant connection with mental illnesses with the statistics differentiating extremely in percentages between marijuana respondents and the general population.

SC J SI

29

Somerset College Journal of Scientific Issues

Year 10