One of the most crucial time periods of the development of the human brain is adolescence. The number of new neural pathways forming through neurogenesis at this time is very high. Aside from this, adolescence is also a time where individuals want to expand their horizons, and experiment. Some rebel and try new things – such as marijuana. The number of individuals who have tried marijuana as teens is high. It is said that 43% of US students have tried marijuana by graduation. Although these individuals may think it is harmless, evidence is stating that the use of cannabis at such a crucial time of development of one’s brain may have long term effects. In this study, Ashtari et al. (2011), examine the effects heavy cannabis usage has on the main brain areas affected by neurogenesis such as the hippocampus and the amygdala, as well as other areas with strong cannabinoid receptors.
Studies have shown that the hippocampus is related to drug seeking and administering behaviours. The hippocampus is also the primary area associated with memory. Because THC, which is a cannabinoid found in marijuana, is toxic to this area and other high cannabinoid receptor areas such as the frontal lobe, and the basal ganglia, the excessive use of cannabis may be harmful to the structure and function of these areas. An emphasis of its affects is placed on the hippocampus though due to its active development in adolescence which is what this study is observing.
The main question being raised in this study was what kind of effects heavy cannabis use had on the brain structures and functions, more specifically the hippocampus of teenagers because it was of interest how neurogenesis would be affected. It was predicted that there would be a significant difference between the cannabis users and the controls
Fourteen cannabis dependent participants were chosen from a treatment center, averaging in age at 19.3 years. The criteria these participants needed to meet was extensive and included factors such as, an average of 5.8 joints a day, they had to be diagnosed solely of an dependence of marijuana, they could not have any psychiatric disorder and it was crucial that they be marijuana free for at least 30 days prior to the MRI. The control group consisted of fourteen participants averaging in age at 18.5. These participants were chosen if they had no prior addiction to drugs, or use of drugs more than five times in their lifetime. They also could not have any mental disorders. Participants were chosen from a mirroring socioeconomic and demographic area as the cannabis users. All participants in the study were male.
All participants were interviewed by a psychologist who was being supervised by a child-adolescent psychiatrist, and the interview followed the K-SADS (Schedule for Affective Disorders and Schizophrenia for School Aged Children) in order to obtain a consistent diagnosis procedure for all participants. All participants underwent an MRI (Magnetic Resonance imaging),...