Cannabis and Schizophrenia
Major Constituents of Cannabis The two major substances found in cannabis include tetrahydrocannabinol (THC) and cannibidiol (CBD) THC is the major psychoactive substance found in cannabis THC acts as an agonist while CBD acts as an antagonist by having the same effect as neuroleptics
THC effectively acts as a dopamine agonist, thus blocking the reuptake of dopamine and L-DOPA (which stimulates the synthesis of dopamine) Produces an overactivity of dopaminergic synapses in the nucleus accumbens Dopaminergic neurons are involved in reinforcement.
Areas of The Brain Most Affected by THC Basal Ganglia, and the Cerebellum (Motor Tasks) Hippocampus (Short-Term Memory) Cannabinoids inhibit the transmission of neural signals
Correlation Between THC and Schizophrenia A relatively small proportion of cannabis users develop psychosis Explained by the amount and duration of the consumption of cannabis, its strength, and also the age at which individuals are exposed to cannabis Genetic factors – COMT (catechol-O-methyl transferase)
Those Most at Risk of Developing Schizophrenia Users under the age of 21, as the human brain has not fully matured Users under the age of 15 are 4. 5 times more likely to develop psychosis by the age of 26 An increase in the concentration of dopamine in a developing brain increases the likelihood of developing schizophrenia in early adulthood
Physical Harm vs. Dependency
CBD Cannabidiol (CBD) represents up to 40% of cannabis extracts Found to reduce schizophrenic symptoms by blocking dopamine receptors Prevents the storage of monoamines in synaptic vesicles Cannabidiol has no affinity for CB 1 receptors http: //www. youtube. com/watch? v=g. Afs_No 8 l. E 8