When using any substance there is always going to be an effect on a number of areas of the body, this is especially true when it comes to the brain. The effects the brain can encounter from using a substance can effect things like thought patterns, memory and both physical and mental functions, resulting both short and long term effects.
When consuming alcohol various areas of the brain are affected, these areas include GABA, glutamate and dopamine. When our glutamate receptors and GABA center receptors are affected by alcohol the physical effects associated with drinking present themselves. Short term effects such as slurred speech and slow movement and reflexes are what provide the drunk feeling we encounter when consuming alcohol. When alcohol interacts with our dopamine receptors our brain produces more dopamine which causes us to be happier and feel more pleasurable, this is the happy relaxing feeling we get when consuming alcohol. These positive pleasurable feelings are known as part of the biphasic effect which has two phases, this phase being the first. The second phase is when things like motor functions start to become difficult, this is when people start to feel overly intoxicated due to the brain being overloaded, which can result in the body rejecting alcohol with nausea and vomiting. On a short-term basis this can lead to memory loss, poor decision making and blacking out. Long term effects can have a longer lasting effect such as a reduction in the brains gray matter, decreased cognitive functions, memory loss, shortened attention span and Wernicke-Korsakoff.
Marijuana also have effects on the brain but interacts with different areas, most commonly the CB receptors, these are the receptors that absorb endocannabinoids. When we consume marijuana vs alcohol there is a large influx in the activation of the brains CB receptors, which results in the feeling of being “high”. When this happens the brains experiences things like mood swings, impairment, impaired memory and a change in cognitive ability, these are short term effects that only last a few hours. In terms of long term of effects of marijuana vs alcohol, cannabis shows few sings of any permanent long term effects, with short term memory loss being one of the common symptoms to regular marijuana use. This has lead to many misconceptions of marijuana providing a loss of brain cells, though studies are limited, evidence points to marijuana having no long term effects on the brain and that marijuana only effects the brain on a short term basis rather then a long term.