Stimulants, depressants, cocaine, LSD, heroin, ecstasy, cannabis and many other drugs all affect the brain: the command centre of your body. Illegal drugs affect our bodies in ways we cannot predict due to the sensitivity of this vital organ, and the adverse chemical reactions that occur when influenced by these drugs.
Breaking barriers for drugs is imperative; whether it’s illegal drugs crossing a country’s heavily guarded boarder, or once in the body, the brain's natural protective shield. Ultimately, access to the brain is vital for a drug to produce the ‘high’ that the user seeks.
The brain has a blood barrier made from lipids (fatty acid molecules) which hold back all the stuff we put in our bodies, helping to maintain a healthy working environment. Despite this, drugs with fatty acid groups incorporated into their structure, such as all psycho active drugs, can pass freely without much disruption; leaving the brain naked and exposed to all the drugs’ unpredictable affects.
Three primary areas of the brain are affected by drug abuse: the brain stem, the limbic system and the cerebral cortex. All of which play vital roles in the mental and physical well-being of the person.
The major reason that drug abuse can exert such powerful control over, and manipulate our behaviour, is that they directly affect and act on the more evolutionarily primal areas of the brain, the brainstem and limbic structures; this can override the cortex in controlling our behaviour. They then eliminate the most human part of our brain from its role in controlling our behaviour temporarily, making the user unaware of the implications of their actions and consequences for the people around them.
Cocaine is a strong central nervous system stimulant, affecting the levels of dopamine in the brain’s circuits by increasing them dramatically, creating cocaine’s characteristic high. Winning a prize or smelling good food usually causes dopamine to be released by the neurons into the circuits, creating a sense of euphoria. Therefore by stimulation of the reward system, cocaine provides the desired effect. When the drug molecules cross the blood brain barrier, it increases the synaptic activity of dopamine, stimulating the learning and reward system, and discharging norepinephrine, creating the feeling of hunger (the munchies). Cocaine use directly interferes with the verntral tegmenal areas of the brain and the nucles accumbens; these are areas in the mid brain. However, cocaine prevents the dopamine from being recycled, hence causing excessive amounts to build up in the synapses, amplifying the dopamine signal and ultimately disrupting the brain's normal circuits and consequently communication throughout.
Continuous drug use can cause physical changes in the brain affecting the psychological welfare of the user permanently. These changes can cause cravings and other problems controlling behaviour that make it difficult to decrease drug usage, disregarding the harmful consequences; this is addiction.
Marijuana, known as the ‘gateway drug’ holds this reputation due to the body’s ability to build up tolerances leading users to a need for a greater high, leading many onto cocaine. Many cocaine abusers report that they fail to achieve as much pleasure as the first time they did from their first exposure to the drug. Adverse psychological or physiological effects can occur due to an increase in dose, in an attempt to prolong the high due to the desensitization of the relevant synapses in the brain stimulated by drugs.