Drug addiction, otherwise known as substance use disorder, is defined as a mental disorder that causes an individual to compulsively consume a substance and can also be indicated by the voluntary misuse and abuse of drugs or substances despite the severe negative side effects it has on an individual. This...
Drug addiction, otherwise known as substance use disorder, is defined as a mental disorder that causes an individual to compulsively consume a substance and can also be indicated by the voluntary misuse and abuse of drugs or substances despite the severe negative side effects it has on an individual. This disorder can also lead to relapse (Jian-Feng Liu, Jun-xu Liu., 2018)1 which is the deterioration of an individual’s well-being. It impacts 3.2 million (Public Health., 2017) adults which ultimately means the majority of people with this disorder are not completely treated. It is a mental disorder that can either be due to neurobiology or due to a psychological aspect or both, so a variety of treatments have been introduced to treat it. Drug addiction is not proven to be cured but can be treated either using pharmacological treatments or behavioral treatments.
On the one hand, drug addiction can be due to psychological and emotional aspects such as the use of positive and negative reinforcement. This disorder compels individuals to move from the impulsivity to compulsivity domain where the drive for drug-seeking behavior changes from positive to negative reinforcement (George F. Koob., 2011)2. In the impulsivity domain, it is mainly related to positive reinforcement as before the impulsive act tension or arousal occurs and then pleasure, relief, or gratification is felt after the impulsive act. This feeling of euphoria positively reinforces the individual to repeat this behavior. In the compulsivity domain, it is mainly associated with negative reinforcement as persistent and reoccurring thoughts lead to anxiety or stress which leads to repetitive behavior and the removal of the anxiety or stress. Abstinence also negatively reinforces the individual and leads to drug addiction. This continuous cycle of impulsivity and compulsivity eventually leads to addiction (George F. Koob., 2011)2. This shows that individuals develop this mental disorder due to the fact that firstly they gain a sense of relief from consuming drugs and then when a stressful situation arises, it removes that stressful feeling. This constant cycle reinforces the idea that the drug is the source of reward as well as the source that eliminates the discomfort, therefore leading to compulsive drug-seeking behavior.
On the other hand, the neurobiology and neural network system of an individual also contribute heavily to the development of this mental disorder. The limbic system, which is buried under the cortex (Bailey Regina., 2018)4, consists of many neural structures such as the hippocampus, the amygdala, the striatum, and the nucleus accumbens. The nucleus accumbens is predominantly known to mediate the effects of drugs (Barry J. Everitt., Trevor W. Robbins., 2006)3. The limbic system contains a reward circuit that links together a plethora of brain structures that monitor and regulate an individual’s ability to feel pleasure. This feeling of pleasure motivates an individual to carry out the behavior and repeat it. The reward activates cells in the ventral tegmental area. The projection of the ventral tegmental area then travels to an area called the ventral striatum. The activation of these cells rapidly reaches a part of the ventral striatum called the nucleus accumbens which is the brain’s pleasure center. When the nucleus accumbens is activated, this causes cells to generate electrical signals which release molecules such as neurotransmitters as chemical messengers. In the reward pathway, dopamine is the neurotransmitter that is released and passes across the synapse3. There are specific receptors on the receiving neuron that help dopamine bind to them so interior proteins within the neuron can carry the signal forward. An excess of dopamine causes the molecules to remain free in the synapse where they either remain or are taken back up into the presynaptic neuron. The brain always has a healthy amount of dopamine in the synaptic gap even in the absence of a reward. When a reward is present, the presynaptic neuron generates and releases a large amount of dopamine which increases the level of dopamine in the synaptic gap. The dopamine transporters quickly return the dopamine levels back to normal by taking them back up. This all occurs in the ventral striatum. When an individual first consume a drug, for example, cocaine, it blocks the dopamine transporters on the presynaptic neuron so dopamine can no longer re-enter the presynaptic neuron. This increases the levels of dopamine in the synaptic gap, leading to a sensation of euphoria. This creates a significantly strong association between cocaine and pleasure, reinforcing the individual to repeat this behavior (George F. Koob., 2011)2.
There are pharmacological and behavioral treatments available to treat this mental disorder. Pharmacological treatments target specific receptors related to the drugs that are being misused. Dopamine is known to be the primary compound that is involved in an individual forming an association with drugs and pleasure. Dopamine receptors in the brain have different subfamilies that can be useful in producing medication to target the way drugs work alongside the neural networks (Jian-Feng Liu, Jun-xu Liu., 2018)1 . This can be useful in developing treatments for drug addiction because knowing what neural systems and networks are involved in the development of this compulsive behavior will make it easy to do so as you can specifically target the root cause by counteracting the change in the biology of the individual caused by the drug. Antagonist medications are being used to act upon the complementary neurotransmitter system as the drug of abuse and prevent the effect of these drugs5. It is known that drugs increase the dopamine levels in the synapse which results in the feeling of pleasure and euphoria, hence leading to addiction. Antagonist medications, such as naltrexone for alcohol dependence, are clinically proven to reduce the effect of morphine and heroin by blocking the receptors in the brain after binding to them6.
Behavioral treatments have also been effective in treating drug addiction. Cognitive Behavioural Therapy (CBT) is a form of talking therapy that challenges the negative thoughts and behavior of an individual with a mental disorder. CBT is known to be the most effective form of therapy which eliminates negative assumptions and behavior for a variety of mental health disorders. CBT has the potential of treating drug addiction as it focuses on the reversal of compulsive beliefs and behaviors that result from drug consumption. However, since drug addiction affects 3.2 million adults (Public Health., 2017) it means that the cost of CBT will be highly expensive and require many specialists to carry out the therapy which is impossible. Another form of behavioral therapy to tackle drug addiction is CET which mentions that drug addiction can be linked to Pavlovian conditioned learning which influences cue-induced cravings and drug-seeking behavior. This form of therapy includes repeated exposure to these cues which leads to extinction and that will eventually lead to the reduction of drug consumption1. Nevertheless, the efficacy of CET in treating drug addiction has not shown positive results compared to other mental disorders.
Drug addiction is a unique and complicated mental disorder that has no effective cure but has a few treatments that can reduce the impact that the drugs have on an individual. As the mechanism of drugs on the brain and body is known, it has made it easier to develop medication and therapy to reverse the way the drug works in order to reduce its impacts of it. Although, these methods may be effective, around 50% of individuals relapse prior to completion of the treatment (National Treatment Agency and Department of Health, 2017). Thus, highlights that although the biological and psychological reasons for drug addiction are known, and treatments are available, drug addiction can not be completely cured due to the long-lasting effects in the future.
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