Understanding the Neurobiology of addiction
Natasha Jovic, Provisional Psychologist at PsychMed
Substance abuse or addiction disorder has shown to affect around 1 in 20 Australians. It is defined by a cluster of cognitive, behavioural and physiological symptoms where a person continues substance use regardless of significant substance related problems. These problems can include long-term damage to the brain, other organs and general health and wellbeing. It can severely impact your mental health as well as put you at risk of damaging relationships with family and friends, problems with employment and financial hardship.
Several factors can affect someone’s risk of developing substance use problems, including genetics, psychological and environmental risk factors, as well as the timing of exposure, type and frequency of the substance use.
So what is it that makes drugs so addictive? Why does it make recovery so difficult? To answer these questions, it is important to understand how addiction begins in the first place.
Brain Reward Circuit
Addictive substances have extremely strong effects on the brain. When someone is engaging in substance use, it activates the brain’s reward system, which results in intense feelings experienced. One of the primary areas of the brain which are involved in the rewarding effects of substance use is the nucleus accumbens. Through this reward circuit process, the nucleus accumbens releases excessive amounts of dopamine (the pleasure chemical), creating a connection between substance use and the feeling of pleasure. Research has shown that these same feelings of pleasure are produced by the reward circuit when we perform behaviours that are considered essential to survival (e.g. eating, sex, social interaction). The brain then rewards these activities and triggers the memory centre to recall the activities or experiences and environments that originally led to this reward.
Over time, just reminders or associations made with drug use such as people, places and moods can be enough to activate the dopamine system and trigger these powerful urges. This excessive release of dopamine along with other processes can lead to more changes in the brain, which strengthen substance seeking and compulsive use.
Once the intoxication stage is over, the user is left with withdrawal symptoms and negative effects when they are no longer taking the substance, which ultimately leads to reduction in sensitivity of the reward system to both substances and natural reinforcement. This means that in time, they become tolerant to the drug use and in turn seek higher dosages. The reward circuit becomes hyper stimulated and other pleasurable activities such as eating food or social interaction no longer have the same outcome. This can lead to developing a sense of general depression, as they no longer experience joy from previously enjoyable activities.
It is clear how substance use can essentially cause ‘hijacking’ of the reward system, leading to problematic changes in the brain neurochemistry. If you or a loved one are struggling with substance use, please contact our friendly team at PsychMed for more information on our addiction treatment programs or visit https://psychmed.com.au/alcohol-drug-programs/
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