Jump to content

Motivation and emotion/Book/2020/Habit versus addiction

From Wikiversity
Habit versus addiction:
What are the similarities and differences between habit and addiction?

Overview

[edit | edit source]

The difference between a habit and an addiction is hard to distinguish. Many researchers place the definition of behavioural addiction under compulsive disorders rather than identifying this disease as something debilitating on its own. It was only recently that the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) identified behavioural addiction as a disorder separate from substance use. Many interchange the term habit and addiction due to their similarities in their definitions; a repeated behaviour often occurring subconsciously. The main difference is that a habit can be both positive and negative, while an addiction can only have negative consequences.

This chapter discusses the similarities and differences of a habit and an addictions. It will identify the different types of addictions, show how a habit can be confused with an addiction and help the reader identify how to distinguish between the two. It explains different psychological theories used to identify different mechanisms involved in addiction and habit formation in the brain and the chemicals produced that can boost the prevalence of addiction in society.

Important points about this topic:

  1. A habit can be both positive and negative.
  2. An addiction can only be negative.
  3. The habit loop and breaking a habit.
  4. Different types of addictions.

What is a habit?

[edit | edit source]
A habit is a routine of behavior that is repeated regularly and tends to occur subconsciously.

Wendy Wood, a research psychologists, found that 40 to 45% of our daily behaviour are habitual, meaning almost half of our daily activities are performed by subconscious thinking. A habit is a routine, automated behaviour that is repeated regularly and tends to occur in the subconscious mind. A good example of a subconscious habit is driving, [grammar?] sometimes when driving, people forget exactly how they got to their location and that's because driving has become habitual to that individual.

You can have both good and bad habits. A habit can be summed up as a routine or regular behaviour that gets harder to give up the longer that behaviour goes on. Many habits can fall into the addiction category depending on the stage the individual is in. People tend to interchange the terms habit and addiction but there is one main difference between the two; habits can be either a negative or positive behaviour, while addictions are exclusively negative.

How long does it take for a habit to form?

Habits can form anywhere between 8 to 254 days; with the average time for most people being just 66 days[factual?].

When a habit is forming in the brain, neurons start to make weak connections with each other, and over time, those connections get stronger and thicker. These neuron connections are protected by a large layer of fat surrounding them called a myelin sheath.

How long does it take to break?

A habit can take roughly 21 days to break[factual?]. Habits that become a substitute for something else, such as when food becomes a comfort mechanism rather than nutrients, can be difficult to break without resolving the underlying reason it began. Studies show that once you identify a habit, you can change the behaviour to become more desirable[factual?]. You can achieve this by adopting the habit loop and following the golden rule: Keep the cue and reward while changing the routine!

The habit loop

[edit | edit source]

Every habit follows the same process, [grammar?] first there is the initiation of the cue, followed by the routine and then lastly, the reward:

THE CUE

A cue is some type of trigger that makes the behaviour unfold automatically, a trigger that makes your brain go into autopilot mode. Studies tell us that a cue can be a location, time of day, an emotional state, other people or just a behaviour that consistently triggers a certain routine[factual?].

THE ROUTINE

Also known as the behaviour itself, the routine is the process or activity that you perform almost automatically after you encounter the cue.

THE REWARD

The reward is the most important part, it's why habits exists[grammar?]. To achieve the reward but figuring out the reward is the hardest part[say what?]. It's what is achieved from the behaviour and compels the individual to continue the behaviour. It helps our brain to figure out if the behaviour is worth remembering for the future, [grammar?] it could be the feeling you get after eating something sweet or smoking a cigarette.

The more that we experience the three part loop, the more the process become automatic. The damaging factor is when the cue and reward start working together to form neurological cravings propelling us to undertake the routine in order to achieve the reward. Cravings are essentially the trigger to perform the habit loop. A craving works by reminding the brain of the pleasure previously experienced when the reward was gained, [grammar?] it experiences the same sort of pleasure response that is achieved when we encounter the reward. However, this causes a disturbance and the brain will actively seek out the routine to fix the disconnection between what our brain feels and what we're experiencing.

Reward circuits are crucial for human existence as they enable us to develop behaviours or routines that contribute to our survival.

Case Study: Part 1

Lucy is a 16 year old girl that likes to keep herself updated on all the latest trends and influencers on social media. She also has an Instagram account where she posts photos of many different things to show people what she is up too[spelling?]. Over the years, Lucy noticed that at a specific time of day, she tends to get more likes on her photos when those photos are of herself. So every week, Lucy starts going to different places wearing new clothes to take photos in. She then uploads those photos to her social media account at that specific time of day and waits for the ding from her phone saying she has a new like on her photo. The time of day is the cue, the photo being uploaded is the routine and the ding from her phone is the reward.

What is addiction?

[edit | edit source]
Addiction in basic terms is a physical or psychological need to do, take or use something, to the point where it has negative consequences.

The concept of addiction is not easy to define, and the usage of the term has been considered controversial and there isn't a set criteria in defining all instances, (Griffiths, 1996). Addiction is a complex condition and was also sometimes referred to as a substance use disorder before behavioural addiction was researched. Relinquishing control from the addicted person, or dependence on a substance or activity, is the central feature of many definitions. Addictions can be diagnosed as a neurological disorder described as an individual acting on compulsive engagements for rewarding stimuli. In most cases, an addiction is not developed overnight. Any behaviour can turn into an addiction and is caused by dopamine rush. A little burst of dopamine can cause an addiction[factual?].

The three C's[grammar?] are used to help distinguish between a habit and an addiction. Control, Cravings and Consequences[grammar?]. Addiction is the loss of control over oneself and/or the use of a substance to aid the addiction. A craving is when the desire for a substance becomes more of a necessity or a survival instinct over a behavioural habit or stress reliever and when negative consequences become apparent, yet the individual still continues with the addiction.

Understanding what makes an addiction and what constitutes a behaviour to fall into the category of addiction is crucial for future research into addiction and to not take steps backwards into identifying addiction as merely an impulse control disorder. Many researchers are identifying common behavioural traits and trying to place them under the addiction subheading which can lead to the relevance and credibility of the field of addiction into question, (Kardefelt-Winther et al, 2017).

Substance use disorder

[edit | edit source]

Dopamine

Dopamine functions as a neurotransmitter in the brain and is associated with 'reward-motivated' behaviour. It is a chemical that is released in the brain, also known as the 'feel-good' neurotransmitter that relays feelings of pleasure when we engage in pleasurable behaviours or activities. The brain releases it when we eat food that we crave or while we have sex, contributing to feelings of pleasure and satisfaction as part of the reward system. The idea is that reward circuits make us feel good when we do something for our survival, like eating when hungry, drinking when thirsty, making the reward circuits or system critical to human survival. We want to feel good so that we participate in these survival activities.[factual?]

'While human beings inherently rely on dopamine to reinforce survival behaviours such as eating and procreating, this brain chemical also happens to be the key player in addiction. (Shelly Tichelaar, 2017)'.

Drug addiction

Dopamine is involved in drug reinforcement but its role in addiction is less clear. In 1994, two neuroscientists, Drs Volkow and Schelbert, performed PET scans on the brains of addicted individuals to determine the effects of dopamine levels on excessive drug use.

They found two parts responsible for the release of dopamine, the limbic and cortex system. These systems are responsible for the basic survival instincts and the dopamine released, this release is transmitted to the amygdala and hippocampus which records the 'feel-good' emotions, encouraging us to seek it again, this is known as survival hardwiring. There was a distinct difference in the pre-frontal cortex in drug addicts, which is responsible for decision making and impulse control.

Drugs and alcohol activate the same dopamine processed[spelling?] in the survival centre of the brain, causing repeated use of the substance to gain the 'high' of experiencing the dopamine release. The substance essentially hijacks the brain, weakening the system and making the primary need the substance. However, more and more of the substance is needed to create and activate the same level of reward or feelings of pleasure, causing tissue damage in the brain.[factual?]

Dopamine is considered crucial for the rewarding effects of drug abuse. Drugs, seemingly by accident, activate the same regions of the brain that release dopamine into our systems, causing the 'feel-good' survival instincts.[factual?]

'Behavioural science experts believe that all entities capable of stimulating a person can be addictive; and whenever a habit changes into an obligation, it can be considered as an addiction, (Alarvi, et.al, 2012)'.

Behavioural addiction

[edit | edit source]

Addiction has only recently being[spelling?] recognised as more than a substance use disorder and is not restricted to just drug-ingestion behaviours. A behavioural addiction is like a substance addiction, [grammar?] it produces a short-term reward which may result in persistent repeated behaviour. This creates a failure to resist impulse and a temptation or drive to perform an act that is harmful to the individual or to others (American Psychiatric Association, 2000). The individual's repetitive engagement in the behaviour ultimately effects[grammar?] the outside domains and life. Behavioural addiction has historically been conceptualised in several ways. Some view it on the compulsive-impulsive spectrum and others view it as an impulse control disorder where it was finally idealised as non-substance or 'behavioural'. Trying to distinguish between what is an behavioural addiction and what fits into an impulse control disorder is up for debate (Grant, Potenza, Weinstein & Gorelick, 2010). The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) identified gambling as a behavioural addiction and has created a category in the manual for those suffering from this dependence, allowing those to gain treatment and services that they need. (American Psychiatric Association, 2013).

Not all behavioural addictions can be categories[spelling?] as impulse control, but most impulse control disorders share key features with behavioural addictions. The most common feature in understanding the difference is, [grammar?] people that engage in a behavioural addiction get some form of gratification after the behaviour has been performed while those with obsessive-compulsive disorders don't receive any pleasure after their behaviour.

Examples of a behavioural addiction: gambling, internet usage, nail biting, skin picking and compulsive buying.

Case Study: Part 2

Lucy notices that her photos don't get as many likes as they used to. So she starts uploading more photos of herself in new clothes more days a week. Lucy starts obsessing over her phone and social media, looking at other peoples photos for inspiration and searching for what may get her more likes on her photos. She starts borrowing money from her parents to be able to buy more clothes. Instead of doing homework after school, she forces her friends to go out with her to take photos of her posing in her new clothes. She starts watching her phone after she posts a photo, waiting for the notification and ding to alert her she has another like. Lucy starts becoming addicted to her phone and to her social media account.

How a habit turns into an addiction

[edit | edit source]
Figure 1. Nail biting can be both a habit and an addiction.

Anyone can become addicted to something, [grammar?] no one is immune. To most, addiction serves a purpose, initially a certain behaviour starts as a technique to reduce stress, e.g. a glass of wine after a long day at work or playing computer games when you get home from school. It is important for individuals to be able to identify habits so they can have awareness of keeping good habits and eliminate bad ones; as bad habits have the potential to turn into an addiction and cause negative consequences. An addictions is an overexpression of a behaviour that turns into something negative, meaning the overuse of a bad habit can in turn create a negative side effect.[factual?]

A habit can turn into an addiction when the individual begins having dependence issues, creating a physiological component. In terms of substance use, more and more of the substance is required to reach the reward gained initially from the routine. If the demand for the substance isn't met it can lead to withdrawal symptoms, [grammar?] these include 'physical and mental symptoms that occur after stopping or reducing intake of a drug, (Mayo Clinic, 2017).' Withdrawal has the ability to interfere with the individual's life and mindset.[factual?]

Psychological theories

[edit | edit source]

In psychology, 'theories are used to provide a model for understanding human thoughts, emotions, and behaviours, (Cherry, 2020).' The theories share an insight into intrinsically fascinating ideas concerning psychological aspects of the human development including thinking, perception and learning. The use of psychological theories can be beneficial in understanding the very confusing world of addiction and habits as definitions get remastered and replaced with new ones, the motivation can influence addictive behaviours in individuals.

Drive reduction theory

[edit | edit source]

The Drive Reduction Theory (Clack Hull, 1943), acts on the body's need for homeostasis and its necessitate to resolve the deviation from homeostasis causing physiological needs. This in turn creates a psychological drive. Homeostasis is the bodies need to maintain and achieve equilibrium or a balanced internal state, e.g. your body regulating internal body temperature to ensure you don't become too hot or too cold. This can be linked to the survival instincts that the body uses to help maintain homeostasis in the body, such as the basic survival needs (food, thirst and sex). These needs result in a psychological drive that initiates a behaviour to meet the need and, ultimately, return the system to homeostasis. According to the theory, the reduction of drives is the primary force behind motivation. A drive creates an unpleasant state, a tension that needs to be reduced and the body is motivated to engage in whatever behaviour is necessary to fulfil an unsatisfied drive.

Arousal theory of motivation

[edit | edit source]

Building from the Drive Reduction Theory, the Arousal Theory of Motivation (Yerkes & Dodson, 1908) can be link to the habit loop, as it links levels of arousal as potential motivators to eliminate psychological drive. One way the body elicits this behavioural motivation is by increasing physiological arousal. The theory uses the neurotransmitter chemical, dopamine, as a primary factor for motivation in the body.

The Arousal Theory is described as the body being motivated to engage in a behaviour to fulfil an unsatisfied drive, i.e. the cravings elicit by the cue and reward in the habit loop to force the brain to undergo the routine to achieve the reward.

An experiment, conducted by Peter Milner and James Olds in the early 1950s, involved a rat that was placed in a box with two levers. One releasing food and water for the rats survival and the other releasing a brief stimulus to the reward centre of the brain, which results in a release of dopamine into the rats system. Findings showed that the rat would repeatedly press the reward stimulus lever over and over, becoming so involved that it would forget about the food and water lever. It would continue to press the rewards lever until it collapsed from exhaustion. This study provided evidence that animals are motivated to perform behaviours that stimulate dopamine release in the reward centre of the brain.

This experiment contradict{{gr} the theories of Freud (1915) and Hull's (1943) drive theory and Maslow's hierarchy of needs (1943) which state that basic biological needs will overpower motivation and psychological urges or cravings.

Excessive appetite model

[edit | edit source]

The main idea of the Excessive Appetite Theory (Jim Orford, 1985), is that addictions are a type of extreme appetites, rather than a form of dependency, as seen with substance abuse. It is one of the strongest theories that support the existence of behavioural addictions. This theory tries to change the view of addiction from a substance use disorder, to more of a behavioural based identification. Having addiction identified only as substance abuse has a negative impact on people suffering from a behavioural addiction 'who might be in need of help in overcoming an excessive appetite, but in my view it has very seriously biased our theoretical understanding, (Orford, 2000).

The theory has 5 main appetites:

  1. Drinking alcohol
  2. Drug taking
  3. Eating
  4. Exercise
  5. Gambling

The Excessive Appetite Model differs from the previous theories in two main ways:

  • Addiction is described as a largely psychological process, rather than a physical disease.
  • Addiction can occur in response to a wide range of different behaviours, not just to alcohol and other drugs, which predominate work on addiction, (Hartney, 2020).

The previous theories used brain instincts and dopamine releases to explain addiction, where as Excessive Appetite focuses on cravings motivating addiction. Many have tried to discredit the theory by stating that individuals can be addicted to everyday activities or habits that have no negative consequences associated with them, such as brushing teeth, or doing a crossword. The theory however, identifies that an addiction has a negative consequence whether to the individual themselves or the people around them.

Is your behaviour a habit or an addiction?

[edit | edit source]

It's difficult to distinguish between an unhealthy habit and an addiction but having the awareness to identify if you have an addiction or a bad habit can help eliminate either when things get tough.

'The lowest smoking prevalence aggregated for studies reported in any single year was 65%, (Guydish, et al, 2011).' 'The prevalence of social computer game users (55.2%) and Internet addiction (58.9%), (Thomas & Heritage Martin, 2010).' 'Alcohol was the leading drug in 2018-2019 that individuals sort out treatment for (36%), (Australian Institute of Health and Welfare, 2020).'

A study conducted by Sussman, Lisha and Griffiths showed the prevalence of 11 potential addictions in society (tobacco, alcohol, illicit drugs, eating, gambling, Internet, love, sex, exercise, work, and shopping). These were chosen due to results found in previous research experiments. Results from the study showed that among U.S. adults, over a 12-month observation period, prevalence varied from 15% to 61%. It was estimated that a plausible 47% of the U.S. adult population presented with maladaptive signs of an addictive disorder over the 12-month period, (Sussman, Lisha & Griffiths, 2010)

With an increasing number of studies surrounding addiction and their prevalence in society, it is estimated that a higher number of people suffering from an addiction are being recorded for each experiment conducted. With the new identification for addiction being produced by the DSM-5, many that suffer from an addiction and not a compulsive disorder will get transferred to the new identification under the DSM-5 and the numbers surrounding prevalence will change.

Signs your habit is becoming an addiction:

  • Experiencing cravings
  • Negative consequences occurring after behaviour is performed
  • A loss of control over motivation - a need to perform the behaviour
Case Study: Addiction

Lucy had to increase her behaviour to achieve the same level of dopamine release in her brain. Lucy became addicted to the dopamine release caused by the ding emitted from her phone after she performed her behaviour or routine of uploading a photo to her social media platform.

Test Your Knowledge!

Choose the correct answers and click "Submit":

1 what % of behaviours a day are identified as habits?

10-20%
30-35%
40-45%
60-70%
80-85%

2 In the case study, what does Lucy have?

a good habit
an addiction
a bad habit
Lucy doesn't have either an an addiction or a habit

Conclusion

[edit | edit source]

The easiest distinguisher between a habit and an addiction is the negative consequences associated with addictions. A habit can be both good and bad while an addiction can only have negative consequences, even if the individual doesn't believe their addiction is undesirable. Addiction, in today's context has connotations to behavioural routines and substance use. A habit is classed as a repetitive behaviour often performed autonomously. An addiction is a craving that drives that certain behaviour to be performed. Both are run by the habit loop; a cue, a routine and then the reward. The only difference is when the cravings become overwhelming and interrupt the individual's thoughts and daily activities.

A habit can be broken by identifying the reward gained from the behaviour and breaking the habit loop. Switching a bad habit for a good one can help stop the progression to an addiction causing negative consequences for the individual and those around them.

See also

[edit | edit source]

References

[edit | edit source]
Addiction Policy Forum. (2019, April 16). What is Addiction? [Video]. YouTube. https://www.youtube.com/watch?v=2s727i3uEjY

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596

Alavi, S. S., Ferdosi, M., Jannatifard, F., Eslami, M., Alaghemandan, H., & Setare, M. (2012). Behavioral Addiction versus Substance Addiction: Correspondence of Psychiatric and Psychological Views. International journal of preventive medicine, 3(4), 290–294.

Australian Institute of Health and Welfare. (2020). Alcohol, tobacco & other drugs in Australia. Retrieved from https://www.aihw.gov.au/reports/alcohol/alcohol-tobacco-other-drugs-australia

Cherry, K. (2020). Biography of Influential Psychologist Clark Hull. Verywell Mind. https://www.verywellmind.com/clark-hull-biography-1884-1952-2795504

Citytv. (2014, November 24). Bad Habit or Addiction? [Video]. YouTube. https://www.youtube.com/watch?v=x90iyjLVrYc

Clancy, C. (2020a). Addiction vs Habit: Recognizing the Dangers. JourneyPure. https://journeypureriver.com/addiction-vs-habit/

Clancy, C. (2020b). Habit vs. Addiction: 4 Questions To Determine The Difference. Journey Pure. https://journeypureriver.com/habit-vs-addiction-4-questions-determine-difference/

Department of Health & Human Services. (2020, March 19). Addiction. Better Health Channel. https://www.betterhealth.vic.gov.au/health/HealthyLiving/Addiction

Drug addiction (substance use disorder) - Symptoms and causes. (2017, October 26). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/drug-addiction/symptoms-causes/syc-20365112

Grant, J. E., Potenza, M. N., Weinstein, A., & Gorelick, D. A. (2010). Introduction to Behavioral Addictions. The American Journal of Drug and Alcohol Abuse, 36(5), 233–241. https://doi.org/10.3109/00952990.2010.491884

Griffiths, M. (1996). Behavioural addiction: an issue for everybody? Employee Counselling Today, 8(3), 19–25. https://doi.org/10.1108/13665629610116872

Guydish, J., Passalacqua, E., Tajima, B., Chan, M., Chun, J., & Bostrom, A. (2011). Smoking Prevalence in Addiction Treatment: A Review. Nicotine & Tobacco Research, 13(6), 401–411. https://doi.org/10.1093/ntr/ntr048

Hartney, E. (2020). Excessive Appetites Is a Controversial View of Addictions. Verywell Mind. https://www.verywellmind.com/excessive-appetites-22259

How Addiction Happens. (2017, October 16). How Addiction Happens [Video]. YouTube. https://www.youtube.com/watch?v=HDfSx_Q7_Yk&t=253s

How Theories Are Used in Psychology. (2020). Verywell Mind. https://www.verywellmind.com/what-is-a-theory-2795970#:%7E:text=In%20psychology%2C%20theories%20are%20used,thoughts%2C%20emotions%2C%20and%20behaviors.&text=A%20psychological%20theory%20has%20two,make%20predictions%20about%20future%20behaviors

Kardefelt-Winther, D., Heeren, A., Schimmenti, A., van Rooij, A., Maurage, P., Carras, M., Edman, J., Blaszczynski, A., Khazaal, Y., & Billieux, J. (2017). How can we conceptualize behavioural addiction without pathologizing common behaviours? Addiction, 112(10), 1709–1715. https://doi.org/10.1111/add.13763

Kranzler, H. R., & Li, T. K. (2008). What is addiction?. Alcohol research & health : the journal of the National Institute on Alcohol Abuse and Alcoholism, 31(2), 93–95.

Kuhar, M. (2020). Dopamine, Reward, & Survival. Coursera. https://www.coursera.org/lecture/addiction-and-the-brain/dopamine-reward-survival-Am6cy

McKay, K. B. (2020, September 26). Unlocking the Science of Habits: How to Hack the Habit Loop & Become the Man You Want to Be. The Art of Manliness. https://www.artofmanliness.com/articles/power-of-habits/

O. (2019, September 26). Habit vs. Addiction: What’s the Difference? Alvernia Online. https://online.alvernia.edu/articles/habit-vs-addiction/

Ohio State Wexner Medical Center. (2015, August 26). Addiction versus a habit or urge [Video]. YouTube. https://www.youtube.com/watch?v=VL3Y6kvDk64

Orford, J. (2001). Addiction as excessive appetite. Addiction, 96(1), 15–31. https://doi.org/10.1046/j.1360-0443.2001.961152.x

Ostlund, S. B., & Balleine, B. W. (2008). On habits and addiction: an associative analysis of compulsive drug seeking. Drug Discovery Today: Disease Models, 5(4), 235–245. https://doi.org/10.1016/j.ddmod.2009.07.004

Pyramid Healthcare. (2019, January 4). Habit or Addiction? https://www.pyramidhealthcarepa.com/habit-or-addiction/

Psychological Theory - an overview | ScienceDirect Topics. (2020). ScienceDirect. https://www.sciencedirect.com/topics/psychology/psychological-theory

Seo, D. B., & Ray, S. (2019). Habit and addiction in the use of social networking sites: Their nature, antecedents, and consequences. Computers in Human Behavior, 99, 109–125. https://doi.org/10.1016/j.chb.2019.05.018

Studer, B., & Knecht, S. (2016). Motivation: What have we learned and what is still missing? Motivation - Theory, Neurobiology and Applications, 441–450. https://doi.org/10.1016/bs.pbr.2016.07.001

Substance-Related and Addictive Disorders. (2013). Psychiatric News, 48(8), 5–22. https://doi.org/10.1176/appi.pn.2013.4b13

Sussman, S., Lisha, N., & Griffiths, M. (2010). Prevalence of the Addictions: A Problem of the Majority or the Minority? Evaluation & the Health Professions, 34(1), 3–56. https://doi.org/10.1177/0163278710380124

Sussman, S., & Sussman, A. N. (2011). Considering the Definition of Addiction. International Journal of Environmental Research and Public Health, 8(10), 4025–4038. https://doi.org/10.3390/ijerph8104025

TEDx Talks. (2018, January 9). The Science of Habits | Marco Badwal | TEDxFS [Video]. YouTube. https://www.youtube.com/watch?v=FSZyzhi8C9o

The Arousal Theory and Our Individual Behaviors. (2020). Verywell Mind. https://www.verywellmind.com/the-arousal-theory-of-motivation-2795380

Thomas, N., & Martin, F. H. (2010). Video-arcade game, computer game and Internet activities of Australian students: Participation habits and prevalence of addiction. Australian Journal of Psychology, 62(2), 59–66. https://doi.org/10.1080/00049530902748283

Volkow, N. D., Fowler, J. S., Wang, G. J., Baler, R., & Telang, F. (2009). Imaging dopamine’s role in drug abuse and addiction. Neuropharmacology, 56, 3–8. https://doi.org/10.1016/j.neuropharm.2008.05.022

Volkow, N. D., Wang, G.-J., Fowler, J. S., Tomasi, D., & Telang, F. (2011). Addiction: Beyond dopamine reward circuitry. Proceedings of the National Academy of Sciences, 108(37), 15037–15042. https://doi.org/10.1073/pnas.1010654108

Yerby, N. (2020, September 18). Addiction Statistics - Facts on Drug and Alcohol Use. Addiction Center. https://www.addictioncenter.com/addiction/addiction-statistics/

[edit | edit source]