Decoding Dopamine: The secret to your well-being and productivity

Researcher: Bill Nguyen 

Research Editor: Linette Borges

If you have been looking for productive tips, you have probably gone through a concept called “dopamine addiction” – The idea that your neuron cells have been desensitized to dopamine created by internet exposure, so you require a higher dose of dopamine to activate them – but is it a thing? Well, not completely. In this blog, we will explain some biological functions of dopamine, and how it is involved in habit formation. Furthermore, we will bust some myths about dopamine addiction. What is Dopamine?

• Dopamine is a catecholamine neurotransmitter that mediates a wide range of physiological functions, from voluntary movement, reward pathway, hormonal regulation, and hypertension, when bound to its dopaminergic receptor on postsynaptic neurons (Beaulieu & Gainetdinov, 2011). 

• In this blog, we will focus more on the reward pathway of dopamine, which allows your brain to predict the reward and reinforces the actions.

• The reward pathway: the dopaminergic neurons in substantia nigra (SNc) and ventral tegmental area (VTA) in the midbrain release dopamine into the dorsal striatum of the brain, which underlies reward processing and reinforcement learning (Arias-Carrión, 2010). 

Figure 1. The anatomy of the reward pathway (Arias-Carrión, 2010) How is dopamine involved in forming new habits? 

• Start with an action that leads to a reward, when the reward is achieved, dopamine is released. If the reward is higher than expected, the dopamine response is stronger (Schultz, 2016).

• This leads to reinforcement to achieve that reward and dopamine response again (Schultz, 2016). 

• Gradually, dopamine is shifted from reward-oriented to action-oriented, meaning that if an action repeatedly leads to the reward, the behaviour will stimulate dopamine release  instead of waiting for the reward itself  (Schultz, 2016). 

• In the dorsal striatum, the reinforced action will be encoded to an automatic process as a mental shortcut to save deciding time and energy (Yin & Knowlton, 2006).

How is the dopamine level affected in internet addiction cases?

• A study in 2012 by Hou et al. indicated that being extensively addicted to internet usage, such as gaming, social media uses can cause partially similar patterns seen in drug addiction. However, the influence of internet addiction is much lower than that of drug addiction.

• When the brain is exposed to an extensive amount of dopamine, it will try to maintain the homeostasis by reducing the availability of dopamine receptors on postsynaptic neurons, which overall reduce the dopamine intake of the neurons.

• Specifically, Hou et al., 2012 stated that:

  • Glucose metabolism during resting is decreased in multiple regions that receive dopamine, such as striatum and orbitofrontal region, leading to decreased normal brain function

  • There is an increased change in genes coding for dopamine D2 receptor and dopamine degradation enzymes. 

  • From PET scan (imaging study technique), a decrease in dopamine D2 receptors in internet addiction cases compared to people within the same age group was observed.

• In general, all the changes of the neurons are associated with a decrease of dopamine uptake, as well as decreased brain functions such as logic and decision making during resting state. 

Busting myth about dopamine?

Myth #1: Dopamine is the “pleasure chemical”

• Not quite, people usually say that dopamine will make you feel good and motivated, however, this is oversimplified. Dopamine is involved with motivating and reinforcing actions that can bring you rewards, like a pleasured or happy feeling, but it does not directly make you feel pleasured.

Myth #2: You can get dopamine addiction

• Not literally, this is not like substance addiction, such as drug addiction. Dopamine is a natural neurotransmitter produced endogenously. It participates in the pathway that makes you think that an action is worth repeating as it can lead to a reward. 

Myth #3: Dopamine detox in a few days can reboot your brain

• The word detox is exaggerating, your brain constantly produces dopamine for movement. The idea that avoiding stimulation for a short period like 1 or 2 days can reset your dopamine system is not supported by neuroscience. Dopamine levels are tightly regulated and do not simply “drain” or “reboot” like a battery.

In a nutshell, now that you know how dopamine works, try to create a new habit by coupling a “reward” with an action. Furthermore, by being aware of your actions such as doomscrolling or internet usage, you can easily change your actions, and become more productive.

References:

Arias-Carrión, O., Stamelou, M., Murillo-Rodríguez, E., Menéndez-González, M., & Pöppel, E. (2010). Dopaminergic reward system: A short integrative review. International Archives of Medicine, 3(1), 24. https://doi.org/10.1186/1755-7682-3-24  

Beaulieu, J.-M., & Gainetdinov, R. R. (2011). The physiology, signaling, and pharmacology of dopamine receptors. Pharmacological Reviews, 63(1), 182–217. https://doi.org/10.1124/pr.110.002642

Hou, H., Jia, S., Hu, S., Fan, R., Sun, W., Sun, T., & Zhang, H. (2012). Reduced striatal dopamine transporters in people with internet addiction disorder. Journal of Biomedicine and Biotechnology, 2012, 1–5. https://doi.org/10.1155/2012/854524   

Schultz, W. (2016). Dopamine reward prediction error coding. Dialogues in Clinical Neuroscience, 18(1), 23–32. https://doi.org/10.31887/dcns.2016.18.1/wschultz  

Yin, H. H., & Knowlton, B. J. (2006). The role of the basal ganglia in habit formation. Nature Reviews Neuroscience, 7(6), 464–476. https://doi.org/10.1038/nrn1919