Dopamine, Motivation and Addiction

  Everything in our lives requires motivation. From getting out of bed to getting to work to going to the gym, we need motivation to accomplish all aspects of our lives. Motivation, indirectly, also drives our pursuit of pleasure and avoidance of pain. Not going to work, for example, would eventually cause emotional pain from either not making money or being fired. Going to the gym, while painful in the moment, brings pleasure from improved physiological health and strength gains. The balance of pleasure and pain in our brains is very delicate, primarily underpinned in the brain by a neurotransmitter called dopamine. Contrary to popular belief, though, dopamine doesn’t directly cause our feelings of pleasure. It is related to motivation, which in turn affects our reactions to events in our lives. Dopamine’s influence on personal drive is key to enhancing motivation and achieving goals, so let’s look at its functions in the brain related to addiction, procrastination, and maintaining pursuit of goals.

To start, I want to hammer home once again how dopamine isn’t the “pleasure chemical”. It’s a neuroactive regulatory chemical; which means it’s stimulating in nature, and it regulates neural pathways. Dopamine's role is not primarily about pleasure but is more focused on the desire and pursuit to reduce pain; as such, dopamine is often referred to as the substrate of motivation and movement toward pleasurable things. The release of dopamine in the brain is closely linked to the desire to exert effort. Some physiology: it operates through the mesolimbic pathway, consisting of the ventral tegmental area (VTA) and the nucleus accumbens. The prefrontal cortex regulates the timing and amount of dopamine release.

The rate of dopamine neuron firing remains low until we start thinking about or craving something. This can be as simple as food or coffee, or more complex desires, like romance or academic ambition. Anticipation and excitement can lead to a dramatic increase in the rate of dopamine firing, pushing individuals into action. Like, think about when you’re hungry. Imagining the food you want to eat will cause you to physically salivate, prompting you to seek food more intently. The amount of dopamine released will vary wildly based on what you’re seeking, of course. Sex, for example, doubles dopamine levels in the brain. Nicotine, cocaine, and amphetamines significantly spike dopamine as well, often more than doing the actual drug (we’ll come back to this idea later).

Let’s circle back to addition for a moment. I’m sure you’ve had a talk in primary school at some point about addiction (DARE program, looking at you). It was probably mentioned how one craves their substance of choice, and using that substance briefly suppresses this craving. Once the substance use stops, the craving quickly resumes. An interesting point on this, though, is that excessive engagement in addictive behavior results in pain. Wait, what? How can an addictive thing you love cause you emotional pain? Well, think about the inevitable part of every addict's story. At some point, they’ll hit a breaking point, and maybe reflect on the consequences of their addiction. At this point, they might try to seek treatment with varying levels of success. So why the change? You might also remember from drug prevention classes a graph of feelings of pleasure over time while using drugs. On the first usage, feelings of pleasure are the highest. This high, interestingly enough, is not what gets people hooked; it’s the depression after. They feel worse without the drug than they did prior to using it, thus they keep using it in order to avoid this depressed state. However, the more time goes on, the lower the highs get, and the worse the depressed states become. As Dr. Andrew Huberman notes, "Much of the pursuit of pleasure is simply to reduce pain”, which we see clearly here. Approximately 15-20% of people have a genetic predisposition toward addiction. Just something to remember.

Wait, so what’s with that crash, that depressed state? After a surge of dopamine release, another neurochemical called prolactin is released. The crash that follows intense dopamine release can be challenging to manage, hence why addiction is so prevalent. Prolactin is associated with feelings of letdown, postpartum depression, and more anticipation. It initially evolved for reproduction, causing lethargy and stillness after orgasm. It may feel unnecessary; like, why does our brain do this? Well, even too much of a good thing is bad, too. Without prolactin and dopamine cycling, we wouldn’t be able to maintain correct motivation to any degree. Everything would feel too important, and we couldn’t get anything done. There are ways we can mitigate prolactin crashes, actually. Certain nutrients like vitamin B6 and zinc can act as potent prolactin inhibitors. Extending the arc of positive experiences can also help offset the pain that follows dopamine release; so, avoiding quick fixes for happiness, essentially.

Now, onto another negative consequence of dopamine dysregulation; procrastination. And yeah, dopamine dysregulation is key to procrastination. Two types of procrastinators exist: those who thrive on the stress of impending deadlines, and those who struggle with releasing sufficient dopamine to initiate action. To combat procrastination, different approaches are required. For type 1 procrastinators, methods to induce epinephrine release, such as super oxygenation breathing or caffeine consumption, may be effective. For type 2 procrastinators, strategies to induce dopamine release, such as mucuna pruriens or certain antidepressants, can be beneficial. Essentially, our motivation needs to be tied to the pursuit as well as the final result. This shift in perspective can help us overcome procrastination and stay motivated. 

Dopamine works in conjunction with other neurotransmitters and chemicals. While dopamine leads us to focus on external goals and desires (things we don't yet have to chase), molecules like serotonin and cannabinoids encourage contentment in the present. Dopamine can sometimes make individuals relentlessly pursue their goals, even at the expense of ethics and morals, purely from feelings of anticipation. This is due to the fact that dopamine is deeply linked to the possibility and novelty within the brain. The reward-prediction error occurs when the actual dopamine release falls short of expectations. We can see this when individuals anticipate a reward that does not materialize, leading to a significant dopamine crash. Let’s do a quick surface skim on some behavioral psychology. 

Reward schedule experiments are a common technique used in behavioral psychology, neuroscience, and reinforcement learning to study how different patterns of rewards or reinforcements affect an organism's behavior. These experiments involve providing rewards or positive feedback to individuals or agents in various ways, and then observing how these reward schedules impact their learning, motivation, and decision-making. There are several types of reward schedules, including continuous, fixed-ratio, variable-ratio, fixed-interval, variable-interval, and intermittent schedules. Continuous reward schedule is when a reward is provided every time a specific behavior is exhibited. There are then fixed interval and fixed-ratio schedules, when a reward is given after a certain amount of responses or time has passed. Variable-ratio and ratio reward schedules are when rewards are given after an unpredictable number of responses or amount of time. Intermittent reward schedule is the combination of variable interval and ratio schedules. In intermittent schedules, rewards are not delivered every time a behavior occurs but are distributed unpredictably. This unpredictability often leads to persistent and high levels of responding because individuals or agents never know when the next reward will come. 

Intermittent reward is the most powerful, period. This is because the uncertainty and unpredictability of when the reward will be received create a strong motivation to continue engaging in the target behavior. Think about playing a slot machine or gambling, for example. You don't know when the next payoff will occur, which can be highly motivating. This is also associated with more risk taking; people are more willing to gamble if they think they’ll win big this time.

We can harness the power of intermittent reward in a positive way, though! To ensure consistent progress towards goals and avoid excessive reward conditioning, we can celebrate some wins, but not all of them. This intermittent approach reduces the impact of reward and prevents a significant dopamine crash, allowing us to remain on the path of higher goals. For example, don’t get a little sweet treat every time you get your work done on time. You’ll get burned out from this reward, and it won’t mean much to you anymore. Maybe go out for Starbucks only once a week, but only if you’ve stayed productive all week. This single reward will motivate your entire week of work, as opposed to ten different Starbucks trips for each time you complete an academic assignment. This is one way of many to use intermittent rewards to your advantage.

Overall, dopamine is often misrepresented in popular science. It isn’t the “pleasure” hormone, but rather our motivation towards pleasure. Its control over pleasure and pain directly affects our patterns of addiction, procrastination, and pursuit of goals. Using this information, I hope you can better understand your own patterns of impulse and discipline and perhaps change some behaviors for your own benefit.

Sources:

https://www.hubermanlab.com/newsletter/tools-to-manage-dopamine-and-improve-motivation-and-drive

https://www.nature.com/articles/s41583-021-00455-7

https://pubmed.ncbi.nlm.nih.gov/10896158/

https://pubmed.ncbi.nlm.nih.gov/29420469/

https://pubmed.ncbi.nlm.nih.gov/29398114/

https://pubmed.ncbi.nlm.nih.gov/9457173/

https://pubmed.ncbi.nlm.nih.gov/29760524/

https://pubmed.ncbi.nlm.nih.gov/24968237/