Beyond Dopamine Nation: Towards a Fuller Picture of Addiction and Recovery
Dopamine Nation by Anna Lembke has become an almost inescapable text in the past few years, even to those who have not read it. Thanks in large part to her and the book, awareness of the role of dopamine release and the concept of “dopamine fasting” has entered popular consciousness, reaching far beyond the book-reading public. There is good reason for the book’s popularity and reach. It provides a straightforward non-technical description of addiction and some of the mechanisms behind it. The book also resonates with the current zeitgeist around a realization that it is all too easy to dip into overconsumption in our modern era, and it is true that dopamine plays an important role in our current cultural predicament.
At the same time, the book also suffers from a few oversimplifications which I worry can potentially do more harm than good. The biggest of which is the reduction of a vast array of complex neurobiology to a simple story about dopamine. I’ve come across countless instances of people using the phrase “dopamine hit” to refer to feelings as diverse as pleasure, joy, happiness, excitement, engagement, peace, etc. In this article I want to try to expand a bit on Lembke’s account in a couple of important ways that ultimately allow us to better understand ourselves, our experience, and the dynamics of addiction than a limited focus on just dopamine can allow. The main takeaway is the other neuromodulators aside from dopamine matter too! To learn why, read on.
Book Overview
It is worth first highlighting the strengths of the book a little more. Lembke, a professional psychiatrist, starts off the book discussing her interaction with a patient that had a sex addiction. Her tone is thoughtful, compassionate, and non-judgmental. This sets the stage for one of the main themes of the book, which is that any reinforcing behavior can become addictive, and that the mechanism by which this takes place is through the release of dopamine within the brain. She uses her experience working with this patient as a launching point from which to explore the ways in which modern post-industrial society is filled with stimuli which are capable of inducing these kinds of behavioral addictions. Lembke even goes so far as to discuss her own behavioral addiction to reading erotic fiction.
The problem with the story that Lembke tells in Dopamine Nation is that it is just a little too simple to really capture the complexity of what is going on inside our nervous systems when we engage in potentially addictive behaviors. To begin with, it is true that dopamine, a tiny molecule released in the brain, is the primary neuromodulator driving the reinforcement of behavior. Just considering dopamine alone however does not explain why people seek certain kinds of experiences or drugs in the first place. By expanding the conceptual framework just a little bit to include the role of other neuromodulators, we can get a much better grasp on how and why people become addicted as well as how best to help people recover from addiction.
The See-Saw Metaphor of Homeostasis
Lembke makes great use of a see-saw metaphor to elucidate the ways in which the brain seeks to maintain homeostasis or balance over time. In the metaphor, a given neuromodulatory system, like dopamine, works like a children’s see-saw with two sides: one for pleasure and the other for pain. Engaging in pleasurable experiences temporarily puts weight on the pleasure side. The brain, seeking to maintain homeostasis, triggers a balancing reaction which weighs down the pain side in order to equal things out again. That response on the pain side can often last longer than the effect on the pleasure side. This is because the nervous system assumes that the increase on the pleasure side reflects a “new normal” that it needs to adapt to. Rather than just responding to the past, the brain is also trying to predict the future. This is an important concept that will come up again later.
The extra weight on the pain side helps to explain why people often find themselves taking larger and larger doses of a drug over time, or seeking more extreme forms of experience in order to maintain the original high they experienced. This metaphor of the balancing see-saw is used by Lembke to explain the concept of downregulation, a process whereby the brain releases less of a neuromodulator or potentially expresses fewer receptors for that neuromodulator.
While this account is correct in general, there is some lost nuance in the language that Lembke uses to describe it. Although she calls the two sides of the see-saw pleasure and pain, in the case of dopamine these are probably better thought of as motivation and lethargy. There is another neuromodulatory system in the nervous system which does perfectly map onto the pleasure and pain dichotomy though, and that is the opioid system.
When someone takes an opioid drug, they press on the “pleasure” side of the scale, and the nervous system responds by downregulating its opioid receptors, which results in a paradoxical increase in pain over time as tolerance to the drug develops. Likewise, if someone were to stop taking that opioid for a number of weeks, the nervous system would eventually rebalance itself, slowly taking the extra weight off of the “pain” side. While this is taking place the person may undergo withdrawal as their body deals with the dysregulation of the opioid system. Within the neuroscience literature, the distinction between the dopamine and opioid systems are often referred to as the distinction between “wanting” and “liking,” which can be a useful shorthand.
The Interaction Between “Wanting” and “Liking”
Thus far we have described the experience of opioid use without reference to dopamine, and indeed, without reference to addiction either. Although it is painful to deal with withdrawal symptoms, if that were all someone had to contend with in order to overcome an opioid addiction, then many more people would be able to break out of the cycle for good. Things get more complicated when we consider the additional role that dopamine is playing. When someone in pain takes an opioid for the first time, they experience pain relief, or even a sense of euphoria above a baseline. The part of our brain which predicts the outcomes of our actions is surprised by this experience. It is “better-than-expected,” and this sense of “better-than-expected,” coupled with “do it again” is precisely what dopamine signals within the brain.
Dopamine enables the brain to reinforce the set of thoughts, emotions, and actions which lead to the “better-than-expected” outcome. In the case of the opioid user, what gets reinforced is taking the opioid and everything that led up to doing so. What happens as a result? The person who took the opioid now has to contend with the reality that they are both more likely to feel pain than they were before (due to the downregulation of their opioid receptors), and that they are more likely to reach for an opioid to treat their pain than they were before (due to the reinforcing effect of dopamine). This is a double whammy, and the crux of why treating addiction is so difficult.
Instead of a single mechanism, addiction involves contending with multiple overlapping brain systems which have been modified by the addiction. The first is responsible for the tolerance effects that people experience. The opioid system has become down-regulated such that it needs the exogenous opioid from the drug in order to function normally, otherwise the “pain” side of the see-saw is all that gets weighted. Abruptly removing the exogenous drug can be extremely difficult for a nervous system that has come to rely on it for normal function, and this is what is reflected in the withdrawal experience. The good news however is that in the absence of the drug the body’s natural homeostatic mechanisms will slowly work to up-regulate the opioid system again, until, after a few weeks, it works normally again.
The problem is that just doing this is not enough. There are also the effects of the dopamine to contend with, which have acted to sculpt the neural pathways in the brain in order to make it more likely that the person’s thoughts and actions will lead them to consuming the drug, even if their opioid system itself doesn’t need the drug anymore. These residual cravings and habits are often much more difficult to deal with, and some people struggle with them their entire lives after overcoming an acute addiction. Often, all it takes is a hint of a reinforced stimuli, such as an advertisement on TV for a pain medication, for a person to find themselves sucked back into the neural pathway that leads ultimately to relapse and drug use.
This is where high quality psychotherapy can be helpful. The hypothesis behind this approach is that the highly reinforced pathways have to be identified and weakened, while at the same time alternative competing pathways have to be strengthened to replace them. Psychedelic-assisted therapy may prove especially promising in this area, as it may make the neural pathways especially malleable for a short window of time in which they can be reshaped to help prevent relapse. Unfortunately, their malleability may also be itself a double-edged sword if not approached within a nuanced and therapeutic manner. With a skilled professional, it is possible to take advantage of the increased malleability from psychedelics to rework long-held mental habits that lead to drug use or other undesired addictive behaviors.
“Pressing on the Pain Side”
Much of the second half of Lembke’s book is devoted to a discussion of how to rebalance the scales of the pleasure/pain axis. One approach which she discusses in some detail is the concept of intentionally pressing on the pain side to help aid the process. She spends time talking about the popularity and health benefits of taking cold showers, and connects this to increases in dopamine release which take place during and after cold exposure. Another example is the runner’s high which people experience after intense cardio exercise. Although she highlights this approach as potentially beneficial, Lembke also brings up the fact that people can become addicted to taking cold showers or going on intense runs. Within the narrative of the book, she eventually arrives at an “abstinence is best” message.
In order to approach this in a more nuanced way, we can consider what goes on in the nervous system of someone with an apparent behavioral addiction to intense cardio exercise, such as a marathon runner. Unlike the opioid drug user, this person has not caused an over-weighting of the “pain” side of the see-saw. This is despite the fact that running releases opioids, and presumably that is why running was originally rewarding to begin with (the person felt “better-than-expected” after they would exercise). Instead the runner has carved deep neural pathways around all behaviors which lead to running, an effect which was mediated by dopamine release. It is possible that they have also downregulated dopamine in the process, requiring them to run everyday to sustain a sense of motivation, but this is likely independent of the original benefits they experienced from running. So it may indeed be compulsive, and may even be a problem, but it isn’t because they “pressed too hard on the pain side of the scale” per se.
We can also consider another example which Lembke herself brings up in the book. There is a drug called Naltrexone which acts as an opioid antagonist, meaning that it blocks the opioid receptors and prevents their activation. The drug was originally developed for the treatment of acute opioid addiction, since you can’t get the benefit of taking an opioid if it can’t make it to its target in your brain. What has been more recently discovered is that taking a daily small dose of naltrexone has the capacity to up-regulate the opioid system by taking just a little weight away from the “pleasure” side of the scale and forcing the nervous system to compensate by putting less of its own weight on the “pain” side. Importantly, there is no evidence that anyone has developed a naltrexone addiction, even though people report significant benefits to their wellbeing from taking the drug. This is because dopamine release is not involved, and thus the behavior of taking naltrexone is not reinforced.
The Good Life is About More Than Dopamine
Turning again to the title of the book, it is true that we now live in a world filled with “better-than-expected” experiences of all forms. We are constantly having our thoughts and actions sculpted by releases of dopamine which subtly rewire our neural circuitry. What we can lose sight of however is that there is a more primal reason why an experience is “good” or “bad” in the first place, and it often doesn’t directly have to do with dopamine. In this article I have been using examples of physical pleasure and pain, but as social animals, we also intrinsically value connectedness and bonding. We are often even willing to forgo personal pleasure in order to raise a family or maintain friendships, and we often experience these as kinds of pleasures that are deeper and more rewarding as a result. These social pleasures are in part mediated by endogenous opioids, oxytocin, and other non-dopamine neuromodulators.
Indeed, beyond the opioid system we discussed here, there are a number of other essential neuromodulators which are implicated in addictions of various kinds. One of the other primary ones is the GABA neuromodulatory system, which is involved in inhibiting activity in the brain. Returning to our see-saw metaphor, we could understand the GABA system as mediating the calm/anxiety axis. The class of drugs called benzodiazepines, which Xanax and Klonopin fall under, is often prescribed for anxiety disorders. Unfortunately, the GABA system is just as sensitive (if not more-so) than the opioid system to external stimulation, and can become easily downregulated, resulting in a difficult withdrawal experience if GABA-ergic drugs are not used carefully and sparingly. Serotonin is also essential to healthy brain function, but its effects are more complicated and don’t easily map onto a one-dimensional axis like the others we’ve discussed here.
In recent years I have come across popular discussions of dopamine and dopamine fasting most frequently in the context of social media and smartphone use. Social media notifications cause dopamine release in our brains not because they are rewarding in themselves, but because they signal social cues which are what we truly value at the most basic level. No amount of social media fasting or cold showers, regardless of how good they are for our dopamine systems, will help us with the more underlying problem of not having our more fundamental needs as humans met. I think that it is this unfortunate truth which is a little lost in Lembke’s book. We may be living in a “Dopamine Nation,” but if we are to become a happier and healthier society, we need to do much more than merely get our dopamine levels in check.
