TIME posted a very interesting article a few years ago
relating to a recent increase in media attention to addictions. You can find
the article here, and it is written by Maia Szalavitz. After hearing Dr.
McGehee speak about nicotine-related mechanisms behind addiction forming, I was
a little surprised at what I read in this article. By this, I mean I am surprised
by how much the author undermined neuroscience research for addiction
mechanisms.
Before we dive down and examine this article, it is
important to keep two things in mind. First, this article was written in 2011.
Although this time is still contemporary, less research about addiction was
available to the author. Next, this article was written during a craze where “media
headlines scream daily about new neuroscience findings…” on addictions. Some
opinions could be exaggerated or biased towards whatever the mass’s opinion was
(thank you, de Tocqueville).
This article starts off by claiming that “addictions hijack
the brain’s pleasure systems” is circular reasoning and confuses the real
purpose of the brain’s pleasure pathways. Szalavitz reasons that brain pathways
are intended to make evolutionary activities (i.e., sex and eating) fun and
enjoyable. Continuing, she states that drugs cannot be said to hijack the
reward system to create addiction because that would also be to say that
healthy urges like eating and sex would not cause addiction. To conclude her
point, Szalavitz says sex and eating can become addictions by activating brain
regions that generate pleasure from drugs, and that is why hijacking is not the
appropriate description.
To be honest, Szalavitz’s logic can be pretty confusing. I
almost agreed with her when it was stated that activities and substances cannot
“hijack” a reward system because the system is meant to get us to pursue food
and sex relentlessly. This made me think about what Dr. McGehee stated in his
nicotine addiction findings. He stated during his presentation that the amount
of cigarette packs a human smokes will plateau after 2-3 packs per day. The
body can form needs and desires for a drug, but with some substances the body
can also say “enough is enough.” I believe the same idea works for food too. I
cannot pursue Chipotle endlessly. I will undoubtedly become sick of it after
1.5-2.0 burritos and not want to see food for a good half day. I believe
Szalavitz needs to be more careful with saying that we endlessly pursue sex and
food. A tribal and sensory-driven view of humanity undermines our agency and
ability to reject certain sensations.
Lastly, Szalavitz states that “no study has ever isolated a
simple brain change that is always seen in addicts and never in non-addicts.
And although some studies have found changes that can predict an addict’s odds
of relapse, they’re not always accurate.” I would like to note here how the
first sentence in Dr. McGehee’s paper, from 2011, titled “Nicotine Potentiation
of Excitatory Inputs to Ventral Tegmental Area Dopamine Neurons” began. It states,
“Drug-induced changes in synaptic strength are hypothesized to contribute to
appetitive behavior and addiction.” This shows first that Szalavitz may not
have been quite up to date with neuroscience literature before writing this article.
Secondly, Szalavitz assumes that addiction is a black-and-white mechanistic
process. Continuing with Dr. McGehee’s study, there are varying levels of
smokers. Accordingly, the long-term potentiation in Ventral Tegmental Area
dopamine neurons may also vary with the level of addiction (i.e., a process
hypothesized to underlie nicotine addiction can vary with level of addiction).
Assuming that a process will either be present or absent depending on addiction
undermines the complexity of understanding addiction circuits.
To conclude, it is always important to read news articles
with a critical eye. In this case, hearing that no study has been conducted to
isolate a simple change in addict’s or non-addict’s brains is true, but very
misleading. The fact of the matter is that addiction is much more complex than
one change. Understanding the summation of many changes in neural networks will
ultimately be a key to understanding addiction and to help us better treat it.
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