The Upward Spiral: Using Neuroscience to Reverse the Course of Depression, One Small Change at a Time

by Alex Korb

We now know that what you do with your mind—how you focus your attention, intentionally shape your thoughts, and purposefully calm your emotions—can directly change your brain. That’s the key to neuroplasticity

Just fifteen minutes of biking is sufficient to increase activity in circuits responsible for emotional control and to raise levels of the neurotransmitter serotonin.2

Neuroscience is the study of the brain, including the biological basis behind our thoughts, feelings, and actions. Research

Essentially, your brain is full of intricate, interacting neural circuits. There’s a worrying circuit and a habit circuit. There’s a decision-making circuit and a pain circuit. There are circuits for sleep, memory, mood, planning, enjoyment, and more, and they all communicate with each other. We’ve

Depression Is a Downward Spiral We all know what it means to be stuck in a downward spiral. Maybe one Friday night you’re invited to a party, but you have a brief thought like I don’t think it’ll be that fun, so you don’t go. Instead, you stay up too late on the couch watching television. The next day you sleep in and don’t have much energy. No one calls you, so you feel even more isolated, and now you’re even less likely to be social. Nothing seems particularly interesting, so you just lie around all weekend. Pretty soon you’re unhappy and alone, and you don’t know what you can do about it, because every decision feels wrong. This is the edge of what it means to be depressed.

Downward spirals occur because the events that happen to you and the decisions you make change your brain activity. If your brain activity changes for the worse, it contributes to everything snowballing out of control, which further exacerbates your negative brain changes, and so on. Fortunately,

In fact, people with depression do not necessarily feel sad—they often feel numb, like an emptiness where emotion should be. Hopeless and helpless.

hard to fall asleep and to stay asleep. Aches and pains are felt more deeply. It’s hard to concentrate, and you feel anxious, ashamed, and alone.

Exercise would help, but you don’t feel like exercising. Getting a good night’s sleep would help, but you’ve got insomnia. Doing something fun with friends would help, but nothing seems fun, and you don’t feel like bothering people.

Depression is caused by the tuning of various brain circuits and their interactions with the world and with each other. Think

Two parts of the brain in particular are to blame: the prefrontal cortex and the limbic system. To simplify, the prefrontal cortex is basically the thinking part of the brain, and the limbic system is the feeling part. In depression, something is off with the way these regions act and communicate with each other.

You can’t always change where you are, but you can change where you’re going.

What if you suddenly had more energy, slept better, hung out with your friends more, felt happier? Your neural circuits have just as much potential for this as they do for depression. It often takes only a few positive emotions to kick-start the process, which then begins to fuel positive changes in other areas of your life—this is the upward spiral, and its incredible efficacy has been proven time and again, in hundreds of scientific studies.4

It turns out that positive life changes actually cause positive neural changes—in the brain’s electrical activity, its chemical composition, even its ability to produce new neurons.

For example, exercise changes the electrical activity in your brain during sleep, which then reduces anxiety, improves mood, and gives you more energy to exercise. Similarly, expressing gratitude activates serotonin production, which improves your mood and allows you to overcome bad habits, giving you more to be grateful for.

Aside from understanding and acceptance, there are eight powerful life changes that contribute to the solution, and a chapter is devoted to each: exercise (chapter 5), decision making (chapter 6), sleep (chapter 7), habits (chapter 8), biofeedback (chapter 9), gratitude (chapter 10), social support (chapter 11), and professional help (chapter 12).

If you happen to be depressed and you’re healthy enough to read this book, then you have what it takes to rewire your brain and reverse the course of depression. We’ve all got the same brain circuits, so whether you’re depressed or anxious or out of sorts or doing just fine, you can use the same neuroscience to improve your life.

And sometimes tweaking the tuning of one brain circuit can start to reverse the course of depression.

Neurotransmitters transmit information by floating into the space between neurons—the synapse—and binding to the next neuron.

Everyone votes on who the president should be, and depending on those votes, the country veers off in one direction or another. If you can change the number of votes in a few key swing states by only a few percentage points, you can dramatically change the course of the country. The same is true of the brain. By changing the firing rate of neurons in a few key regions, you can influence the pattern of activity in the entire brain.

various circuits influence each other. If you’re feeling depressed or happy or hungry or horny, it’s the result of the way a whole bunch of circuits are impacting each other.

For example, the serotonin system is all the neurons that release or react to serotonin (just as the Delta “system” would be all the cities Delta connects to).

In the 1960s, depression was thought to be a matter of having too little of the neurotransmitter norepinephrine. Then, a few years later, the theory changed to a deficiency of serotonin. We now know it’s much more complicated. Sure serotonin and norepinephrine are involved, but so are dopamine and numerous other neurochemicals.

You don’t need to remember it all now, just know that each neurotransmitter system has a few primary effects: Serotonin—improves willpower, motivation, and mood Norepinephrine—enhances thinking, focus, and dealing with stress Dopamine—increases enjoyment and is necessary for changing bad habits

Oxytocin—promotes feelings of trust, love, and connection, and reduces anxiety GABA—increases feelings of relaxation and reduces anxiety Melatonin—enhances the quality of sleep Endorphins—provide pain relief and feelings of elation Endocannabinoids—improve your appetite and increase feelings of peacefulness and well-being

Go out in the sunlight. Bright sunlight helps boost the production of serotonin. It also improves the release of melatonin, which helps you get a better night’s sleep (chapter 7). So if you’re stuck inside, make an effort to go outside for at least a few minutes in the middle of the day. Go for a walk, listen to some music, or just soak in the sun.

This is an oversimplification, but in general, each neurotransmitter contributes to a different depressive symptom. A dysfunctional serotonin system is responsible for the lack of willpower and motivation.

Unfortunately, depression is not just a matter of not having enough norepinephrine, serotonin, and dopamine, and thus it’s not solved by simply increasing the levels of these neurotransmitters. But that is part of the solution.

Changing any one of these factors can increase serotonin activity. For example, most antidepressant medications work by blocking serotonin-sucking proteins (known as serotonin transporters), thereby increasing the amount of serotonin that can act on receptors.

As I mentioned in the introduction, depression is primarily a result of poor communication between the thinking prefrontal cortex and the emotional limbic system.

The fronto-limbic system regulates your emotional state, and when not functioning, it well can push you into depression.

The prefrontal cortex gets its name from the fact that it is the front-most part of your brain. Basically, it is the whole surface of the front third of your brain, sitting just behind your forehead. It is the CEO of the brain—the

Our big prefrontal cortex gives us a huge evolutionary advantage, but it can also cause problems. In depression, it is responsible for worrying, guilt, shame, problems with thinking clearly, and indecisiveness.

Pretty much the whole prefrontal cortex is affected by depression.3 Not feeling any motivation? It’s likely the fault of reduced serotonin in the ventromedial prefrontal cortex. Finding it difficult to make plans or think clearly? It’s probably disrupted activity in your dorsolateral prefrontal cortex.

In contrast to the highly evolved prefrontal cortex, the limbic system is an ancient collection of structures located much deeper in the brain (even early mammals one hundred million years ago had limbic systems). The limbic system is the emotional part of the brain and is responsible for things like excitement, fear, anxiety, memory, and desire. It is primarily composed of four regions: the hypothalamus, the amygdala, the hippocampus, and the cingulate cortex. The hypothalamus controls stress. The amygdala is the key to reducing anxiety, fear, and other negative emotions.

Feeling tense? On edge? Elevated stress is both a cause and a symptom of depression, and it can be attributed to the hypothalamus in the central limbic region.

Finding ways to calm the hypothalamus is therefore one of the best ways to reduce stress.

As a kid, I never would have said I had anxiety; I just got lots of stomachaches when I had to take tests or while waiting in line for scary roller coasters. But lo and behold, as I grew into a calmer adult, my stomachaches went away. Anxiety isn’t always obvious, but increased anxiety, in one form or another, is a symptom of depression.

People with depression often have higher amygdala reactivity, so reducing that can help lower anxiety and relieve depression.4

When was the last time you were truly happy? People with depression often have trouble remembering happier times but have no problem recalling sad events. This memory bias can be blamed on the hippocampus, which sits deep in the brain, adjacent to the amygdala; it also has strong connections to the hypothalamus.

That’s somewhat problematic in depression, because the new memories your hippocampus forms will skew to the negative. However, the hippocampus does much more. It is also central to context-dependent memory, which is the fact that it’s easier to remember things that relate closely to your current situation.

Unfortunately, in depression, there is a large downside to context-dependent memory. Because the “context” is depression, all those happy memories that are easy to recall when you’re in a good mood suddenly evaporate. Meanwhile, all the tragedies in your life become too easy to remember.

The small hippocampus is likely the result of chronic stress, which can damage and kill neurons. Depression is stressful and thus disrupts the proper functioning of the hippocampus. Fortunately, it’s possible to grow new neurons in the hippocampus, and we’ll cover that later in the book.

Difficulty concentrating is another symptom of depression, as is a greater focus on the negative,

The anterior cingulate notices all your mistakes, plays a central role in the pain circuit, and contributes to the tendency to dwell on everything that’s going wrong.7

Think of happy memories. Happy memories boost serotonin in the anterior cingulate (chapter 8). Try to think of one happy memory before you go to sleep—write it in a journal or just reflect on it.

Interestingly, the neurotransmitter serotonin is highly concentrated in the anterior cingulate. That’s important for depression, because serotonin is the neurotransmitter system most commonly targeted by antidepressant medications. In fact, activity in anterior cingulate can predict who will get better on antidepressant medication and who won’t (shout-out to my dissertation).8 In addition, directly stimulating the anterior cingulate with electrodes can vastly improve depressive symptoms.

Depression is often accompanied by bad habits such as impulsiveness, poor coping skills, addiction, and procrastination.

Because your habits are behaviors you do automatically, without thinking, once you create a good habit it has the power to change your life without conscious thought. In depression, reduced dopamine activity in the dorsal striatum is primarily responsible for feelings of fatigue.

Dopamine is released in the nucleus accumbens whenever you do anything fun and exciting—or at least it’s supposed to. In depression, reduced dopamine activity in the nucleus accumbens explains why nothing seems enjoyable.