Mindfulness & Anxiety
When writing this article, I was faced with a decision…
Write a surface level post about mindfulness & anxiety complete with 50 references to the “present moment”, “oneness”, inordinate use of the word “space”, and a laundry list of benefits that you’ve undoubtedly heard before…
Provide a detailed answer to the question you have right now, in the form of a comprehensive explanation of the science behind mindfulness & meditation, and efficacy in treating anxiety.
I chose the latter for two reasons:
- I believe that understanding the biological mechanisms of mindfulness & meditation will provide more motivation for you to develop your own effective practice (and help others to do the same)
- I am a nerd
SO, for those of you who are itching for a detailed scientific answer to the question posed below, give those suspenders a snap and let’s get to it…
How does mindfulness reduce anxiety?
Mindfulness meditation reduces anxiety in two major ways: Firstly, singularly focusing our attention limits activity in the brain’s neural network (Default Mode Network) which we utilize to negatively ruminate about the past or worry about the future. Second, the act of breathing in a slow focused manner reduces activity in the fight or flight branch of our autonomic nervous system (sympathetic nervous system), stimulates the branch of our autonomic nervous system responsible for rest & digest functions (parasympathetic nervous system), increases heart rate variability (HRV) & signals safety to our survival brain (i.e. the amygdala, hippocampus & hypothalamus, etc.)
Now, let’s unpack that last paragraph for those of us that are unfamiliar with the “attention networks” & the nervous system.
Mindfulness Helps Us Stop Ruminating
To understand why focusing on the “present moment” reduces negative thoughts, we first need to understand the function & purpose of two of the human brain’s attentional networks the Default Mode Network (DMN) & the Task Positive Network (TPN).
Function & purpose of the DMN & TPN:
- The Default Mode Network is a large network of correlated brain regions which are utilized when we are not focused on the outside world but are instead using our imagination or daydreaming. It is also the part of the brain we use to venture into our past, self-reflect or to project ourselves into the future
- The Task Positive Network is a large network of correlated brain regions we use when performing attention-demanding tasks or successfully focusing our attention on a specific action or stimulus
A very important note about these two neural networks is that they are mutually exclusive – albeit not entirely. Meaning the activation of the DMN reduces the activity of the TPN and vice versa.
This is why free solo rock climbers (who climb with ropes) aren’t paralyzed by the fear of falling off the cliff they are clinging to with their pinky fingers: they are masters of their attention networks. While climbing, they are hyper focused (TPN) on each move which blocks the ability to think about falling (DMN). They might peer up for a moment to imagine their next few moves (DMN), but then they go right back to the chalk bag and reach for the next hand hold with laser focus (TPN).
So, while DMN centric mind-wandering enables us to learn from our past & plan for the future, it’s also what enables us to ruminate, worry & stress ourselves out for both legitimate & illegitimate reasons.
This negative use of our imagination has been referred to as guilty dysphoric daydreaming. Unfortunately, the increased digital stimulation, social interactions & pace of modern life serves to program our brain & nervous system with a bias for this unproductive use case of the imagination. This is why, when we aren’t taking action or focusing on anything (like our phones or Netflix), we often find our mind drifting into the stress-producing currents of past & future thought, rather than daydreaming in a positive constructive manner.
(If you’ve ever been lying in bed late at night and suddenly thought about that thing you did in 7th grade, subsequently, forcing yourself to revitalize that feeling of embarrassment all over again, then you know what I mean…)
How do we stop ruminating then?
Simple… We activate our Task Positive Network!
And how might we activate the TPN?
Simple… By focusing our attention on a specific action or sensation. Like climbing a rock!
Or taking a slow, focused & deliberate breath…
So, during mindfulness meditation, we might singularly place our focus on the rhythm of the breath or on the feeling of our feet planted firmly on the earth. This focused attention activates our TPN, subsequently, reducing activity in the DMN, and our brain’s capacity to engage in anxiety-inducing thinking is greatly diminished.
(That is, as long as you stay focused…)
Mindful Breathing Affects Our Nervous System
The second reason mindfulness reduces anxiety has less to do with mindfulness, specifically, and more to do with how certain breathing techniques (found in many sorts of meditation) affect our brain & body.
But, when utilizing mindfulness meditation is to reduce anxiety, not all breathing exercises are created equal. Slow, focused breathing (NOT deep breathing) is what we need to figuratively “calm our nerves.”
To understand why, we’ll need to take a brief detour, use our DMN to rehash our traumatic memories of high school biology class & revisit a little more about human physiology, and more specifically, the autonomic nervous system.
The Autonomic Nervous System (ANS) is our body’s automatic control mechanism for a wide variety of bodily functions. It regulates our heart rate, digestion, respiratory rate (when we aren’t actively controlling it), pupillary dilation, urination & sexual arousal. It’s also the system we rely upon to activate – or deactivate – our fight, flight, freeze or shut down response.
The ANS acts – and thankfully so – almost entirely unconsciously, meaning we don’t have the conscious ability to tell it how to do its job.
This is great news for those of us who like to sleep soundly through the night – without having to get up to breathe.
However, if you are anything like me (who never sleeps) and typically catalog all your anxiety-producing thoughts at 3 AM, instead of resting comfortably, then part of the problem might actually be rooted in an imbalance between the two main branches of the autonomic nervous system:
- The Sympathetic Nervous System (SNS): the branch of the ANS responsible for controlling our fight, flight, freeze or shut down responses.
- The Parasympathetic Nervous System (PSNS): the branch of the ANS responsible for controlling our rest & digest functions.
Modern life, though undeniably safer than its prehistoric predecessor, is actually fraught with far more triggers of our survival brain & fight or flight systems. The result can be an overactivation of the SNS, leading to a general, prolonged existence in a state of SNS dominance.
Symptoms of SNS Dominance include digestive problems, nail-biting, elevated heart rate, over-reactivity, poor sleep & other troublesome manifestations of stress which take a serious toll on your body over time.
In order to fix this problem & reduce our anxiety, we need to activate our parasympathetic nervous system, because like the DMN & TPN, the SNS & PSNS – excuse the vast quantity of acronyms – are also mutually semi-exclusionary. Meaning, when we turn down the volume on our stress response systems, our PSNS can begin to stimulate our healing rest & digest functions – then, me & my fellow nail biters can allow our nails to grow back to a more reasonable length.
While I did say that the autonomic nervous system acts almost entirely unconsciously, there is one important exception to the rule, both warranting the “almost” & enabling us to consciously reduce the activation of our fight or flight response.
Yep, you guessed it, it’s the breath!
The breath is the only conscious mechanism we have for controlling our ANS, because both our sympathetic & parasympathetic nervous systems have a hand in affecting our respiratory rate.
Specifically, inhalations activate – or can be activated by – the SNS, while exhalations activate – or can be activated by – the PSNS. This is why when someone jumps out & scares you, you gasp instead of sighing.
It’s also why when you feel relaxed, you sigh instead of gasping.
Therefore, it’s long, slow & easy exhalations that equate to increased activation of the parasympathetic nervous system & decreased activation of the SNS, not deep inhalations. In fact, deep breathing can inadvertently cause anxiety because of the emphasis on inhalations, which, as we now know, stimulates our sympathetic nervous system.
How Our Breath Affects Our Brain
OK, so we’ve covered a lot, but to put a bow on this thing, we need to talk about why activating the parasympathetic nervous system actually reduces anxious thinking, worrying & needless stress in the brain.
(You can do this! Just one word at a time…)
Essentially, by consciously upregulating our PSNS with the breath, we also affect another powerful organ that is controlled by both the SNS & PSNS… the heart!
When we inhale, our SNS is activated, increasing our heart rate. When we exhale, our PSNS is activated, decreasing our heart rate.
Breathing in a slow, controlled & focused manner increases the rate at which our heart rate changes as we oscillate between inhalation & exhalation, which is another way of saying it increases our heart rate variability (HRV).
(For my biophysicists, HRV can be measured by taking the RMS of the all the successive differences in RR intervals over a given period of time – though, I suppose you already knew that.)
Increasing our HRV, or how responsive our heart is to the oscillations between sympathetic & parasympathetic nervous system stimulation, may sound inconsequential, but it most certainly is not. This is because the heart is far more than a pump; it’s an intelligent organ that both receives & transmits information throughout the body.
In fact, the heart has its own intrinsic nervous system comprised of over 40,000 neurons – about the same amount of neurons found in a sea slug – which enable it to learn, store information & make decisions independent of the head brain!
The electrical signals produced by the heart are so powerful, in fact, that they affect the function of our brain.
Specifically, the electrical signals from coherent heart rhythms (e.g. high HRV rhythms) synchronize with the cells in the amygdala, the fear center of the brain, communicating to it that we are safe. When the amygdala receives this signal, it tells the hypothalamus (the control switch for our autonomic nervous system) to suppress activity in our SNS & adrenal cortical system and allow the rest & digest functions of the parasympathetic nervous system to take center stage.
Additionally, as the amygdala calms down, blood flow to the prefrontal cortex (responsible for higher cognitive functions like reason) increases. This enables us to provide a rational counterargument to the thoughts causing our anxiety. This logical reasoning is then cross-referenced with information stored in the hippocampus (our gateway to strong, traumatic, survival based memories) to contextualize our anxious thinking, and determine whether we should actually freak out or not.
Together, our hippocampus & prefrontal cortex can provide logical, electrochemical reassurance to the amygdala that no clear & present danger exists, further reducing its effect on our brain and nervous system.
(Regaining access to our prefrontal cortex can take over 20 minutes after high stress stimulus, and is the reason we often don’t think of the perfect words to win an argument until quite some time after we’ve lost it.)
Meditation Balances Hormones
Now, I know I might have under sold the depth we were going to go into, but I want you to really be able to impress your friends at your next cocktail party debate over the efficacy of mindfulness (which I pray you never have). Therefore, we need to answer the last question which you are indubitably asking at this very moment:
“How EXACTLY does the hypothalamus, sympathetic nervous system, adrenal cortical system & parasympathetic nervous system act to reduce anxiety during mindfulness meditation?”
Well, I’m so glad you asked!
These systems reduce anxiety by balancing the brain and body’s hormones & neurotransmitters. Particularly, by reducing stress hormones/neurotransmitters while increasing the production and release of rest & digest hormones/neurotransmitters.
You see, during high levels of stress or anxiety, the hypothalamus tells the SNS & pituitary gland to activate the adrenal cortical system.
The adrenal glands & medulla respond by releasing over 30 different hormones & neurotransmitters into the bloodstream, including:
- Cortisol (hormone)
Symptomes of chronically high levels of corisol include: increased blood pressure & glucose (sugar) levels, mood swings, weight gain in the face, chest & abdomen, disruption of menstrual cycles & decreased sex drive for women, and anxiety & depression, to name a few
- Epinephrine & Norepinephrine (neurotransmitters that double as hormones)
Responsible for increasing the heart rate, heart contractility (how hard the heart squeezes), blood sugar levels, constricting blood vessels (this is what’s responsible for that chill you get when afraid) & the world famous “adrenaline rush”
Conversely, during mindfulness meditation, the hypothalamus (when it’s being nice), pituitary gland & PSNS cause the release of the “good guys & girls” of the hormone/neurotransmitter world, including:
- Acetylcholine (neurotransmitter)
Release of this neurotransmitter results in: decreased heart rate, relaxed skeletal muscles, contraction of smooth muscle tissue (important for digestion), dilation of blood vessels, increased motivation & sexual arousal, improved memory formation, attention & learning, and promotion of REM sleep
- Oxytocin (hormone)
Release of this hormone helps balance sex hormones in both men & women and improves bonding during social interactions
- Prolactin (hormone)
Improves immune system function, reproductive health, and as the name suggests, milk production in women.
- Vasopressin (hormone)
Balances concentrations of glucose (sugar) & salts in cells, and consequently, water concentrations in fluid space between the cells
- DHEA (hormone)
Counteracts the effects of cortisol, acts as a precursor chemical for the production of testosterone & estrogen, and is associated with increased longevity & “anti-aging” (whatever that means). Studies have shown that those who practice meditation have 43% more DHEA than their counterparts.
- Somatotropin (growth hormone)
Improves sleep, recovery, glucose levels in the blood & reduces stress
Downstream effects caused by these hormones during meditation include:
- Increased serotonin (neurotransmitter)
Improves mood, happiness, and cognitive function, while reducing anxiety
- Increased GABA (neurotransmitter)
Decreases anxiety, depression & insomnia. A study at Boston University School of Medicine found that one hour of meditation or mindfulness can boost GABA levels by 27%
- Increased melatonin (neurotransmitter)
Improves sleep, immune function, & resistance to cancer. Research at Rutgers University found that those who meditate regularly have an average of 98% more melatonin than people who do not
So, you can do the math…
Add all these positive benefits of mindfulness & meditation, from the attention networks to the nervous system to the heart to hormone & neurotransmitter regulation, and you can see that the answer to the question posed at the beginning of this article has quite a few answers.
The fact is, there is a multitude of ways a simple mindfulness practice reduces anxiety, and a real answer requires an explanation of the science which undergirds the true, but often nebulous, claims made by your neighborhood yoga teacher.
Now, you may have to read this article a few times to let all this information soak in, however, I will part with a better suggestion. (You’ve done enough stamp collecting for one day ;))
Whether you meditate or not, take this information to heart and realize its importance. All these numbers & names are nothing more than proof of the value to your health and well-being of a daily practice of focused meditative contemplation.
Just a few minutes a day will yield significant benefits over time, but the key is consistency.