Neuroscience of Anxiety
Humans can't survive without anxiety... but it's fair to say that living with it is no walk in the park.
Whether it's a sudden feeling of unease, fear, impending doom, or a lingering sense of worry or dread that never seems to go away, we need anxiety even if we'd much rather live without it.
So how do we live with it?
How do we understand it so we can regain control when our bodies' alarm tells us there's something to fear?
And how do we keep hold of our anxieties and prevent them from developing into something more serious?
In this month's deep-dive episode, Laine walks us through some of the science behind the second-most common mental illness that humans experience. Using findings from scientists LeDoux, Pine, Nesse, Caouette, Guyer, and McNally, we discuss things like:
what parts of the brain are involved when we feel anxious (and why its similarity to depression is important)
how to recognize anxious behavior in ourselves and others
and what we can do to offer support and keep anxiety at bay (since we can't ever get rid of it completely)
For more resources on anxiety, head to the episode on our website www.brainblownpodcast.com. If you have any topics you'd be interested in learning more about, please feel free to send us an email at info@brainblownpodcast.com!
We'd love to hear from you.
TIMESTAMPS
1:05 - intro
8:20 - Caveman Jo
10:48 - Why Neuroscience?
13:52 - Break
14:07 - The Brain
23:46 - New "Neighbors" Involved
28:41 - Break
28:53 - The Body
37:09 - The Behavior
39:31 - Break
39:47 - Takeaways
RESOURCES
Joseph E. LeDoux, Ph.D., Daniel S. Pine, M.D. - Using Neuroscience to Help Understand Fear and Anxiety: A Two-System Framework
Randolph Nesse - "Proximate and evolutionary studies of anxiety, stress and depression: synergy at the interface"
Justin D. Caouette, Amanda E. Guyer - "Gaining insight into adolescent vulnerability for social anxiety from developmental cognitive neuroscience"
Richard J. McNally - "Mechanisms of exposure therapy: How neuroscience can improve psychological treatments for anxiety disorders"
General Outline of Episode
We talked about the #1 most common mental illness, so it’s only fitting that for our second full episode, we talk about the 2nd most common mental illness - anxiety.
Just like last time -
We’ll stick to the more colloquial (ordinary, more common) experience
Mention the clinical (when you are an anxious person vs. when you have a disorder that needs more support than anything you can do for yourself or learn on the internet)
Let’s start there
This is the neuroscience of anxiety.
LAINE
Randolph Nesse “The extraordinary efforts we humans have made to understand anxiety disorders and depression are entirely understandable. After all, the related states of fear and sadness are two of the most common and severe kinds of human suffering. They are, like pain, aversive in their very essence. To one degree or another, we all experience them and they are thus very different from diseases like cancer or stroke, which only affect some people.”
Anxiety is the most common mental illness 31.1% of Us adults have experienced an anxiety disorder in their lifetime - higher in women and higher in adolescence (nami) - COVID has triggered a 25% increase in anxiety (who)
Anxiety (colloquially) - Synonyms - Fear, unease, Apprehension, concern, doubt, dread, misery, agitation, panic, worry, concern, alarm
Anxiety (clinically) - Generalized anxiety disorder - excessive worry more days than not for at least 6 months about a variety of things - difficult to control and comes with other symptomology (difficulty concentrating, irritability, tension, restlessness, etc)
Anxiety - all things are anxiety lol - could instead have trauma - important to know that anxiety is stress and stress is toxic - leads to heart disease, digestional disease, diabetes, cancer, etc
PART 1: Terms & Background Info (5-10 minutes)
Define key terms.
Worry vs anxiety
^^clinical vs. colloquial (when you are an anxious person vs. when you have a disorder that needs more support than anything you can do for yourself or learn on the internet)
Any interesting history on how this topic came about or when we “discovered” it?
Caveman Jo - how did they deal with it?
Marc- Antonie Crocq's “A history of anxiety: from Hippocrates to DSM states “
“In the Tusculan Disputations (TD), Cicero (106 BC to 43 BC) wrote that affliction (molestia), worry (sollicitudo), and anxiety (angor) are called disorders (aegritudo), on account of the analogy between a troubled mind and a diseased body……in it is a plea for Stoicism, a branch of philosophy that is one of the pillars of today's cognitive therapy.” This book argues for us to work for peace of mind. To quote Seneca, “fear of death is the main cognition preventing us from enjoying a carefree life (DTA, chapter 11. “He who fears death will never act as becomes a living man”). This book argues that reducing anxiety is focusing the mind on the present, or practicing mindfulness.
Defined as the anticipation of future threat; it is distinguished from fear (peur; Furcht), the emotional response to real or perceived imminent threat.”
Anxiety is tricky - it’s normal
Technically promotes survival so we need it for evolution
20th century - disorder - seen as recent.
Hippocrates wrote of phobias
PART 2: What About Neuroscience (5 minutes)
Why are we looking at THIS TOPIC through this lens?
What unique perspective will Neuroscience show us regarding this topic?
LeDoux and Pine argue “Recent events in psychiatry highlight a growing chasm between
basic science and the clinic (1). Progress in understanding the brain has not been mirrored in improved clinical outcomes. Most current therapies with some efficacy emerged decades ago. Promising new treatments either have not turned out to be useful when tested with patients or exhibit potential adverse effects that limit their applicability to severe, treatment-refractory disorders.”
**BREAK**
PART 3: The Science (30-35 minutes)
Brain
CHERYS
Review the 3 siblings:
Old brain - first to develop, keeps your brain and body running (breathing, heart beating, etc)
Midbrain - loud, tantrum thrower, the job is to keep you safe (but isn’t often wise about it)
Young brain (PFC) - last to develop, what makes humans human, realistic, understanding, chills us out, explains things (in this podcast we’re hanging out in the PFC, trying to understand things in a new way!)
Anxiety is… midbrain?
Midbrain
Amygdala
Sometimes I feel like when anything is going wrong in the brain, it’s probably the amygdala’s fault. With this, it’s hypothesized that your amygdala, or your brain’s alarm, is going off much more often, causing such a high amount of fear that we see avoidance and that ‘shutting down’.
LeDoux and Pine argue that we often discuss fear = amygdala and your limbic area. They argue this is more about “immediately present threat activates the lateral nucleus of the amygdala, which by way of connections to the central nucleus of the amygdala initiates the expression of defensive behavioral reactions” so this part of your brain says something is wrong and responds. Sometimes that response activiates “connections from the lateral amygdala to the basal amygdala, and from there to the nucleus accumbens” and this causes avoidance as a defensive action.
HPA Axis - Your hypothalamus and its friends the anterior pituitary gland, and adrenal gland.
Your hypothalamus sits in the same area of the amygdala and your hippocampus and it has your anterior pituitary gland and adrenal gland on speed dial. This can also damage this HPA axis permanently. This also causes issues between the PFC and your amygdala.
Favaelli, Sauro, Lelli et all argue that stressful life events, specifically in childhood, cause a dysfunctional HPA axis which increases the likelihood of all anxiety disorders.
Remember from depression we say stressful or traumatic life events, and that is causing the damage to your HPA, which of course puts other parts of your brain out of wack. “For example, there was a study done by Heim and Nemeroof of women who had been sexually abused or assaulted as children having significant ACTH Adrenocorticotropic Hormone secretion and heart rate with large increases in cortisol, even without an active stress item occurring. “
Hippocampus -
I have been calling this your brain's filing cabinet for a while, specifically storing memories of episodic (that one thing that happened that one time), knowledge of where things are, how my memories work in relation, etc. It hangs out near your amygdala. High levels of activation in the amygdala cause our hippocampus to not work properly - both in recording and retrieving - this is really seen in trauma so we will cover more on that later in this season.
Favavelli, Lo Sauro, Lelli et all “In acute anxiety, the activation of the HPA axis is adaptive since cortisol seems to reduce perceived fear by impairing the memory retrieval of emotionally arousing information. This is literally saying your amygdala is activating your HPA axis -causing your hippocampus to not work properly!
For our brain to work properly we need to have a stressor that causes us to cope with stress healthily - no for real if I don’t do the thing bad things happen - but if this fails the HPA axis doesn’t stop being activated - continuing to release cortical, decreasing your serotonin inhibitors and causing wear and tear on your body.
DLPFC
DLPFC can help calm down your amygdala - in this case, it is clearly not. Nothing is telling your brain to chill.
New parts of the brain:
BNST - Basomedial Forebrain - Fingertips - Prefrontal cortex that is wrapping around your midbrain -
LeDoux and Pine “bed nucleus of the stria terminalis (BNST) is engaged when threats are uncertain resulting in behavioral inhibition and risk assessment (40)
We have brain imagery of both humans with and without anxiety disorder and what we see is a difference in BNST to process uncertainty.
Medial PFC - right in front of BNST
Dolan and Murry PFC (which is right on top of your MPFC - this is what we covered in depression which is attention control and related processing - Your MPFC is controlling flexible and adaptive motivational response, such as the acquisition of fearful responding, fear extinction, as well as approach and reward-driven behaviors”
A major job is to regulate that amygdala - to calm down - that is weakened.
Let’s talk about Neurotransmitters
So what is Serotonin- rewards, remembering, learning, feeling and thinking
Norepinephrine - movement or frozen
Dopamine for ways to make you smile, sleep, and have sex
What have have seen according to Bar is that we do see that this is a great thing to help decrease the atrophying of the hippocampus. This is new research, a little controversial but exciting. There is some argument that your SSRIs need to generate new neurons in this area to successfully treat depression. Some people don’t respond to SSRIs as much, specifically, if we see less activation in the right prefrontal regions and right posterior regions according to Davidson and Heller and Nitscheke, so with more anxious arousal we see less improvement.
A new change to medication with anxiety using less SSRIs and starting to look at medications that are originally for things like high blood pressure - because if we can get your body to calm - perhaps we can get your brain to calm
Why anxiety and not depression?
Body
One of the clearest warning signs of feeling anxious is what’s happening in our body, so let’s highlight some of those things!
If we go back to Season 1, Episode 4 in the Neuroscience of Safety - looking at our vagus nerve - Porages argues that depression is a reaction of dorsal vagal (collapse/alone/dispair) and sympathetic is fight-flight/angry anxious - protection - activated
Body for anxiety is a key area - it is where your body becomes activated when you have to run or fight - this is largely
breath (will change from high in your chest and fast which is good for running - lots of air quickly - or low and deep - good for relaxation
Muscles - tense and activated - need to move and move quickly
Stomach - activated or calm - a little anxiety will make you go to the bathroom now (before the bad thing shows up or too long and no activation because you’ll die if you are running from a bear and you have to poop)
Heart - fast and hard - activating blood to your muscles to get them what they need to respond or slow and calm if you are relaxing
We want to learn WHY we do what we do as humans, and we’ve looked to the brain for explanations…
**BREAK**
PART 4: TAKEAWAYS (10-15 minutes)
Does this serve you?
Your brain is often ‘too helpful’ - this is a key place
Body regulation is one of the biggest things
CBT - can’t do this if you are not regulated
Be present in your body - be present in the moment - help support your MPFC (food might be important here)
LEARN WHEN YOU ARE ANXIOUS - you can’t do anything if you don’t know
