Anxiety vs. Stress: What's The Difference?

We all experience stress, right? It's a fact of nature, and it offers pretty important evolutionary advantages. Without it, we wouldn't be able to sound the proverbial alarm if danger were imminent. Stress is one of the greatest tools an animal has to beat the odds and stay alive.

Human beings are animals, yes, but we contend with totally different environmental pressures than wild animals do. Many of us engage in monogamous relationships, spend long hours in the office, and struggle to keep up with deadlines, bills, and other commitments. At a certain point in human evolution, the adaptive advantage of acute stress was overshadowed by the downsides of that headline-dominating bogeyman, chronic stress.

Robert Sapolsky's book Why Zebras Don't Get Ulcers is the most enthralling treatise on chronic stress I've ever read. It does an excellent job explaining why the daily grind of traffic jams, post office visits, and sitting on hold with the electric company is simply not the "nature of the beast." We didn't evolve with the physiological equipment necessary to withstand these artificial stressors in a healthy way, which is why we (and not zebras) suffer from stress-related chronic illnesses.

Acute stress is adaptive. It helps us make beneficial decisions. The biochemical hallmark of acute stress is the release of epinephrine (adrenaline) from the adrenal glands, which sit atop the kidneys. But if everyday experiences of stress start to aggregate and snowball, they can lead to chronic stress. High levels of circulating epinephrine over the long term, coupled with the release of the stress hormone cortisol, can cause or exacerbate severe health problems, like heart disease, obesity, and suppression of the immune system. Chronic stress can also contribute to the risk of developing depression.

But this month, we're talking about mental illnesses. Acute and chronic stress aren't diagnosable mental illnesses, but anxiety disorders are. So what's the difference? To me, this line is a bit fuzzy. It all comes down to what's happening in the brain, and how that affects an individual's ability to cope.

The brain experiences stress and anxiety in slightly different ways, although they do share some of the same real estate. Anxiety is more akin to fear. An anxiety disorder is diagnosed when that fear is significant enough to interfere with daily functioning, or if it seems to develop without cause. The DSM-IV-TR recognizes the following diagnosable anxiety disorders: generalized anxiety disorder, panic disorder, panic disorder with agoraphobia, phobias, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), separation anxiety, and childhood anxiety disorders. You can read specific descriptions of each anxiety disorder in a publication by the National Institutes of Mental Health here and in a statement released by the surgeon general here.

The neurocircuitry involved in anxiety disorders is largely indistinguishable from that involved in fear reactions. Limbic structures (deep brain structures involved in emotional processing) such as the amygdala and insular cortex show heightened activity in individuals struggling with anxiety. Specific disorders, such as OCD and PTSD, involve specific pathways and behaviors not seen in other states. For example, individuals with OCD have heightened activity in the caudate nucleus of the basal ganglia, a region involved in learning and memory, as well as emotional processing. It appears to be a gatekeeper of signals to the orbitofronal cortex and thalamus, two regions that are overactive in patients with OCD. The orbitofrontal cortex is a critical region for moral judgment, planning, and general executive functioning. The thalamus integrates and relays sensory information to brain regions necessary for its processing.

With recent pushes toward the medical model in modern psychiatry, I wonder if the lines between the terms "stress," "fear," and "anxiety" will continue to blur. The conventional wisdom is that unchecked acute stress may aggregate to become chronic stress, and that chronic stress underpins diagnosable anxiety in a large percentage of the population. Anxiety disorders are the most common mental illnesses in America, affecting around 18 percent of the U.S. population in any given year, and almost 30 percent of American adults across the lifespan. But in a world where everyday stress is a fact of life, in a body that is not equipped to deal with its cumulative effects, this doesn't really surprise me. What do you think?

See all Talk Nerdy to Me posts: www.huffingtonpost.com/news/talk-nerdy-to-me
Like Cara Santa Maria on Facebook: www.facebook.com/pages/Cara-Santa-Maria
Follow Cara Santa Maria on Twitter: www.twitter.com/CaraSantaMaria

Comments

[aloha12u]

09:42 PM on 12/20/2011

The critical distinction between repetitive "stress" syndromes and distress related anxiety
­is that tension driven distress acts as a kind of neuritis (inflammat­ion) and hypersensitivity to real or perceived stimuli. This can be "learned" and conditioned simultaneously into patterned evoked & provoked responses. Consequently, a spiraling sequence of agitation on the nervous system can enact "reference models" evoked or provoked by ideopathic circumstances or previously uncomfortable consequences as further reinforcements (including the inability to escape or evade anticipating a perceived uncertainty or unsettling emotion.) .

These alarm states reverberate as systemic signals to frustrate any realistic resolve. Uncertainty alone coinciding with this impulse towards resolve stimulate intangible mental models,... albeit with potentially excruciati­ng physical pulsing alarms that cycle between cognitive and emotive (interacti­ve) reinforcem­ents. Anticipato­ry anxiety becomes embedded like "memory" with both physical and mental consequenc­es that create both substrate and response in a blind sequence of spiraling intensity. It is real. It is not external, but it is real. I do not believe it is an emotion or a mentalist stasis but essentially physiological at its foundation; while both emotions and cognitive imaging respond parallel to the neurological signals. Point: this is my personal consideration not orthodoxy.

Modeling the tension appears to be the trigger for many, and the practice of mindfulnes­s is successful­, I believe, because it dynamicall­y interrupts this cycle of reinforcem­ent. Interventi­on comes in the form of what you do with and how you "program" the space created by this present minded interrupt.

[JustMyWords]

09:28 PM on 12/20/2011

Trying to define the difference between stress and anxiety simply clouds the issue, and it's not necessary. Anxiety is simply a reaction to a stressor. Instead of an arguing which is which - an argument that's a bit like deciding how many angels can dance on the head of a pin - it would be far more useful to find ways to handle and treat anxiety disorders. Not all doctors or therapists seem to have a handle on the notion. (I've had a therapist suggest that no one ever needs medication, the best way to avoid anxiety is to simply stay away from any people or situations that cause stress. I'm hoping this is the only person who has ever suggested agoraphobia as a cure for an anxiety disorder.)

And I don't have much use for "Why Zebras Don't Get Ulcers." Aside from the fact that it's estimated that roughly 90% of ulcers are caused by h. pylori, not stress, how do we know that animals don't have stress related physical ailments? To me, it seems as though Sapolsky started with a nifty title and created a theory to go along with it. Maybe he's right, maybe he's not; it just didn't feel like a very good way to make a case to me.

[aloha12u]

09:13 PM on 12/20/2011

http://en.wikipedia.org/wiki/Category:Anxiety
good page of indexed terms relating specifically and generally to categories that are commonly identified as anxiety syndromes.

[puyallup1]

12:29 PM on 12/20/2011

an omitted, yet important point from the excellent article is the importance of a physical stress release. Exercise, in any form, is what animals always have to help balance the "stresses". Our brains have NEVER had the amount of daily input as they do today....and it will only increase daily with all the gadgets, etc. (Think of how many inputs our parents received: 3 TV channels, a coupla radio stations and a newspaper) This is NOT to say the brain can't handle it. I believe it truly can. In fact, THRIVE. However, the physical effects are new in that they are like a cascade of inputs/stresses.
We will have to take care of our physical bodies MUCH better to counteract and, thus, thrive. Even if it's a 30-minute walk per day.

[othyflotsam]

03:04 PM on 12/19/2011

Hello Cara Santa Maria hope all is mango-ee. hehe. I think Iam the "zebra" but my stripes are horizontal. No worries

[kgeorge345]

03:04 PM on 12/19/2011

Thanks for this article, Cara. It's an important subject, especially when you go about deciding how to treat it. For anxiety sufferers, you might want to look at this link, which discusses some techniques of dealing with you anxiety. I found it really helpful: http://www.onlineceucredit.com/ceus-online/bcs-anxiety/continuing-education.html

[minpin]

11:23 AM on 12/19/2011

Hi, I have clinical depression and have accepted that I'm on medication for life. Getting others, even the medical profession or particularly them, is a battle. Recently, I have C-spine surgery with fusion. I kept telling them no morphine (a depressant) and even though they were giving me antidepressants (three types) they wouldn't stop the morphine. Morphine was my pain med and nothing else would do. When I told them I'd abused valium and didn't want it, ever after these "professionals" threw that in my face with every conversation we had about pain killers. Not "professional" in my opinion.

[Totalitarianliberalism]

04:15 AM on 12/19/2011

Does the Professor understand that a zebra doesn't stress about speaking in public because THEY DON'T SPEAK?

[methodman]

12:22 PM on 12/18/2011

Ariel You need to understand that in my case my public side is quirky and if you were to whisper two words in my ear every 1/4 of a second with a noticable disruption. That isn't made up!!!! It stops you because you also accept other people with disabilities who interrupt you with their quirks too and you help them in ways that independent minded people don't have to ask for assistance. For example my wife has one arm and cooks like a two armed person so I have to hold bowls with out the normal resistance. So they slide around. She would stack items in the refridgerator in a pile. My disability is like that game BASH where you had a head and feet and blocks piled through and you would knock out the blocks while not tumbling the head. Well when I first started I was unable to process blocks. So I would see what she wanted reach in grab that bowl between the items and they would come tumbling out. It got the wife very irritated. I have started to process that and my back really starts to hurt. But it is processing something THAT IS THE TRUTH I AM NOT MAKING THIS UP NAYSAYERS!!!

[Ariel Bonzai]

10:12 PM on 12/17/2011

I didn't realize anxiety disorders were considered mental illness-- there'an attitude about mental illness limiting perception to extremes; schizophrenia, , manic depression,, personality disorders are what we think we hear mentally Ill . I believe that all of us are mentally ill and anyone who insists he or she is normal is sicker than anyone. I know folks with OCD, personality disorders, anguish of autism, Tourette's, and bi polar disorder. No wonder I have an anxiety disorder, but PTSD. It is presently an epidemic for teachers. Our fears and concerns are viable--so disorder seems like a stretch .
That alarm goes off with good reason. We cannot silence it, pretend issues aren't there. I can't in good concious live in Xanax haze while the future goes up in flames because capitalists want to control schools, yet , telling folks about today's public schools sounds like an Orwellian nightmare. Folks probably assume youre insane, ranting about profiteers disguised as philanthropists and insidous propaganda. We joke about crazy being a prerequisite for careers in education. Prudence usually turns educators into benign sleepwalkers. And that's crazy. Either way there is little benefit in the constant panic i faceconfrint. I see & feel the toll it's taking. Yet if I don't act, things will only get worse . Maybe the cure is pro action

[nypoet22]

12:47 AM on 12/18/2011

just because we're paranoid doesn't mean they aren't out to get us ;-)

[Ariel Bonzai]

10:14 PM on 12/18/2011

You're telling me... They are out to to get us. But we needto get them first.

[GlennAlb]

09:47 PM on 12/17/2011

Ecoanxiety and solastalgia? Perhaps you can add the realm of psychoterratic (earth related) stress to the list. See: http://healthearth.blogspot.com/2011/09/creating-language-for-our.html
for the positive and negative conditions connected to our relationship to the environment. As development pressures (e.g., gas fracking) and climate change unfold, unfortunately, negative psychoterratic conditions proliferate.

[SeeTheFnords]

05:01 PM on 12/17/2011

Having been a research assistant for a PhD candidate who wrote about stress, I can add something here. There are two types of stress: eustress, and distress. Think of eustress as that rush you feel as you're racing towards the finish line, while distress is what you would be feeling if you tripped over a rock and broke your ankle.

The basic theory is that Anxiety is caused when Distress persists over a long period of time, without resolution or adaptive coping.

I would suggest reading some of the works by the Canadian pioneer stress researcher Dr. Hans Selye: http://en.wikipedia.org/wiki/Hans_Selye

[aloha12u]

04:36 PM on 12/20/2011

Yes the critical distinction is that tension driven distress that becomes internalized as a kind of neuritis (inflammation of the nerves) can "institutionalize" itself inot a regressive spiral of self sustaining pressure to resolve literally intangible mental models and excruciating physical alarms that cycle between cognitive and emotive (interactive) reinforcements. Anticipatory anxiety becomes embedded like "memory" with both physical and mental consequences that create both substrate and response in a blind sequence of spiraling intensity. It is real. It is not external, but it is real. The progressive burnout leads to exhausted futility, despair and potential degrees of sleeplessness and fatigue...classic consequence of depression states result if left to run its full course. Modeling the tension appears to be the trigger for many, and the practice of mindfulness is successful, I believe, because it dynamically interrupts the cycle of reinforcement. Intervention comes in the form of what you do with the space created by the present minded interrupt. Hope that helps someone out there... Bruce

[methodman]

11:05 AM on 12/17/2011

I have found doing yogic breathing increases patience.. there are a wide variety of formalized methods really works wonders. the other issue is people with disabilities and who are somewhat independent may develop abruptness to ward of either nay-saying family members or protect themselves from people who want to harm them without the language skills. The business culture in America is so unfriendly to the disabled that most will not be given a fair shake and with the tea party rascals who think disabled people belong in a cardboard box by the side of the road what is a disabled person supposed to do?

t

[ron17]

06:20 PM on 12/17/2011

Thank you for acknowledging the problem of the "nay-saying family members"...who in my personal situation bring out the abruptness in me towards thier ignorance.

[gmikejake]

08:48 PM on 12/17/2011

Thank you. Our regressives are constantly trying to undermine Medicaid, that portion of our fairly leaky safety net, that is intended to provide medical care for our most vulnerble citizens living in poverty, mostly children, seniors, and persons living with serious disabilities. Their "Ryan" plan would effectively demolish Medicaid as we know it in just a few years as the retired folks on Medicare would become impoverished and then have to switch over the Medicaid. Medicaid is already down to "bare bones" in many cash strapped, politically conservative states with no ability to raise revenues. Mental health implications? There are many. For example, just try to find a board certified child psychiatrist in most rural areas that accepts Medicaid. Many people have to drive hundreds of miles after waiting for long periods of time for an available appointment to just access the beginnings of such a service.

[neverknowwhattoputhere]

03:31 AM on 12/17/2011

The difference between when I'm feeling anxious and when I'm feeling stressed.

Anxious = I'm worried, but can generally function like a normal human being except I may be a bit quieter and more withdrawn.

Stressed = If you scrape that metal spoon on that ceramic bowl one more time I am going to chop your arm off and feed it to my dog.

[Robben Wainer]

02:58 AM on 12/17/2011

Hello,

As my mid-life crisis began with a journey in protoplasm and progesterone. The Zebra does not always satiate the eye of a needle with resolutions. The heretical refrain, as I am no longer my brother's keeper, is one of a person who may feel their desire sustains pro-creativity and freedom of self expressions of vitality. Those who are in the clouds must still wait. The way to recourse from sin, and carnal knowledge is to erect the the surruptitious need for anti-thetical love, reasons, libido and scruples.

[eric14]

12:50 PM on 12/17/2011

Hybrid? Battlestar Galactica?