primitive cultures have avoided the depression epidemic afflicting
industrialized nations. In a provocative book, a clinical psychologist suggests
that adopting more “hunter-gatherer” habits can help us escape the
blues.
about one in four Americans — more than 70 million people — will meet the
criteria for major depression at some point in their lives. The rate of
depression in industrialized societies has been on the rise for decades — it’s
roughly 10 times higher today than it was just two generations ago. How can
people possibly be so much more vulnerable to depression now? And how do you
make sense of the fact that even though antidepressant use has skyrocketed in
recent years, the rate of depression in the United States hasn’t declined, but
rather increased?
As a clinical psychologist, I believe the answer is rooted in our way of life.
I say this because researchers have assessed modern-day hunter-gatherer bands —
such as the Kaluli people of the New Guinea highlands — for the presence of
mental illness, and they found that clinical depression is almost completely
nonexistent among such groups.
Despite being much more likely to experience tragic events like the death of a
child or a crippling illness, and living with none of the material comforts or
medical advances we take for granted, they’re largely immune to the plague of
depressive illness.
But how are hunter-gatherers able to weather life’s storms so effectively?
Based on the available research, it seems that the hunter-gatherer lifestyle is
profoundly antidepressant. As they go about their daily lives, they naturally
wind up doing things that keep them from getting depressed, things that change
the brain more powerfully than any medication. These range from exercising
regularly and eating plenty of omega-3 fats to belonging to active social
networks and getting enough sleep.
For most of human history, everyone benefited from the antidepressant effect of
these ancient lifestyle elements. But over the past few hundred years,
technological evolution has proceeded at a relentless pace. And as many
protective features of that way of life have gradually disappeared, the rate of
depression has begun to spiral out of control.
Our Stone Age brains just weren’t designed to handle the sedentary, isolated,
indoor, sleep-deprived, fast-food laden, stressed-out pace of 21st-century
life.
Based on this information that shows lifestyle might be the most important
factor in producing (and beating) depressive symptoms, my colleagues and I at
the University of Kansas have developed a treatment called “Therapeutic
Lifestyle Change,” or TLC. It incorporates six major protective lifestyle
elements we need to reclaim from our ancestors: dietary omega-3 fatty acids,
mentally engaging activity, physical exercise, sunlight exposure, social
support and adequate sleep.
TLC has yielded exceptional results in our clinical trials; the rate of
favorable response has been more than three times higher than that of conventional
antidepressant treatments.
When you consider the far-reaching effects of the lifestyle changes below, it’s
easy to understand why this approach is so effective — and why for anyone
struggling with depression, it is almost certainly worth trying.
Feed Your Brain
includes wild game that feed on grass, and fish that feed on algae — both
abundant sources of omega-3 fatty acids. Conversely, the extraordinary rise in
depression rates over the last century has closely mirrored the disappearance
of omega-3 fats from the Western diet, which has come to rely more on grains
(and grain-fed livestock) than wild game and plants. In countries where people
still get a better dietary balance of omega-6s from seeds and omega-3s from
grasses, leaves and algae, depression tends to be substantially less common.
But how, exactly, does an imbalance of the fats we eat make us more vulnerable
to depression? Neuroscientists have identified three mechanisms that play a
role:
Serotonin: Serotonin is a neurotransmitter that helps turn off the
brain’s stress response. But when brain cells don’t have enough omega-3 fats,
they have trouble understanding the message of serotonin, increasing a person’s
vulnerability to the kind of out-of-control stress response that leads to the
onset of depression.
Dopamine: Lack of omega-3s also scrambles the messages of dopamine, a
neurotransmitter that activates the left frontal cortex — the part of the brain
that puts us in a good mood and pushes us to go after the things we want.
Inflammation: When unchecked by a balance of omega-3s, omega-6 fats
promote inflammation throughout the body. Over time, chronic inflammation
triggers a reduction in the production of tryptophan, the primary building
block of serotonin. It also impairs the hippocampus, which is critical to
memory function. And it triggers the stress hormone cortisol, which has its own
set of depressive effects on the brain.
A key element of the TLC protocol is to begin taking a daily omega-3 supplement.
The easiest source is fish-oil capsules. Fish oil is the richest natural source
of both EPA and DHA, the two omega-3 molecules that play an important role in
the brain. I recommend starting a daily dose of 1,000 milligrams of EPA and 500
milligrams of DHA to all of my patients.
If you currently have symptoms of depression, or if you want to help prevent
the onset of illness in the future, this is the dose I suggest you begin with,
as well. (If you are taking any medications, particularly blood thinners, check
with your doctor first.)
Don’t Think — Do
where people are usually busy either chasing dinner or lingering with the
community after the meal, people in industrialized societies often find
themselves alone, without any kind of activity that absorbs their full
attention — conditions ripe for rumination.
Rumination appears to be an instinctive human response when something goes
wrong. It’s as if we’re hardwired to replay our trials and tribulations over
and over — perhaps to figure out what might help us prevent similar negative
outcomes in the future. But after a brief period of intense pondering, we
usually hit a point of diminishing returns, when any more dwelling is a waste
of time — and a real source of stress.
If you find yourself locked in the vise grip of rumination, I can offer some
words of reassurance — breaking the habit may sound difficult, but the process
is surprisingly straightforward. The first step involves learning to notice
when it’s happening.
One helpful strategy is to start monitoring your thought process every hour or
so, just to see where your attention is. Set an alarm on your watch or phone to
remind you to take note of your state of mind. Then, when it goes off, jot down
any worries or negative thoughts you were entertaining at the time.
As you become increasingly tuned in to your mental life, you’ll notice that
some situations are particularly risk-prone. The research on this point is
clear: People typically ruminate when they have nothing else to occupy their
attention.
This leads to the second step: Learn to redirect your attention. In most cases,
it just takes a few minutes of immersion in a good alternative activity before
the spell is broken.
While there’s no one-size-fits-all formula when it comes to finding engaging
activities, some things turn out to be anti-ruminative for just about
everybody. These include participating in shared activities, whether it’s
building a fence or playing a game of pickup basketball, or getting involved in
an active conversation — especially if it’s about something other than what’s
bothering you.
If you’re engaged in a mindless activity that itself leads to rumination,
listening to upbeat music or books on tape can give your mind somewhere else to
go.
Move Your Body, Shift Your Brain
exercise is a key to maintaining physical health, few realize that it’s equally
important for preserving mental health. Like an antidepressant medication,
exercise increases the activity of brain chemicals like serotonin and dopamine.
It also stimulates the brain’s release of a key growth hormone (BDNF) that
helps reverse the toxic, brain-damaging effects of depression. It even sharpens
memory and concentration, and helps us think more clearly.
That said, motivation to exercise can be hard to come by. One reason might be
that our hunter-gatherer forebears got so much physical activity in the flow of
daily life that they actually avoided extra exertion whenever possible. They
followed a simple rule: Spend your energy only on activities that have a clear
purpose or offer immediate reward. This rule was so important to people’s
survival that it became part of our genetic legacy.
Many people discover this when they approach a treadmill or stationary bike and
feel as if a part of their brain is screaming out, “Don’t do it! You’re not
actually going anywhere on that thing! Conserve the calories!”
Fortunately, there’s a way out of this dilemma. Yes, we’re genetically wired to
avoid extraneous exertion, but what about necessary or pleasure-producing
activity? As it turns out, whenever we’re caught up in enjoyable, meaningful
activity, our tolerance for exercise goes up dramatically. So when you make
activity purposeful or pleasant (riding your bike to work, dancing, playing a
team sport, walking to the store instead of driving), you’re much more likely
to do it.
When it comes to hitting the gym, it can really help to work out with someone
else. Spending time with others tends to be highly absorbing, so it makes the
workout pass quickly; it also gives you the mood-elevating benefits of social
support. Finally, a workout partner can provide the initiative that depression
steals away.
How much exercise is necessary for an antidepressant effect? Incredibly, a Duke
University study found that a brisk half-hour walk three times a week proved to
be more effective than the antidepressant medication Zoloft. So 90 minutes of
heart-rate-elevating exercise is enough to feel a difference. As one personal
trainer told me, “I don’t think I’ve ever seen someone leave the gym in a worse
mood than when they arrived.”
Let There Be Light
outside all day, every day. As a result, our eyes have special light receptors
that respond only to the brightness of natural outdoor light, which is 100
times brighter than typical indoor lighting. If you’re like most people who
spend most of their time inside, your eyes’ light receptors simply aren’t
getting the stimulation they need. And that can have a major effect on both
your brain chemistry and your body clock.
Bright light stimulates the brain’s production of serotonin, that crucial
chemical emissary that boosts feelings of well-being. According to the latest
research, people usually feel some elevation of mood within an hour or two of
exposure to bright light. One recent study showed that people under the
influence of bright light are less likely to argue or fight with others.
When we’re deprived of ample light, however, serotonin can fall and the
light-sensitive body clock falters: Hormone levels get out of whack, sleep
grows erratic, and energy ebbs and flows at all the wrong times. So resetting
the body clock each day is important, and it all hinges on those specialized
light sensors at the back of the eyes.
How much bright light is required to keep the clock running on
time? Fortunately, it’s not that much. For people suffering from
depression, 30 minutes of light exposure each day is all it takes to provide an
antidepressant effect. However, the light needs to match the brightness of a
sunny day — an intensity of at least 10,000 lux — in order for the 30 minutes’
worth of exposure to do the trick.
Getting your bright light exposure by spending some time outside has some clear
advantages. Mere exposure to a natural setting can lower stress hormones and
reduce feelings of anxiety; this holds true even when we’re enjoying an urban
park or suburban backyard. We can also easily combine time outside with other
antidepressant lifestyle elements, like exercise and social interaction.
For those in less-than-hospitable climes, however, using a 10,000-lux light box
during the winter months has advantages of its own. As long as you have access
to a power supply, it will give you all the light you need with the flick of a
switch.
Get Connected
our ancestors lived in small, intimate social bands, facing together the
relentless threat of predators, the forces of nature and hostile neighboring
clans. Such a clannish sensibility is still keenly present among modern-day
foraging bands and other traditional, pre-agrarian societies. According to
anthropologists, “alone time” is virtually unknown among such groups.
In the industrialized West, on the other hand, we’ve strayed far from this
sensibility. According to the latest research, 25 percent of Americans have no
intimate social connection at all, and countless others spend the bulk of their
time by themselves. One recent study found that half of all American adults
lack even a single close friend they can rely on.
Isolation is a major risk factor for depression. Those who lack the benefit of
a meaningful social connection are highly prone to becoming depressed,
especially in the face of severe life stress. And, sadly, once people start
experiencing severe depressive symptoms, they tend to withdraw even further
from the world around them. In large part, this is because the brain responds
to depression as it does any other serious illness, directing us to avoid any
activity, especially social activity, so the body can focus on getting well.
toll on friendships, because the depressed person feels as if he’s doing his
friends a favor by pulling away, and his friends, in turn, feel rejected.
It can be helpful to start by disclosing your struggles: Honest disclosure is
essential to maintaining the health of any friendship. It can also be helpful
to do a little educating. When your friends understand that depression is an
illness and withdrawal is a symptom, it’s easier to take your disappearance
less personally.
The most useful thing for treating depression, by far, is to spend regular time
together in shared activities: walking, working out, playing games, going to a
concert, attending a play and so on. Such activities are especially effective
in combating depressive rumination, and they promote activity in the brain’s
left frontal cortex, which itself provides a direct antidepressant effect.
We ask each patient in the TLC program to adopt the goal of scheduling at least
three such activities a week with friends or other close acquaintances.
Sleep Well
hunter-gatherer chasing a lion deep into the night; most traditional societies
sleep when it’s dark and work when it’s light. Meanwhile, the average American
stays up well past dark and gets only 6.7 hours of sleep a night.
Because sleep is so essential to our well-being, it takes only a few nights of
deprivation before adverse effects start piling up: Memory and concentration
wane, mood turns irritable, judgment grows poor, coordination deteriorates, and
immune function declines.
Sleep disturbance and depression go hand in hand. The loss of slow-wave sleep —
the most restorative type of slumber — can directly account for many of
depression’s most debilitating features.
Several elements of the TLC program are aimed at enhancing sleep. Physical
exercise leads to more restorative slow-wave sleep. Daytime bright-light
exposure strengthens the body clock, making it easier to fall asleep and stay
asleep. But if you find you’re still not getting quality sleep because of
insomnia, here are some suggestions:
• Use your bed only for sleeping (not reading, working or watching TV).
• Get up and go to bed at the same time every day. This helps keep your body
clock on track. Avoid napping during depressive episodes. It can reduce your
sleep drive, and evidence suggests it can cause a reduction in slow-wave sleep.
• Avoid drinking alcohol before bed. Using alcohol (even a drink or two) to
relax and fall asleep can produce frequent awakenings throughout the night.
• Turn down your thermostat at night. Our remote ancestors always slept outside
or in open huts, where it got noticeably colder around bedtime. A nighttime dip
in temperature sends a primal signal that it’s time to sleep.
If you are currently being treated for depression, consult with your health
professional before adjusting your regimen or treatment plan. But don’t
underestimate the positive impact that lifestyle shifts like these can have.
Beating depression may begin with recognizing that we were simply never
designed for the frenetic pace of modern American life. By reclaiming the
protective features of the past and integrating them into the present, I believe
we can overcome depression, once and for all.
professor of clinical psychology at the University of Kansas. This excerpt is
reprinted from his book The Depression Cure by permission of Da Capo
Lifelong Books, a member of the Perseus Books Group.
