Successful Aging: A Neuroscientist Explores the Power and Potential of Our Lives

by Daniel J. Levitin

As adults, we can succumb to depression, an intractable disease that affects approximately 15 percent of Americans. This number is more or less the same across continents. I say intractable because in spite of the great advances made in neuropharmacology, antidepressant drugs tend to work only 20 percent of the time.

Insomnia, a hallmark of aging for many, is an often overlooked risk factor for late-life depression, affecting 25 percent of men and 40 percent of women in their eighties. Changes to the integrity of the hypothalamus, which helps regulate sleep-wake cycles, as well as age-related reductions in the production of melatonin and other neurohormones, also contribute to insomnia. If you can’t get a good night’s sleep, all kinds of neural and physiological systems begin to go haywire. Practicing good sleep hygiene, as detailed in Chapter 11, is almost always more effective than medication.

SSRIs—selective serotonin reuptake inhibitors. SSRIs cause whatever serotonin is in the brain to linger around the synapses longer—it’s as though you’re giving the brain more serotonin, but you’re just squeezing more mileage out of the serotonin that’s already there. A fad in these drugs resulted. SSRIs such as Prozac were widely prescribed for people with depression.

Psychotherapy can change the structure of the brain. This isn’t at all surprising, given what we’ve seen throughout this book—that every experience changes the brain. In particular, cognitive behavioral therapy engages similar neural mechanisms as antidepressant medications, but without the side effects of withdrawal. Long dismissed by physicians who were more focused on pharmaceutical, electroshock, or other “medical” interventions, talk therapy has proven its effectiveness, and even its superiority. For depression, it is at least as effective as antidepressant drugs in the short term, and over the long term, we see less relapse—two years after intervention, people who received prior cognitive therapy are doing better than people who simply stayed on medication.

One of the most important findings about coping styles in depression was made by Susan Nolen-Hoeksema, who distinguished rumination from distraction and found that distraction was far more effective than rumination in coping with bad fortune, and that rumination was associated with significantly longer periods of depressed mood. People who ruminate have a tendency to repetitively focus on what went wrong, and the causes and consequences of what went wrong, over and over and over again. They lock themselves in their rooms; they stay in bed; they catastrophize the future. All of us have a tendency to do this, to varying degrees. Withdrawal from the world after a negative experience is evolutionarily adaptive—it gives us time to heal and to reflect productively on what went wrong so that we can avoid or correct patterns of our own behavior that can lead to trouble. And to some extent, the sadness that rumination steeps us in feels good: It releases the neurochemical prolactin, which is calming and soothing—the same hormone released in mothers and their infants while nursing. But excessive rumination increases stress hormones. It drives a downward cycle of unhappiness and can trigger one or multiple episodes of major depression. Rumination interferes with interpersonal problem solving, depletes motivation to engage in constructive behaviors, and impairs social relationships. Rumination also feeds the destructive aspects of mood-dependent memory retrieval because the hippocampu...

There are other ways to break the cycle of depressive rumination besides distraction. Meditation is one of them—it doesn’t work for everyone but it does work for many. Depressed people have a magnified sense of self-consciousness.

One of the surest ways to get over depression is to help others—this allows you to step outside of yourself and your preoccupations. Helping others is powerful medicine.

Much of our motivation to do things is controlled by our brains and by the hormones and neurochemicals circulating within. (Hormones are a kind of neurochemical that works both inside the central nervous system and outside of it.) We tend to think that our motivation and desire to do things are driven by our own ideas, our will. We decide to go out for a brisk walk and then we do it. But the hormones are the hidden strings that pull our bodies. For example, estrogen production in women follows a monthly cycle and reaches its peak around the midpoint of the menstrual cycle. Women are far more likely to walk more at this point than at any other point in the cycle. It’s been speculated that this is the time of the month when women get cabin fever and want to explore the territory around them to find the most desirable mate—even if at a subconscious level. Higher estrogen is also related to increased competitiveness and possibly to reduced fearfulness.

In both women and men, testosterone appears to regulate the seeking and maintenance of social status, including sexual status and the displays that go along with seeking attractive mates. Both men and women who are high in testosterone are more likely to engage in risky activities, such as gambling and having sexual relations with multiple partners. Indeed, most people in monogamous relationships show lower levels of testosterone than those not in committed relationships. You can imagine an evolutionary basis for this, that people in a committed relationship will do a better job at staying together, and parenting, than people who are not, and this will enhance the ability of their offspring to seek a committed relationship, reproduce, and become parents themselves.

A feature of aging is that both sex-linked hormones, testosterone and estrogen, decline with age, and these declines have well-documented effects. First, there is a decline in interest in sexual activity. When Socrates asks sixty-eight-year-old Cephalus about his libido, Cephalus responds, “Most gladly have I escaped the thing of which you speak; I feel as if I had escaped from a mad and furious master.” A sixty-eight-year-old friend of mine, H., whom I’ve known for forty years, was one of the most sexually active people I’ve ever known until a few years ago, when his libido just up and disappeared. “I can’t believe how much time I have now to do other things,” he notes. Indeed, we might look at our life span as occurring in three stages: childhood, before the pubertal sex hormones kick in; puberty to late adulthood, when sexual desire dominates many of our thoughts; and old age, when we are back, like children, to wanting friends to play with, but not thinking so much about sex.

reductions in testosterone and estrogen lead to fuzzy thinking and losses in a number of areas: cognitive function, memory, motivation and mood, immune-system function, and bone density. It is wise, after age fifty, to have your hormone levels checked and possibly restored, pharmaceutically, to physiological levels if you do not have a medical condition that precludes this. Hormone replacement therapy, in both women and men, can restore quality of life and energy in a way that nothing else seems to.

worldview about who’s in charge of your life. If you tend to think that the course your life takes is governed by other people, systems, organizations, and circumstances, you’ll tend toward “accepting your fate” and not exerting yourself much to change things. In technical terms, this is called having an external locus of control (the external world is in control of you). If you tend to think otherwise, that you can change the story of your life, you have an internal locus of control and are typically more motivated, more driven, to make changes.

Believing you can’t change your life ends up being a self-fulfilling prophecy because you bypass opportunities that could help you change your life.

Did that for 38 years😢

Immersing yourself fully in whatever activities you engage in—work, leisure, family, community—is protective against cognitive decline and physical illness. The rewards from doing things that please you lift your mood, and strengthen the immune system, increasing the production of cytokines, T-cells, and immunoglobulin A.

There is a tendency as we age to resist change, owing to a variety of factors. Depletion of dopamine and deterioration of dopamine receptors in the brain lead to a lack of novelty seeking—we’re chemically less motivated to look for new experiences or to learn new things. Bodily and cognitive limitations make learning and doing new things more difficult. And memory! Our memories and perceptions are based on millions of observations of things being a certain way; our prediction circuits are basing their calculations on what happened over and over again in the past. The intact memory system becomes a competing force against our brains’ quest to stay current. Add to that the hippocampal volume reductions, which make it harder to store new memories and easier to retrieve old ones, and you have a formula for conservatism.

Problems can arise in aging when new information contradicts prior learning or doesn’t fit into the well-worn pathways of your knowledge base. Then the general slowing down of cognitive processes plus the decline in reasoning ability that accompany old age can cause difficulties that take a major surge in motivation to overcome.

people who are curious (the first C in the COACH principle) and who enjoy learning for its own sake do better in a whole big basket of life outcomes.

intrinsic motivation is always more powerful than extrinsic motivation.

People with a fixed mind-set believe that their qualities and abilities don’t change; they say things like: I’m not good at math. I don’t remember people’s names. I don’t understand technology. I’m not the athletic type. I’m too old to change. People with a fixed mind-set generally have an external locus of control. They are low in Curiosity and Openness. They aren’t interested in learning new things and don’t think that the payoff of learning new things will be worth the effort.

As we age, our motivations to be recognized for our achievements, and to rack up more and more achievements, tend to decline—that is, older adults tend toward being more intrinsically than extrinsically motivated. Older adults show increases in their motivation to use their accumulated knowledge, to help others, to preserve their resources, and to maintain a sense of autonomy and competence.

Happiness is an odd construct. It is highly subjective, variable, and dependent on a number of factors, such as culture and expectations. It’s also fiendishly relative, context dependent, and based on social comparison theory.

Happiness may also be subject to an observer distortion effect in that trying to assess it all the time may actually interfere with it. Probing happiness stops the flow of activity and pulls you out of time to inspect it. And the one constant of happy people seems to be that they don’t think about happiness—they’re too busy doing things and being happy to stop and think about it. Happiness therefore is a judgment made in retrospect.

The biggest tip of all to promote healthy emotions as we age is to find a way to help others. It is much more difficult to be depressed or feel dreary if you are working to make someone else’s life better.

One of the keys to a long health span and a long life is social connectedness.

Loneliness is associated with early mortality. It has been implicated in just about every medical problem you can think of, including cardiovascular incidents, personality disorders, psychoses, and cognitive decline. Loneliness can double the likelihood of developing Alzheimer’s disease. It increases the production of stress hormones, which in turn lead to arthritis and diabetes, dementia, and increased suicide attempts. It leads to inflammation, increasing proinflammatory cytokines such as interleukin-6 (IL-6), and it negates the beneficial effects of exercise on neurogenesis, the growth of new neurons.

People can feel lonely even when surrounded by others, such as in the middle of a party or inside a large family. Loneliness is a feeling of being detached from meaningful relationships, and that may arise from feeling unacknowledged, from feeling misunderstood, or from a lack of intimacy.

Being unmarried raises the risk of loneliness and a host of health-related problems, but being married doesn’t help in all cases—not all marriages are happy ones.

Social isolation and loneliness are associated with reductions in levels of the neurotransmitter glutamate. Glutamate is the most abundant neurotransmitter in vertebrates and is important for transmission of signals throughout the cells of the brain.

Social isolation and loneliness can even change your genes. Social isolation, loneliness, and depression affect gene expression, causing increased inflammation in the brain and decreased production of antiviral interferon. Lonely people have increased activation of the HPA axis, causing them to be hypervigilant about social threats. They might believe that most people in the world are out to harm them, humiliate them, or behave derisively or dismissively toward them. In this respect chronically lonely people resemble people with PTSD.

Music often occurs in social settings like parties, restaurants, and political rallies, and there is evidence that listening to music in groups releases oxytocin, the hormone that facilitates social bonding.

Paxil and Zoloft, two SSRIs (selective serotonin reuptake inhibitors), although they are primarily known as antidepressants, have been shown to ease social anxiety, to help people enjoy their interactions with others. Don’t give up if treatment doesn’t work quickly—they are subject to what we call “therapeutic lag.” Finding the right medication and dose for your situation can take some trial and error.

Positive psychology grew out of a belief that psychology’s focus on disorders and problems of adjustment was ignoring much of what makes life most worth living. Positive psychology has found that people who practice gratitude simply feel happier.

a number of studies have shown that religious people are happier than nonreligious ones. There are a number of explanations for this but they’re not what you might think: Religious people aren’t happier because they believe in God or because they feel the comfort of God watching over them; these may be important to them and give them a sense of purpose, moral or ethical grounding, or simply the belief that they are doing the right thing, but those are not ingredients of happiness. The research suggests that religious people feel happier because religion promotes gratitude through prayers and gives them a social network, along with a sense of purpose and meaning—three things that benefit most of us, regardless of where they come from. Those social benefits appear also to accrue in the nonreligious who join a music listening group, volunteer in a soup kitchen, or have block parties with their neighbors. And religious people who are not part of a community do not seem to enjoy the high levels of happiness of those who are in one.

Losing a spouse, through late-life divorce, illness, or death, can be a time of profound difficulty.

how we relate to the world. Middle-aged adults tend to direct their energy toward bringing their environment in line with their own wishes—they renovate and build houses, for example, and do other things to mold their world to their liking. Older adults typically focus on changing themselves to accord with their environment. To meet the challenges of aging, older individuals increasingly need to resort to strategies of adjusting expectations and activities in order to pursue more attainable goals when the kinds of activities that characterized their youth become more difficult to do.

Socioemotional selectivity theory states that as we age, we become increasingly aware of our shortening future time horizon. This awareness leads us to prioritize emotional meaning, emotion regulation, and well-being. There is also a developing positivity effect—older adults pay more attention to and remember more positive experiences than younger adults do. Together, these may help buffer against declines in objective well-being and lead to initial increases in subjective feelings of well-being and positivity in older adults.

A belief that we can exert some control over our environment is essential for our well-being and is believed to be a psychological and biological necessity.

At any given time, 30 percent of the population is experiencing chronic pain—which means they’ve been in pain and they’ve had that pain for more than three months. For older adults the number is closer to 40 or 50 percent. The odds of experiencing chronic pain at some point in your life are one in two. More people are in chronic pain at this minute than have cancer, heart disease, or diabetes combined.

of people who are in chronic pain, nearly half have back pain. About one person in five has neck pain and another one in five has arthritis.

for every ten years you are in chronic pain, your life span is lowered by one year. Put another way, chronic pain confers on you a risk-adjusted age of six years higher than your chronological age. If you’ve got chronic pain at age seventy-four, you are effectively eighty.

Chronic pain increases and peaks in our fifties and sixties, and then declines in our seventies and older. These numbers could arise because older adults become more stoic and stop complaining about it, or it could be that they simply don’t have it anymore.

The sensation of pain is actually generated in the brain, even though we usually experience it in a specific part of the body. In other words, your toe may hurt, but the “hurt” is occurring in the part of your brain map that represents your toe. This is why if we shut down your brain, through sleep, loss of consciousness, or certain drugs, the pain goes away. Or why, if we block the transmission of neural firings from your toe to your brain, the pain goes away. This might be done with a topical anesthetic or an intravenous nerve-blocking agent. Either way, no distress signal from the sensory receptor reaches the brain, and so no pain is felt. As we saw in the perception chapter (Chapter 3), you can experience pain even when there is no sensory input, such as with an amputee’s phantom limb pain. Thus, pain is a brain-based phenomenon.

Pain also has an emotional, affective component; that is, we don’t consider it pain unless we experience it as unwanted and undesirable. The same sensation of someone pressing aggressively on your neck is interpreted differently if it’s from an attacker or a massage therapist.

Paresthesia is the general term that applies to any kind of abnormal skin sensation, including numbness, tingling, chilling, or heat sensations that are not painful. When they are uncomfortable, they are called dysesthesia.

mental anguish is related to pain. Grief, for example, can be felt quite physically, and stress or sadness can lead to migraines, fatigue, gastric upset, and so on. Because all pain is ultimately brain-based, there is no scientific reason to separate mental, emotional pain from physical pain.

(Tickling is very interesting from an evolutionary standpoint. In effect it is a simulated false threat—someone touching you in a place that is vulnerable [e.g., belly, neck]. This is why tickling only “works” if it is someone you trust doing the tickling—otherwise it is aversive. Nonhuman primates love tickles as much as human infants, and a dog’s joy having a belly rub is probably related to this.)

The cultural backdrop in which we experience pain is one of the factors that contribute to the psychology of pain and to the attribution of that pain. The way people are injured influences their neuropsychological state, which in turn affects the way they recover. Soldiers who were shot might see their injuries as heroic and part of a noble cause. Convenience store clerks who were shot might have no such positive framing—they might see themselves as victims. The store clerks would be more likely to suffer from depression and far more likely to become addicted to opioids. Context matters. As psychological scientist Steven Linton says, “I have personally witnessed a man stick a rusty nail through his arm without the slightest complaint or flinch, while as a child I experienced a simple injection as excruciating.”

Taking a placebo—an inert pill or procedure that you are unaware is inert—releases the brain’s natural painkillers, endogenous opioids. One of the ways we know this is that administering naloxone, a drug that blocks the receptors for opioids, undoes the placebo effect. Neuroimaging shows that the pain-relieving aspects of placebos are recruiting brain circuits in the anterior cingulate, nucleus accumbens, and middle frontal gyrus—the same regions that generate our endogenous opioids.

People who are in enriched environments—with lots of things to see, listen to, and do—experience less pain than those in simpler environments, and this sort of distraction diminishes pain signals in the insula and primary sensory cortex. Effective distraction while in pain includes exercise, hobbies, interesting conversation, practicing yoga, meditation, socializing, listening to soothing music, or immersing yourself in nature. Even when the distracting activity is forced on an individual in pain, it leads to a reduction in pain and an increase in the body’s production of its own organic opioid analgesics.

new migraine drugs Aimovig, Emgality, and Ajovy. We still aren’t sure what causes migraines, but these drugs have been life changing for migraine sufferers—they only have to be administered once a month and they act as a preventative.