Biology of the Binge: The Biochemical Link Between Depression and Food

Many of us have experienced the instantaneous connection between food and mood. We may find ourselves crunching nervously through bags of potato chips when under pressure for example, or slurping down containers of cool and silky chocolate ice cream in distracted attempts to soothe our sadnesses. However, while an occasional hankering for sweet or starchy “comfort foods” is both normal and expected, for some, the link between negative feelings and out of control eating is far more profound. Recent studies suggest that the suspicious overlap in symptoms of major depression and food addiction may be due to deep biochemical connections that have gone largely ignored in treatment programs until now.

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The coexistence of psychiatric diagnoses and problems with appetite is shocking common. One research study concluded that approximately 80 percent of patients with binge eating disorder (BED) and 95 percent of patients with bulimia met the criteria for at least one other diagnosis outlined in the Diagnostic and Statistical Manual of Mental Disorders. Overweight men and women are 25 percent more likely to suffer from mood disorders than the rest of the population. Between 15 percent and 40 percent of patients with eating disorders also struggle with substance abuse.

Strikingly, 75 percent of patients with eating disorders also suffer from depression. For those individuals with binge eating disorder who are overweight, one study found that rates of depression are even higher than for individuals who are overweight but do not have binge eating disorder. In this particular study, researchers found that symptoms of depression led to binge eating episodes. Other studies have found that depressive symptoms, including low self-esteem, predicted increases in binge eating, demonstrating further evidence of the relationship between depression and binge eating. These results suggest that for some binge eating is a way to regulate emotion, however they also reveal that there is something more to the association between food addiction and depression than previously thoughtsomething disruptive, persistent, and physiological.

A look into the intricate neurochemical underpinnings of depression and binge eating disorder provides a clearer understanding of the biological nature of their troubling comorbidity. Interestingly, depression and food addiction both involve alterations in neurotransmitters, the substances that relay messages from one brain cell to another and then to the rest of the body. We know that imbalances in any of the neurotransmitters can wreak havoc with brain circuitry and predispose individuals to mental and physical distress. Normal levels of serotonin, the neurotransmitter linked most closely to satisfaction, lead both to emotional satisfaction and a sense of fullness after a meal. Low levels, on the other hand, can lead to depression and a tendency to binge on sweet and starchy foods. In fact, one study looking at how depression and a gene associated with lower levels of serotonin related to binge eating found that depressed children and older females who carried this gene were more likely to engage in binge eating behaviors.

In the context of a biochemical perspective on binge eating, this correlation makes sense. For some binge eating foods begins as a way to find a moment of much needed relief from depressive tendencies, and to fill the emotional void left by a lack of serotonin. However, what begins as a seemingly innocent attempt to self-soothe, quickly gives way to a complex cycle of addiction in the body. The flood of endorphins from eating large amounts of food only temporarily alters the neurochemistry of the brain, providing brief periods of solace from emotional distress; but these are not lasting. Ultimately, the demand for food intake to achieve such pacifying effects only increases over time and the coping mechanism completely fails, exacerbating instabilities with mood.

More research is needed to examine the precise mechanisms by which a serotonin deficiency can affect food, appetite, weight gain, and mood, and the causal nature of this overlap. However it is evident from the current body of scientific literature, that a holistic approach to investigating the interplay between an individual’s relationship to food and co-existing mood disorders is essential in order for successful recovery opportunities to exist. Treating one problem in isolation is not enough. It is only by comprehensively assessing the neurochemical commonalities underlying such complex psychological conditions that sustainable treatment solutions become possible.

By Stephen B. Jones, M.D., psychiatrist.

The Scientific Reasons Why You’re Feeling Depressed

Are you waking up just feeling “blah”?  Like you don’t want to do anything except lie like a couch potato and watch TV, and even that is unsatisfying?  You not only feel low energy, but kind of miserable.  Perhaps you’re mad at yourself for not getting the house cleaned or not getting your work done and papers filed. Perhaps you’re feeling a bit lonely, left out by friends or unsupported by family.  You may dwell on mounting bills or the fact that you’re 10 or 20 pounds overweight.  You may feel aches and pains in your neck or back.  Or you may just may feel grouchy and want to remain undisturbed by life’s demands and conversational opportunities.  You may compare yourself unfavorably to your friend, roommate, cousin, or neighbor, who always seems to be on time, well-groomed, and on track to meet her goals.  We all have those “blah” days, but why do they happen and what can we do about them?

Brain Chemicals

The human brain

Some of us have brains that are more sensitive to the effects of stress. Researchers are just beginning to uncover the biochemistry behind this differential.  The most common forms of antidepressants target the neurotransmitters serotonin and norepinephrine because research shows that low levels of these chemical motivators are part of what makes us depressed. However, only some people respond well to the most common forms of antidepressants, while others try drug after drug with no substantial mood improvement. A recent research study may reveal the reason why. A study published earlier this year in Proceedings of the National Academy of Sciences suggests that differences in the way our brain’s process a chemical called galanin makes some of us less resilient and able to bounce back after difficult experiences.

The Weather

winter day

Less sunshine during the winter months can give us the blues, and this effect is more pronounced for some people than others.  Researchers Keller and colleagues studied hundreds of people and found that during the spring, moods improved along with doing more outdoor activities. We are also more cognitively flexible and able to think creatively about solving our problems in the spring, compared to winter.  A subgroup of us suffer from Seasonal Affective Disorder in which the winter blues turn into full-blown depression along with associated changes in sleep, appetite, and motivation.  Sufferers are more likely to be women. Exposure to outdoor sunlight also provides us with vitamin D; a substance with clear links to depressed mood.

Vitamin D

vitamin D

Most people in the US have insufficient or deficient levels of Vitamin D. The reasons are not clear, but could be related to nutrition and insufficient sun exposure.  People with dark skin are more vulnerable to vitamin D deficiency, due to a decreased ability to process vitamin D from sunlight.  Vitamin D deficiency has been statistically linked to depression. In a large Dutch study by Hoogendijk and colleagues (2008) of over 1,200 persons aged 65 and older, levels of vitamin D were 14% lower in persons with minor depression or major depressive disorder when compared to those not showing depressed mood.

Hormones

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Hormones are substances produced by the endocrine glands that influence many bodily functions, including growth and development, mood, sexual function, and metabolism. Levels of certain hormones, such as those produced by the thyroid gland, can be factors in depression. In addition, some symptoms of depression are associated with thyroid conditions. Hormones fluctuate during the menstrual cycle and may create vulnerability to sad or depressed mood in the premenstrual period, as well as during peri-menopause, and menopause. There are individual differences in how much our moods are vulnerable to the effects of hormones.  If you are more vulnerable, you may want to consult a physician to see if medications are needed to help regulate your hormones. Or you could try alternative medicine treatments, such as acupuncture to reduce hormone-related mood imbalance.

Expectations

Expectations

Our moods are not only a function of what happens to us, but also of how we view the events in our lives and the meanings we assign to them.  There are stages in most of our lives in which we seem to be working hard and doing all the right things, but don’t see many external rewards coming our way.  We may not be paid what we feel we are worth or be able to afford as nice a house, car, or vacation as our friends.  We may struggle to find the right partner while our friends or siblings seem to have no problem finding love.  We may have to work longer and harder than our friends to get the same grade on a test or earn a living.  We may experience a difficult breakup or loss. Life just naturally isn’t fair and periods of struggle, suffering and loss are inevitable.  If we expect fair or special treatment all the time or expect things never to change, we are bound to be disappointed.  So if you’re feeling sad because of recent events, remind yourself that hard times are part of life and will pass.  Or deliberately broaden your view and focus on the good parts of your life or the experiences you are proud of.

Childhood Adverse Events

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Stressful life events can wear down our physical and mental resources, making us more vulnerable to both depression and physical illnesses.  A history of childhood trauma, including abuse, poverty, or loss of a parent, can reset our developing brains to be less cognitively flexible.  It seems that our brains naturally go into a “fight, flight, freeze” response to stress or threat and we often have to use our prefrontal cortex or executive center to get out of this state. Prolonged stress in childhood can make our brains less interconnected and resilient..  Our brains can more easily get “stuck” in negative thinking patterns or stressed out states and we become less able to change tracks.

Stresses Piling Up

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As Robert Sapolsky argues in his book Why Zebras Don’t Get Ulcers, our human stress response systems were designed to respond to acute, time-limited stressors that normally require a physical response.  When our ancestors had chased off that marauding tiger, they could relax and eat.  The stressors in today’s world are much more chronic and less controllable by taking action, and we often don’t get the break afterwards to recover and regroup. Financial stress, loneliness, constant fighting with loved ones, being bullied, long commutes, academic or job demands, or unemployment can drag on and have a cascade of effects across many areas of our lives.  When stresses hit us one after the other without time for recovery, they can leave us depleted and despondent, with insufficient pep to bounce back.

Negative Ruminations

rumination

You may be feeling bad because you’re sitting around brooding about life’s disappointments or trying to find a reason why things aren’t going your way.  Research studies by University of Michigan psychologist Susan Nolen-Hoeksema and colleagues show that sitting around thinking about your negative mood or negative events just makes everything worse!  One negative thought leads to another until you get buried in a mountain of problems and negative predictions. This leads to a loss of perspective and motivation that interferes with actually doing something about the problem! If you find yourself in a negative thinking cycle, get up immediately and do something else pleasant or neutral to engage your mind.  This can be as simple as emptying the dishwasher, rearranging your closet, going for a walk, talking to a friend or getting on with a work project.

Your Inner Critic

inner critic

Do you have a critical inner voice constantly judging and criticizing everything you do, especially when things don’t go your way? The inner critic compounds the effect of anything negative in your life by blaming you for it.  It keeps drawing your attention to the negative and spoils your pleasure when something positive happens by telling you ”it won’t last” or “you don’t deserve it”.  This negative dialogue takes you out of the moment and makes you feel depressed. Negative thinking is, at minimum, a symptom of depression, and may be a causal factor in interaction with negative life events. The first step to combat an inner critic is to become aware of what it’s saying.  Second step is to externalize it. You could give your critic  a name and imagine what it looks like (e.g., a grumpy old crone or a vicious barking dog). Then begin telling it to back off or talk back to it.  The inner critic generally has a negatively biased perspective and overestimates your responsibility for and control over outcomes in your life. It also often has perfectionistic expectations. Tell it to give you a break for a change!

Loneliness

lonelines

Our human brains are wired of be part of a social group, and we experience loneliness as chronically stressful and depressing. Unfortunately, some of us have toxic or neglectful families that don’t provide support or presence when we need it. Or we may feel that our friends are moving on in finding romantic relationships or having kids and leaving us behind. Research using fMRI brain scans shows that even minor social rejection lights up the same areas of our brains as physical pain. Feeling left out, rejected, or excluded makes us sad and can also lead to rumination about what is wrong with us that further darkens our moods.  We become scared of further rejection and isolate ourselves, perpetuating the negative cycle.  While there may not be a immediate cure for loneliness, it helps to get out in the world and pursue your natural interests, which can lead to expanding your social network. Staying in touch with old friends or family and deliberately seeking opportunities to connect may help as well.

Final Thoughts

The reasons for a down mood may be multifaceted and difficult to determine. If you feel depressed for two weeks or more, seek a medical consult to rule out or treat underlying biological factors. Consider consulting a mental health professional for help in managing stress and expectations, negotiating life changes, or dealing with the emotional aftereffects of past traumas and dysfunctional families. If you can’t afford therapy, antidepressants may help to change the underlying biology. Exercising outdoors can provide both sunlight and mood elevation. Develop a toolkit of stress-reducing activities, such as regular exercise, yoga or meditation, watching funny movies, playing team sports, doing something creative or novel, hanging out with and/or confiding in understanding friends.

 

By Melanie Goldberg, Ph.D.

Dr. Goldberg is a clinical psychologist with a private practice in Mill Valley, California.

 

 

Post-Prozac Nation

From The New York Times, an important new article which addresses what we now know about depression, antidepressants and serotonin.  Important read for anyone who takes medication.  Read the Story.

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