Links between obesity and mental health
Negative feelings fuel depression, and people often use food to self-medicate.
At a glance
- Rather than focus on the end result of obesity, look at the patient's underlying emotional health.
- Studies have found depression to correlate with the onset of obesity and obesity to predict the onset of depression.
- If you suspect an overweight patient is struggling with a mental health issue, approach the possibility directly.
- Obesity prevention is a public health issue because of the costs it creates for an already overburdened system.
Seventy-three million Americans are obese —a startling statistic that becomes more than a number in our day-to-day clinical lives as we treat patients suffering from the sequelae of this epidemic: gastroesophageal reflux disorder, diabetes, hypertension, polycystic ovary syndrome, infertility, gallbladder disease, osteoarthritis, and hyperlipidemia. Primary-care practitioners should be aware of a potential underlying cause of obesity: mental illness.
Recent studies have shown that many cases of obesity are the result of such mental illnesses as depression, anxiety, post-traumatic stress disorder (PTSD), binge eating disorder, and night eating syndrome. In a busy clinic it's difficult even to begin to unearth and address these factors when the purpose of the patient's appointment is chronic illness management. However, instead of focusing on the end result of obesity, we may be of greater assistance to our patients by looking at their underlying emotional health and intervening as appropriate.
Understanding the mental health/obesity relationship
What part does mental health play in the rise in obesity seen over the past 20 years? "We have more emotional issues than ever to deal with," explains Phillip Ballard, MD, a family practice physician and psychiatrist with Colorado Springs Health Partners (CSHP) in Colorado Springs, Colorado. "We have more than any other society has and we feel guilty that we're not happy." According to Dr. Ballard, these negative feelings fuel depression, and people often use food to self-medicate their emotions. Food is seen as nurturing; consider how we frequently turn to our "comfort foods" that remind us of feeling happy or cared for.
People are living longer than ever before, and paradoxically, that brings more problems. For example, Dr. Ballard points out, older, retired individuals who are prone to anxiety and depression have lost a tool for relieving these conditions. "Work has always been used to control anxiety and depression," he notes.
Family dynamics and stress play an integral role in mental health. Extended families are not as geographically close today as in the past. Adult children are leaving home later, and their greater dependence on their parents contributes to more problems for everybody involved.
Lisa M. Schab, MSW, LCSW, a Chicago-based licensed clinical social worker and author of several books on teen depression and anxiety, observes that in her practice, these two illnesses are the most common emotional health issues connected with obesity. Anxious patients can be compulsive, and eating compulsively and excessively contributes to obesity—making the behavior very destructive. In major depressive disorder, a common symptom is appetite change: A depressed person's appetite can increase or decrease, although an increase is more typical. Depression can lead to reduced physical activity, which has "always proved to work as well as psychotropics to control depression," states CSHP's Dr. Ballard.
Studies have found depression to correlate with the onset of obesity and obesity to predict the onset of depression. Depression predicts poorer success with weight loss, but successful weight loss is associated with a reduction in depression.
In addition to anxiety and depression, a recent study by indicated a strong relationship between PTSD and obesity, with a 32.6% rate of obesity found among PTSD patients (Obesity. 2009;17:539-544).
Women with less-than-positive emotional health are reported to have a significantly greater risk of weight gain (Obesity. 2008;16[Suppl 1]:s95). Michele Bartels, MSW, LCSW, a psychotherapist in private practice in Colorado Springs, says that many of her severely obese female patients have a history of sexual trauma in childhood. "They believe their weight protects them as a shield or a defense against others."
Interestingly, no heightened risk of obesity has been reported in persons with substance abuse disorders, perhaps because these individuals use agents other than food in their self-medicating behavior.
An elevation of cortisol levels reflects the clinical impression that night eating occurs during times of stress. Some obese patients describe having little to no hunger for breakfast. This may be a sign that they're overeating at night, as night eating syndrome is characterized by an unusual circadian pattern: minimal eating in the morning with hyperphagia (consumption of at least 25% of daily calories after supper) both during the evening and at night, along with insomnia. These patients often consume half their daily calories during these nocturnal eating episodes. Night eating syndrome was found to be unique in that it represents the coexistence of an eating disorder, a sleep disorder, and a mood disorder (Int J Obes Relat Metab Disord. 2003;27:1-12). The syndrome has been associated with an increased risk of dental caries, which can be assessed on an oral exam.
Binge eating disorder generally appears to be more common than the well-established eating disorders bulimia nervosa and anorexia nervosa. It is likely a chronic, albeit stable, disorder rather than a transient abnormal eating pattern.
In one study, participants with a current Axis I disorder as categorized in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition had a significantly higher BMI than those without such a diagnosis (Am J Psychiatry. 2007;164:328-334). In addition, even those study participants who had a history of any Axis I disorder had a higher BMI.