February 3, 2012 — A "complex interplay" of neurobiological, psychological, and socioeconomic factors contribute to the dangerous association between obesity and mental illness, according to 2 clinical reviews published in the January issue of the Canadian Journal of Psychiatry.

In the first article, investigators discuss in detail how these factors relate to specific disorders, and how understanding better the mechanisms involved can help in choosing the most effective, patient-specific interventions possible. The second article provides an overview of current treatment options.

"This is a serious issue. And we're not helping our patients at all if we don't really understand these links," lead author Valerie H. Taylor, MD, PhD, associate professor at the University of Toronto and psychiatrist-in-chief at Women's College Hospital in Toronto, told Medscape Medical News.

Dr. Valerie Taylor

She noted that clinicians, including psychiatrists, family physicians, and endocrinologists, need to work as a team to treat these patients.

"We need to apply rational therapy and make sure we don't make 1 illness worse when we're treating another," said Dr. Taylor.

"We also need to be aware that the only illness perhaps more stigmatizing than mental illness is obesity. So when you have a population that has both, realize that that's a group that is going to be really vulnerable and at risk."

Meds Only One Contributing Factor

"Obesity is associated with early mortality and has overtaken smoking as the health problem with the greatest impact on quality of life, mortality, and morbidity," write the researchers.

They note that although many public health initiatives have focused on the importance of weight loss, there continues to be a significant rise in the rates of obesity — in part because most of these initiatives fail to recognize underlying factors, which can include mental illness.

The investigators add that although use of atypical antipsychotics, antidepressants, and mood stabilizers often results in weight gain, this only accounts for part of the link between psychiatric illness and obesity and associated comorbidities such as hypertension, cardiovascular disease, and diabetes.

In the first review article, the investigators highlight symptoms, challenges, and underlying mechanisms for several psychiatric disorders, according to recent studies. These include the following:

Major depressive disorder (MDD) and bipolar disorder symptoms often disrupt appetite, motivation, energy, and sleep.

Depression is also often associated with smoking and drinking, dopaminergic deficits, an increase in cortisol levels, lower grades of inflammation, and abnormal levels of leptin and adiponectin.

Schizophrenia is associated with increased risk for cardiovascular disease and possibly with increased glucose dysregulation, hypodopaminergic activity, and comorbid MDD.

Patients with attention-deficit/hyperactivity disorder (ADHD) often have difficulties focusing on preparing healthy meals, have impulsivity issues leading to overeating, and have an inability to delay reward-seeking behaviors.

Children with ADHD have been found to have poorer physical activity, motor performance, and motor development than their healthy peers.

Both sexual and physical abuse have been associated with increased body mass index and waist circumference in adults, possibly as a result of an increase in levels of cortisol, which is a stress hormone.

The investigators note that most common and chronic mental illnesses are also often associated with unemployment and low socioeconomic status, leading to being uninsured and unable to access medical technology and tertiary clinics.

"While having a psychiatric illness does not make weight gain inevitable, it does often require that additional tools be added to lifestyle recommendations around diet and exercise," the investigators write.

Weight Loss Rx Largely Unregulated

Dr. Taylor said that the treatment of weight problems in both Canada and in the United States is virtually unregulated.

"It's really akin to the snake oil salesmen of 60 years ago. We have a vulnerable population that is desperate because they need treatment for their mental illness, but they're gaining lots of weight and developing other physical health problems. So they're going and spending huge amounts of money on what are essentially scams that are perpetuated in the media," she said.

"We wanted to apply an evidence base to better understand how to treat these problems when they come up, especially because there are a lot of urban myths out there."

She cautioned against programs that promote radical weight loss or that emphasize significant physical activity without corresponding changes in diet. She also said to be aware of many herbal products available over-the-counter or over the Internet, which can contain stimulants and other substances.

The various clinical approaches to weight management reviewed and considered potentially helpful in the second article include the following:

Cognitive-behavioral therapy, especially for depressive disorders and binge eating disorder;

Mindfulness-based stress reduction;

Dialectical behavioral therapy, which focuses on introducing affect recognition and regulation skills;

Interpersonal psychotherapy, which addresses social deficits; and

Motivational interviewing, which focuses on resolving ambivalence.

The authors also discuss anti-obesity pharmacotherapy, which they admit is "fraught with controversy," and bariatric surgery.

"It is important that health professionals involved in the care of people with a mental illness become familiar with the interventions available to control and treat the obesity epidemic, as this will improve treatment compliance and ultimately lead to improved physical and psychological outcomes," write the investigators.

"We also need to be aware of the role of weight bias, as this population is often subject to prejudice and discrimination, and treatment of any type may need to incorporate tools to alleviate feelings of rejection and guilt."

"Nobody expects psychiatrists to manage cardiovascular illness and diabetes," said Dr. Taylor. "But we do expect them to understand these are risks for their patients. So they need to contact and form a relationship with other healthcare providers. Then we take care of our piece and they take care of theirs to provide the best care for patients."

Mental Health Must Be Considered

In an accompanying editorial, Arya M. Sharma, MD, PhD, professor of medicine and chair of the Obesity Research and Management Program at the University of Alberta in Edmonton, Canada, writes that the reviews' findings correlate with a proposal he published last year, which stated that "even a cursory assessment of mental health should be an integral part of every assessment for obesity."

Dr. Arya Sharma

"In addition, mental illness must be considered as a possible etiological factor in anyone presenting with weight gain attributable to overeating and under-moving," writes Dr. Sharma, who is also scientific director of the Canadian Obesity Network.

He adds that it is just as important for mental health practitioners to familiarize themselves with obesity treatments as it is for those managing obesity to have "at least basic competencies" in assessing mental health.

"The link between obesity and mental health is an issue that I don't think has been discussed enough," Dr. Sharma told Medscape Medical News.

He noted that in an editorial published in 2010 in Obesity Reviews, he wrote about the four M's that should always be considered when assessing obesity: mental, mechanical (such as excess body size or musculoskeletal disorders), metabolic, and monetary problems.

"Any of these could be barriers to treatment, but the very first one is mental health. It is often virtually impossible for a person with mental illness to properly manage their weight because it involves a lot of factors that they cannot control," he said.

"I don't think we'll find a solution to the obesity epidemic without facing the mental health epidemic. And I think all of these articles highlight that relationship."

Dr. Sharma noted that this has become such an important issue that the Canadian Obesity Network, in partnership with the International Association for the Study of Obesity and the Center for Addiction and Mental Health, is hosting a "Hot Topic Conference" on obesity and mental health, to be held June 26-28 in Toronto.

"To my knowledge, this will be the first international symposium on this topic ever," he reported.

Honorarium from the Canadian Psychiatric Association is provided to all authors of articles published in the Canadian Journal of Psychiatry "In Review" series. The study authors and Dr. Sharma have disclosed no relevant financial relationships.

Can J Psychiatry. 2012;57:3-4,5-12,13-20. Abstracts