New guidelines to focus on mixed features in depression, bipolar

“Lurasidone does not have the metabolic changes of quetiapine. It doesn’t make sense to treat mania and then erase 25 years of a person’s life because of weight gain,” Dr. McIntyre said.

The average lifespan of people with bipolar disorder is about 20 years shorter than it is for those without serious mental illness.

Inflammation harms cognition

The changes are indicative of how seriously the field has begun to take metabolic disturbance as an adverse event in serious mental illness. Literature on obesity as a “psycho-toxin” is growing, and Dr. McIntyre is among the pioneers.

One study by Dr. McIntyre and his colleagues, currently in press, explores how obesity-related inflammation disturbs the brain’s dopamine system, resulting in interference with executive function. Because it is well established that people with bipolar disorder are more likely to be obese (J Affect Disord. 2008 Sep;110[1-2]:149-55), they also are more susceptible to cognitive impairment than are people of normal weight, according to Dr. McIntyre.

In a 2013 study, Dr. McIntyre and his colleagues showed that a first episode of mania in a person with obesity creates the same level of cognitive impairment as that found in the brains of normal-weight individuals who have experienced five episodes of mania (Psychological Med. 2014 Feb;44[3]:533-41). “There is something about obesity that is brain toxic,” he said.

Proof of concept of this is that cognitive outcomes for people before bariatric surgery are worse than postsurgery outcomes (Am J Surg. 2014 Jun;207[6]:870-6).

Systemic inflammation elevates levels of C-reactive protein, interleukin-1, and other cytokines, and interferes with insulin signaling; all have deleterious effects on cognition, as well as metabolic health. Those disturbances negatively affect emotional regulation, sleep, appetite, and sex drive, as well as executive function, he said.

“Inflammation is a convergent system, implicated across many brain- and body-based disorders. People with bipolar disorder not only have systemic increases in inflammation, but also neuroinflammation,” Dr. McIntyre said.

Accordingly, controlling inflammation becomes essential to chronic management of depression in general and bipolar in particular since, with each successive episode of untreated mania, patients’ ability to think clearly takes a hit. “Cognitive function is the principal determinant of psychosocial function, of workplace visibility, [and] of quality of life in most patient-reported outcomes,” Dr. McIntyre said.

Cognitive impairment also can lead to a worsening of the ability to balance reward and impulse control, leading to higher rates of substance abuse or other psychiatric comorbidities after onset of bipolar disease; a vicious cycle can ensue.

“As cognitive difficulties rise, comorbidities rise. But also, some of the comorbidities we see are reflections of cognitive impairment,” Dr. McIntyre said. To wit, binge eating disorder and bulimia nervosa are common in people with bipolar disorder (J Affect Disord. 2016 Feb;191:216-2).

Citing a recent scientific statement from the American Heart Association recommending that bipolar disorder and MDD should be considered tier II risk factors for cardiovascular disease among youth, the Florida guidelines urge clinicians to regularly screen patients for cardiometabolic disorders – not only for their medical implications but for their potential to flag emergent psychiatric issues.

Pharmacotherapeutics specifically targeting neuroinflammation are not yet ready for clinical practice, but Dr. McIntyre said other, more conventional therapies are available for bipolar disorder that have anti-inflammatory properties, including selective serotonin reuptake inhibitors and lithium. “Lithium is also anti-amyloid and has an anti-suicide effect. It is a drug I would definitely use as first line.”

Some behavioral therapies also are protective against inflammation and are recommended in the guidelines. Those include attention to sleep hygiene, diet, and exercise. “Social rhythm therapy is underutilized. These patients need their day organized. They need aerobics; they need sleep,” Dr. McIntyre said.

Future is now

Although the “whole-person” approach is still nascent – seeing depression as a collection of what Dr. McIntyre said are alterations in the neural circuitry amounting to a series of “disconnection syndromes” – psychiatry already has entered a new era where disease models are more comprehensive, he said.

This new way of thinking can connect the dots between why, for example, so many people with bipolar depression also have drug and alcohol abuse. It also could help explain why in bipolar there is so much obesity, or why there is so much anxiety, he said. “We’ve moved away from the rather silly, overly simplistic notions that you have too much or too little serotonin. Or that there was too much or too little dopamine causing mania. It made for convenient sound bytes, but it was probably just superstition we were gravitating to.”