Meta-Analysis Shows Inflammation is Common in Unipolar Depression, Bipolar Depression, and Schizophrenia
In a symposium at the 2016 meeting of the Society of Biological Psychiatry, Mark Hyman Rapaport described the results of his research group’s meta-analysis of studies comparing levels of inflammation in the blood of people with unipolar depression, bipolar depression, and schizophrenia. Rapaport and colleagues determined that people acutely ill with any of the three illnesses showed abnormally high levels of certain inflammatory proteins. These included: interleukin-1beta, interleukin-6, TNF alpha, and c-reactive protein. Those who were chronically ill showed elevations in interleukin-6.
These data are consistent with increasing evidence that inflammation also occurs in the brain. Brain inflammation can be observed by measuring translocator protein binding, a measure of brain microglial activation, using positron emission tomography (PET) scans.
Bipolar disorder has been linked to cardiovascular disease. New research by Jessica Hatch and colleagues shows that inflammation may be at the root of this connection. At the 2016 meeting of the Society of Biological Psychiatry, the researchers showed that teens with bipolar disorder have higher levels of inflammatory marker interleukin 6.
Hatch and colleagues assessed the blood of 60 teens with bipolar I or II disorder and 20 healthy controls for a variety of biomarkers, including the inflammatory proteins interleukin 6, interleukin 10, and TNF alpha; VEGF, which is responsible for the production of new blood vessels; and brain-derived neurotrophic factor (BDNF), which protects neurons. The researchers also assessed the participants’ cardiovascular health, performing the carotid intima media thickness test to estimate how much plaque is in the arteries, and measuring how well the patients’ arteries dilate in response to changes in bloodflow.
Participants with bipolar disorder had higher levels of interleukin 6 than healthy controls, regardless of whether their bipolar illness was symptomatic. Low BDNF was linked to greater carotid intima thickness in participants with symptomatic bipolar disorder, and vascular measurements suggest a possible mechanism by which bipolar disorder increases cardiovascular risk.
At the 2016 meeting of the Society of Biological Psychiatry, researcher Femke Lamers and colleagues presented findings from the Netherlands Study of Depression and Anxiety. The inflammatory markers interleukin-6 and CRP were elevated in people with current major depression. These measures were correlated with BMI, a measure of body weight. High levels of interleukin-6 at the beginning of the study predicted who would have a chronic course of illness.
Editor’s Note: Previous studies have found that elevated levels of CRP predicted a future mood episode in people at high risk for bipolar disorder due to a family history of the illness.
These studies suggest that it might be useful to assess levels of these inflammatory markers (CRP, interleukin-1, interleukin-6, and TNF-alpha) in young people who are at high risk for bipolar disorder. Factors that put someone at high risk include a family history of depression or bipolar disorder, a history of adversity in childhood (abuse, neglect, loss of a parent, etc.), and preliminary symptoms.
Several interventions are available that may reduce the likelihood that someone at risk for bipolar disorder will go on to develop the illness. Family interventions such as the Family Focused Therapy developed by researcher David Miklowitz are helpful. In a 2013 study in the Journal of the American Academy of Child and Adolescent Psychiatry, Miklowitz reported that Family Focused Therapy outperformed treatment as usual for youth at risk for bipolar disorder.
Measures of inflammation might provide additional rationale for beginning interventions in youth at high risk for mood disorders. In addition to family interventions, omega-3 fatty acid supplementation is a low-risk option that is supported by some positive data. Since BMI was implicated in the study by Lamers and colleagues, keeping weight under control might also have some benefit.
For adults with depression who want to keep their weight under control, the combination of the antidepressant bupropion XR (150–300mg/day) and naltrexone (50mg/day), an opiate antagonist medication normally used to fight addictions, has been effective.
In a recent study by researcher Dan V. Iosifescu and colleagues, the drug galantamine, which is used to treat dementia, did not improve cognitive function in euthymic people with bipolar disorder. The drug had done so in earlier studies. Seventy-two participants with bipolar disorder that was in remission were randomized to receive either a placebo or galantamine extended release for a period of two weeks. Doses of galantamine ranged from 8 to 24 mg/day.
The participants took several tests of attention and memory over the course of the study. After 16 weeks of treatment, those taking galantamine did not show significant improvements in functioning compared to those who received placebo.
This research was presented at the 2016 meeting of the Society of Biological Psychiatry.
Depression and Bipolar Disorder in Adolescence Linked to Early-Onset Cardiovascular Disease and Hardening of the Arteries
The link between mood disorders and cardiovascular illnesses has been clear for some time. Now there is evidence that this link begins early in life. In 2015, the American Heart Association issued a statement that adolescents with major depressive disorder and bipolar disorder are at increased risk for both accelerated atherosclerosis (narrowing and hardening of the arteries) and early-onset cardiovascular disease.
In the statement, the American Heart Association recommended that major depressive disorder and bipolar disorder be classified as “tier II” conditions (which also include HIV and chronic inflammatory disease) that confer a moderate risk of disease.
Until recently, it had been assumed that the increased risk of cardiovascular disease among people with depression or bipolar disorder was a result of behaviors linked to these illnesses, such as higher rates of smoking, obesity, or diabetes, which increases heart disease. Some psychiatric medication can also bring about risk factors for cardiovascular problems. It turns out that these types of factors could not fully explain the increased risk of atherosclerosis and cardiovascular disease among people who had depression or bipolar disorder in their teens.
It is not clear why depression and bipolar disorder make cardiovascular illness more likely, though it may be due to blood vessel damage resulting from inflammation or oxidative stress.
The American Heart Association recommends that pediatricians and cardiologists pay particular attention to this link by identifying and treating mental illness as early as possible and by making sure that their colleagues understand the role of mental illnesses in cardiovascular risk.
Researchers are looking for better ways of predicting whether children at risk for bipolar disorder will go on to develop the illness. A 2015 study by David Axelson and colleagues in the American Journal of Psychiatry reported that in the offspring of parents with bipolar disorder, diagnoses of sub-threshold mania, depression, and disruptive behavior disorders were associated with subsequent diagnosis of full-blown Bipolar I or Bipolar II disorders six to seven years later.
More recently, in an article by Danella M. Hafeman and colleagues in the American Journal of Psychiatry, the same group of investigators has examined how symptoms (rather than categorical diagnoses, as in the earlier study) predict the development of bipolar disorder. In children and adolescents at high risk for bipolar disorder (because they have a parent with the disorder) three types of symptoms were the best predictors of later bipolar disorder: anxiety/depression at the time participants entered the study, unstable mood or irritability both when entering the study and shortly before a bipolar diagnosis, and low-level manic symptoms observed shortly before diagnosis.
The earlier the age at which a parent was diagnosed with a mood disorder, the greater the risk that the offspring would also be diagnosed with bipolar disorder. Youth with all four risk factors (anxiety or depression, mood changes, low-level mania, and a parent who was diagnosed with a mood disorder at an early age) had a 49 percent chance of developing bipolar disorder, compared to a 2 percent chance among those without those risk factors.
Childhood onset of bipolar disorder and long delays until first treatment for depression or mania are both significant predictors of a poor outcome in adulthood compared to adult onsets and shorter delays to treatment. Read more
Studies have shown that therapy can be helpful for people with bipolar disorder. In a 2016 article in the British Journal of Psychiatry, researchers led by M. Oud described the findings of their systematic review of studies evaluating different types of therapy for bipolar disorder. The research team reviewed the findings of 55 randomized controlled trials of psychotherapeutic interventions that included a total of 6,010 adult participants with bipolar disorder. The team found moderate-quality evidence that psychological interventions reduced relapses following treatment, and that collaborative care reduced hospital admissions for adults with bipolar disorder. Oud and colleagues found lower-quality evidence that group interventions reduced depression relapses following treatment, and that family psychoeducation reduced symptoms of depression and mania.
The reseachers concluded that there is evidence that therapy can be helpful for people with bipolar disorder. Since some of the evidence was of low quality, more research is needed to identify the most effective therapies for different phases of bipolar disorder.
Editor’s Note: The data are clear that therapy is helpful. In particular, one approach worth emulating is that described in an article by Lars V. Kessing and colleagues in the British Journal of Psychiatry in 2013. They found that comprehensive care in an outpatient mood disorder clinic, which included psychotherapy, psychoeducation, mood monitoring, and drug treatment, reduced relapses significantly compared to treatment as usual.
The Course and Outcome of Bipolar Youth study, or COBY, has been collecting information on young people with bipolar disorder and tracking their symptoms into adulthood since 2000. A 2015 study by Benjamin I. Golstein in the Journal of Clinical Psychiatry analyzed COBY data, identifying links between higher than average levels of inflammatory markers measured in the blood and participants’ histories of illness and familial risk factors.
High levels of the inflammatory marker hsCRP were associated with longer duration of illness, substance use disorder, and family history of suicide attempts or completed suicides. High levels of TNF-alpha were linked to suicide attempts, self-injury behaviors, and family history of substance use disorders. IL-6 was also linked to family history of substance use disorders.
There were also links between inflammatory markers and participants’ symptoms over the 6 months leading up to the blood tests. Levels of the inflammatory marker TNF-alpha were linked to the percentage of weeks patients had psychotic symptoms. Levels of IL-6 were associated with percentage of weeks with subthreshold mood symptoms and also with any suicide attempt. Levels of HsCRP were linked to maximum severity of depressive symptoms.
It is possible that targeting the elevated levels of inflammatory markers with anti-inflammatory treatments could improve patients’ response to treatments, but this topic requires further study.
In the past decade, several studies have indicated that people with bipolar disorder have less ability to recognize the emotions expressed on people’s faces than do healthy controls. A 2013 meta-analysis by Cecilia Samamé and colleagues concluded that facial emotion recognition was deficient in people with bipolar disorder regardless of their current state. A 2011 quantitative review article by Christian G. Kohler and colleagues revealed that this difficulty distinguishing emotions is general, rather than specific to any one emotion.
A 2015 study by Esther Vierck and colleagues in the journal Psychiatry Research showed that both euthymic patients with bipolar disorder and their first-degree relatives without bipolar disorder performed worse on tests of emotion recognition than did normal controls. The findings in healthy relatives suggest that the deficit may be a familial risk factor for the development of bipolar disorder.
These deficits in facial emotion recognition have also been seen in 4 out of 5 studies of children with early-onset bipolar disorder, including those who are euthymic. 2008 studies by Melissa A. Brotman and colleagues showed that even children just at high risk for bipolar disorder due to a family history of the disorder had deficient emotion recognition.
This literature indicates that deficiencies in facial emotion recognition consistently accompany bipolar disorder and may also be a sign that a child or teenager is at risk for bipolar disorder. Since these deficits can create social and interpersonal difficulties, it may be useful to teach better emotion recognition skills to people with bipolar disorder or those at high risk for the illness.
N-acetylcysteine (NAC), an antioxidant available without a prescription in health food stores, has shown remarkable effectiveness when added to regular treatments for schizophrenia, bipolar disorder, and the substance abuse that often accompanies these illnesses.
A 2008 article by Michael Berk and colleagues in the journal Biological Psychiatry reported that compared to placebo, 2 grams/day of NAC reduced both positive symptoms of schizophrenia (hallucinations, delusions) and negative symptoms (social withdrawal, difficulty planning and problem-solving). A 2013 study by Mehdi Farokhnia found that 2 grams/day of NAC improved negative symptoms in 42 patients with schizophrenia. Two other studies found that NAC improved deficits in auditory sensory processing in people with schizophrenia.
NAC also improves symptoms of bipolar disorder. A 2008 study by Berk and a 2011 study by Pedro Vieira da Silva Magalhães showed that NAC improved bipolar depression, and a small 2013 study by Magalhães showed that it improved mania in 15 patients. After 24 weeks, 60% of those who took NAC were in remission, compared to 15% of those taking placebo.
NAC is also effective at reducing habitual behaviors such as substance abuse, which is common in patients with schizophrenia and bipolar disorder. Studies have shown that NAC can reduce patients’ use of marijuana, cocaine, alcohol, and nicotine. It is relatively safe with minimal side effects, and fights oxidative stress, which is also common in severe mental illness.
NAC comes in 500mg or 600mg capsules. Dosing typically begins with one capsule twice a day for a week, followed by two tablets twice a day thereafter. As with any recommendations in the BNN, these should not be acted on without guidance from a treating physician.