A 2004 meta-analysis of previous research showed that lithium was better than placebo at preventing affective episodes and preventing manic episodes. The evidence for the drug’s efficacy in preventing depression was less clear. A new meta-analysis by E. Severus et al. (not yet published) confirms the previous findings and provides new evidence that lithium is also better than placebo at preventing depressions.
The study also suggested that lithium is better than anticonvulsant mood stabilizers at preventing relapse and recurrence, but this finding only reached statistical significance in the prevention of new manic and hypomanic episodes.
Editor’s Note: These findings highlight the desirability of greater lithium use. The drug is currently prescribed less often in the US than it is in Europe. In addition to lithium’s efficacy in the long-term preventative treatment of bipolar disorder, there is evidence that lithium is also the best agent for suicide prevention and for neuroprotective effects.
There is increasing evidence of a link between mood disorders and inflammation in the body.
At the 2014 meeting of the International Society for Bipolar Disorders, Shang-Ying Tsai discussed increases in measures of inflammation that occur in bipolar disorder as a function of the clinical state of depression, mania, or euthymia (remission). He found that in both mania and depression, there were elevations in various markers of inflammation: STNF-R1, CRP, IL-Ira and SLR-2r. However, SLR-2r showed some particularly interesting results. In mania, elevation of SLR-2r, a marker of cell-mediated inflammation, was state-related, meaning it increased during an episode of mania and remained normal during euthymia. In depression, SLR-2r elevation was trait-related, or persistently elevated (even in remission).
Editor’s Note: This study adds to a growing list of studies that confirm the presence of inflammation in patients with bipolar disorder compared to normal controls, including a 2012 article by Tsai in the Journal of Affective Disorders. How elevations in inflammatory markers in a given individual should direct specific types of treatment intervention remains to be further clarified.
The Pittsburgh Bipolar Offspring study, led by Boris Birmaher of the University of Pittsburgh, investigated risk of illness in the offspring of parents with bipolar disorder. The study included 233 parents with bipolar disorder and 143 controls. In addition to bipolar disorder, parents in the study had many other disorders, including anxiety (70%), panic (40%), a disruptive behavior disorder (35%), attention-deficit hyperactivity disorder or ADHD (25%), and substance use disorder (35%).
The offspring averaged age 12 at entry in the study. Offspring of parents with bipolar disorder had more illness than those of control parents, including bipolar spectrum disorders (10.6% versus 0.8%), depression (10.6% versus 3.6%), anxiety disorder (25.8% versus 10.8%), oppositional defiant disorder or conduct disorder (19.1% versus 8.0%), and ADHD (24.5% versus 6.7%). Of these differences, only bipolar spectrum disorders and anxiety were statistically significant after correcting for differences in the parents’ other diagnoses.
Two factors predicted bipolar spectrum disorders in the offspring: younger age of a parent at birth of child and bipolar disorder in both parents. Older children and those with diagnoses of anxiety or oppositional defiant disorder were more likely to be diagnosed with bipolar disorder.
On long-term follow-up that continued on average until the offspring reached age 20, 23% of those participants who had a parent with bipolar disorder developed any type of bipolar disorder, versus only 1.2% of the children of controls. Of these 23%, about two-thirds had a depressive episode prior to the onset of their bipolar disorder.
Of the offspring of parents with bipolar disorder who developed a bipolar spectrum illness, 12.3% developed bipolar I or II disorders, while 10.7% were diagnosed with bipolar not otherwise specified (NOS). Of those with bipolar NOS, which some consider to be sub-threshold bipolar disorder, about 45% converted to a bipolar I or II diagnosis after several years of prospective follow-up. These data, along with the finding that children with bipolar NOS are highly impaired and take more than a year on average to remit, stress the importance of vigorously treating this subtype, even if it does not meet the full threshold for bipolar I or bipolar II.
Birmaher indicated that although about 50% of the offspring of a bipolar patient had no diagnosis, the high incidence of multiple psychiatric difficulties developing over childhood and adolescence spoke to the importance of attempts at early intervention and prevention. Studies of effective treatment and prevention strategies are desperately needed. So far only family focused therapy (FFT), an intervention developed by researcher David Miklowitz, has shown significant benefits over standard treatment in children with a positive family history of bipolar disorder who already have a diagnosis of anxiety, depression, or bipolar not otherwise specified.
In a six-week study published by S.S. Qu et al. in the Journal of Psychiatric Research in 2013, participants with depression who received manual or electrical acupuncture along with the selective serotonin reuptake inhibitor (SSRI) antidepressant paroxetine (Paxil) improved more than those participants taking paroxetine alone.
More patients taking paroxetine alone needed increased doses to deal with symptom aggravation.
Patients who had received electrical acupuncture continued to show improvement four weeks after the treatment ended.
Intravenous scopolamine has shown promise as a rapid-acting antidepressant in studies by Carlos Zarate and colleagues at the National Institute of Mental Health (NIMH). Improvement on the drug can occur within 24 hours.
In a 6-week 2012 study, an oral preparation of scopolamine was more effective than placebo as an add-on medication to the selective serotonin reuptake intake (SSRI) antidepressant citalopram. Patients who received scopolamine and citalopram had higher rates of response and remission than those who received placebo and citalopram. The scopolamine group experienced more blurred vision and dizziness, which is to be expected from an anticholinergic drug, a drug that blocks the action of the neurotransmitter acetylcholine in the brain.
Not every treatment for mood disorders works for every patient, and for the 60% of depressed patients whose first treatment is ineffective, this wrong guess can translate into months of suffering, wasted money, lost productivity, and risk of suicide. An important trend in treatment research is the search for biomarkers, that is, biological indicators that can predict which patients might be likely (or unlikely) to respond to a particular treatment. A 2013 study by McGrath et al. in the journal JAMA Psychiatry suggests that brain glucose metabolism is one such biomarker.
Patients with untreated major depressive disorder had their brain glucose metabolism measured and then were randomized to receive 12 weeks of treatment either with the SSRI antidepressant escitalopram oxalate (trade name Lexapro) or with cognitive behavior therapy. Low glucose metabolism in a part of the brain called the anterior insula (compared to the rest of the brain) predicted that patients would reach remission on cognitive behavior therapy and respond poorly to escitalopram, while high metabolism in the same area predicted the opposite, that patients would reach remission while taking escitalopram and respond poorly to cognitive behavior therapy.
Researchers will want to test this finding with patients over the long term, but the data from this study suggest that anterior insula glucose metabolism may be a successful biomarker that can guide initial treatment selection for patients with depression.
Cultures where more omega-3 fatty acids (which have anti-inflammatory effects) and fewer omega-6 fatty acids (which have pro-inflammatory effects) are consumed have a lower incidence of depression and bipolar disorder. However, the exact role that each kind of fatty acid plays in the brain and whether dietary changes can improve mood disorders is still being investigated. A 2012 study in the Journal of Psychiatric Research examined the complete lipid profiles of participants with bipolar disorder to collect data on these questions.
The most significant results to come from the study were that levels of the long-chain omega-6 fatty acid dihomo-gamma-linolenic acid (DGLA) were positively correlated with neuroticism, depression severity, and decreased functioning. Depression severity was negatively correlated with the omega-6 fatty acid linolenic acid (LA) and the omega-3 fatty acid alpha-linolenic acid (ALA), and positively correlated with fatty acid desaturase 2 (FADS2), an enzyme that converts LA to the omega-6 fatty acid gamma-linolenic acid GLA.
The data suggest that particular omega-6 fatty acids and the enzymes that lead to their production may be used as biomarkers that can indicate depression.
Editor’s Note: Levels of specific omega-6 fatty acids and their related enzymes were found to correlate with depression severity in this study. Since omega-6 fatty acids are pro-inflammatory, diets higher in omega-6 fatty acids are associated with more cardiovascular problems, and a 2012 article by Chang et al. in the Journal of Psychiatric Research reported that completed suicides in bipolar patients with cardiovascular disorders were significantly higher than in those with bipolar disorder without cardiovascular illness, it seems a healthy diet can have multiple benefits, including potentially reducing depressive burden, cardiovascular risk, and suicide risk.
Iron deficiency is the most prevalent nutritional deficiency in industrialized countries and can cause problems with cognitive and intellectual development. New research published in the journal BMC Psychiatry shows that it has psychiatric ramifications as well. Children and adolescents with iron deficiency anemia are at greater risk for psychiatric disorders, including depression, bipolar disorder, anxiety, and autism.
Iron supplementation should be implemented in children with iron deficiency anemia in order to prevent any possible psychiatric repercussions, and similarly, psychiatrists should check iron levels in young patients with psychiatric disorders.
Iron provides myelin for white matter in the brain and plays a role in the function of neurotransmitters.
In a recent study by Ghasemi et al. published in the journal Psychiatric Research, 18 patients with unipolar depression were divided into two groups, one that received intravenous infusions of ketamine hydrochloride (0.5 mg/kg over 45 minutes) three times (every 48 hours), and another that received electroconvulsive therapy (ECT) on the same schedule.
Ketamine produced antidepressant effects more quickly than ECT, and these effects were significantly better than baseline for the duration of the study, but not significantly different from those achieved through ECT by the end of the study.
Editors Note: These data continue to add to the already strong findings that ketamine produces rapid-onset antidepressant effects. When and where ketamine should be incorporated into routine clinical treatment of depression remains to be further clarified.
There is mounting evidence that inflammation and metabolic problems are related to depression. A recent study by Vogelzangs et al. in the journal Neuropsychopharmacology examined 313 patients being treated for depression to see whether levels of inflammatory markers in the blood and metabolic factors such as cholesterol, blood pressure, and waist circumference predicted whether those patients would still (or again) be diagnosable with depression two years later.
Several factors predicted later depression, including high levels of the inflammatory marker interleukin-6, low HDL (“good”) cholesterol, higher than normal triglycerides, and high blood glucose (hyperglycemia).
People who had four or more types of inflammatory or metabolic abnormalities had almost twice the odds of having chronic depression. Among those study participants who had only recently begun taking antidepressant medication, having four or more of these risk factors made them almost 7 times more likely to be depressed during follow-up.
One explanation for the connection between inflammatory and metabolic dysregulation and depression is that inflammation and metabolic problems worsen and complicate a patient’s depression and reduce the patient’s responsiveness to traditional antidepressants. Alternative ways of treating these patients aimed at their inflammation and metabolism may be necessary.