Shorts

Jule Klotter

Yoga, Breathing, and Depression

A combination of Iyengar yoga and controlled breathing (five breaths per minute) alleviates symptoms of major depressive disorder (MDD), according to a 2017 study led by Chris C. Streeter, MD. Both yoga and slow breathing increase heart rate variability (HRV), an indicator of parasympathetic tone. Low parasympathetic tone is found in people with MDD, and studies have shown correlations between increased HRV and improved mood. Iyengar yoga focuses on physical alignment while performing hatha yoga poses with the aid of blocks, straps, blankets, bolsters, and other props as needed. It was developed by B.K.S. Iyengar, who was among the first yoga practitioners to teach Westerners.

For this study, Streeter et al enrolled 32 participants, age 18-64, with a current diagnosis of MDD and a Beck Depression Inventory-II score ≥14. The patients were either not taking antidepressant medication or were on a stable dose for three or more months. The study compared two protocols in order to figure out the more effective number of yoga sessions to use for MDD in future studies. The high-dose group (HDG) had three 90-minute yoga classes and four 30-minute homework sessions per week. The low-dose group (LDG) took two 90-minute yoga classes with three 30-minute homework sessions per week. The classes consisted of yoga postures (60 minutes), deep relaxation in the savasana/corpse pose with ujjayi breathing (10 minutes), and coherent breathing (five breaths/minute with equal inhalations and exhalations) for the remaining 20 minutes. During ujjayi breathing, laryngeal muscles are slightly contracted and the glottis is partly closed, creating a slight resistance and activating vagal afferent nerves in the larynx and pharynx. The 30-minute homework assignments consisted of yoga poses (15 minutes) and coherent breathing using a CD for pacing (15 minutes).

After 12 weeks of treatment, the authors found no statistically significant difference in response (>50% reduction in BDI-II scores) or remission (BDI-II scores <14) rates between the two groups even though the HDG participants spent significantly more time in the yoga-breathing practice. However, more high-dose participants had BDI-II scores ≤10 at trial’s end: 93% of HDG (14/15) vs. 53% of LDG (8/15) (p=0.04).

Transient muscle soreness was the most common adverse effect. One participant reported having distressing thoughts during the coherent breathing exercise at home. Replacing the breathing component of the homework with an additional 15 minutes of yoga solved the problem. Participants in this study had a low risk of self-injury, so the results may not apply to patients with suicide ideation or more severe symptoms.

The main drawback, according to participants in the high-dose group, was the time commitment. “Considering the similar response and remission rates, the lighter schedule of the LDG may better balance effective intervention frequency with time demands,” say the authors. They also noted indications that the yoga intervention had a half-life of 48 hours, suggesting that two classes plus one homework session “might be sufficient to improve mood symptoms.”

The authors state that using yoga/breathing as an adjuvant treatment with an antidepressant appears to augment the medication’s effect and avoids drug-drug interactions and additional adverse effects, but larger studies involving patients on antidepressants are needed. The authors are conducting a larger trial with a walking comparison group.

Pizer A. The History and Practice of Iyengar Yoga. Updated April 26, 2017.

Streeter CC, et al. Treatment of Major Depressive Disorder with Iyengar Yoga and coherent Breathing: A Randomized Controlled Dosing Study. J Altern Comple Med. 2017;23(3):201-207.

Heart Rate Variability and Mental Health

Heart rate variability (HRV) is a marker for physical health and autonomic nervous system balance/imbalance; but it also correlates with mental well-being, according to a 2013 review by Andrew H. Kemp and Daniel S. Quintana. “HRV may be considered a marker of one’s capacity for self-regulation; social engagement and psychological flexibility,” say the authors. People with greater HRV are more likely to seek social support when dealing with stress and sadness. Increased HRV has also been associated with resilience, cheerfulness, calmness, and wellbeing. In contrast, reduced HRV, “reflecting a hypoactive parasympathetic (vagal) system,” negatively impacts mood, anxiety, and alcohol dependence. Low HRV has been observed in populations with attention deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, and other psychiatric disorders.

Kemp and Quintana have found that a decrease in resting-state HRV correlates to an increase in alcohol cravings in alcohol-dependent outpatients and to increased depression. They found that patients with depression who also had an anxiety disorder showed the greatest reductions in HRV, compared to those with depression alone.

All antidepressant medications, according to a meta-analysis that they performed in 2010 and other cited studies, decrease HRV (and increase the risk for cardiovascular disease). Non-medication interventions that improve HRV include cognitive behavioral therapy and slow breathing with prolonged exhalation. Slow breathing also decreased self-reported anxiety in musicians during stressful performances, according to the authors.

Kemp AH, Quintana DS. The relationship between mental and physical health: Insights from the study of heart rate variability. International Journal of Psychophysiology. 2013;89:288-296.

Electromagnetic Radiation and the Brain

It is an inconvenient truth in our smartphone, wireless society that electromagnetic radiation has multiple effects on the brain, including increased blood-brain permeability, neuron alterations, and increased lipid peroxidation. Almost 10 years ago, Henrietta Nittby and Swedish colleagues showed that two hours of exposure to radiation from a mobile phone (915 MHz) at non-thermal specific absorption rates (SAR) of 0.12mW/kg, 12 mW/kg, and 120 mW/kg caused albumin extravasation (leakage) in rats’ brains and albumin uptake into neurons that was still evident 14 days later. Although albumin extravasation and uptake were not present at day 28, significant neuronal damage was evident at 28 days and 50 days post-exposure.

In a normal brain, the blood brain barrier (BBB) maintains homeostasis by allowing water, most lipid-soluble molecules, oxygen, carbon dioxide, and limited amounts of sodium, potassium, and other ions to pass between the blood and nerve cells, according to Nittby et al. When the BBB is damaged and permeability increases, larger molecules, including proteins and toxic substances in the blood, come in contact with and damage brain cells. Normal BBB permeability is known to be disrupted in people with tumors, infarcts, infections, epileptic seizures, and severe hypertension.

In a 2017 study, Ju Hwan Kim and Korean colleagues showed that radiofrequency electromagnetic fields (RF-EMF), such as radiation emitted by cell phones, activate autophagy in cerebral cortex neurons and apoptosis in the brainstem cells of mice. Autophagy is a self-protective mechanism, activated by various stressors such as nutrient deficiency, during which injured organelles and unusual protein clusters are broken down and removed. According to Danielle Glick et al. autophagy also promotes cellular aging and protects against genome instability and necrosis, thereby preventing cancer and neurodegeneration.

Kim et al exposed mice to 835 MHz RF-EMF using a Wave Exposer V20 (SAR value of 4.0 W/kg for whole body exposure) or to sham treatment for five hours/day for four weeks. They used RT-PCR and Western blotting to look for autophagic and apoptotic changes in cerebral cortex and brainstem gene and protein levels. The researchers also used transmission electron microscopy to look for possible morphologic changes in cortical and brainstem neurons. After four weeks of RF-EMF exposure, evidence indicated that the autophagy pathway in the mice’s cerebral cortex, but not the brainstem, was activated. Signs of apoptosis, however, had increased in the brainstem and decreased in the cerebral cortex.

In 2014, Nidhi Saikhedkar and colleagues in India found that rats exposed to cell phone radiation (900 MHz) for four hours per day for 15 days displayed significant behavior changes (more anxiety and poor learning) compared to controls and to a sham control group. The exposed rats also showed significant changes in antioxidant enzyme levels, non-enzymatic antioxidant levels, and increased lipid peroxidation. Histological examination revealed neurodegeneration in the hippocampus and the cerebral cortex.

The Federal Trade Commission (FCC) regulations regarding cell phone and WiFi safety are based on thermal exposure to electromagnetic radiation. (The SAR limit is 1.6 W/kg as averaged over one gram of tissue.) Cell phone rules, published in 1996, were based on studies from the 1980s, according to Bill Walker and Olga Naidenko, PhD —long before smartphones had become mainstays in everyday life. The rules do not account for decades of daily exposure, nor do they consider possible risks to children. Young children’s brains, protected by less developed skulls, absorb twice as much cell phone radiation as adults’. Children’s vulnerability and the huge increase in RF-EMF exposure has caused health agencies in France, Israel, Italy, and other areas to recommend minimizing WiFi radiation exposure for children under age 11, according to Environmental Health Trust (EHT). The EHT website (https://ehtrust.org) has information on EMF radiation health concerns.

Environmental Working Group (EWG.org) has several tips for decreasing EMF exposure, such as using speakers and holding the phone away from the body, texting instead of talking, calling when the signal is strong, and avoiding the use of radiation shields (antenna caps and keypad covers). These shields cause cell phones to transmit with more energy, increasing radiation exposure.

Glick D, et al. Autophagy: cellular and molecular mechanisms. J Pathol. May 2010;221(1):3-12.

Kim JH, et al. Activation of autophagy at cerebral cortex and apoptosis at brainstem are differential responses to 835 MHz RF-EMF exposure. Korean J Physiol Pharmacol. 2017;21(2):179-188.

Nittby H, et al. Increased blood-brain barrier permeability in mammalian brain 7 days after exposure to the radiation from a GSM-900 mobile phone. Pathophysiology. 2009;16:103-112.

Saikhedkar N, et al. Effects of mobile phone radiation (900 MHz radiofrequency) on structure and functions of rat brain. Neurol Res. December 2014;36(12):1072-9.

Walker B, Naidenko O. California Cautions Cell Phone Users: Keep Your Distance. March 6, 2017.

Hormonal Contraception and Depression

“Use of hormonal contraception, especially among adolescents, was associated with subsequent use of antidepressants and a first diagnosis of depression, suggesting depression as a potential adverse effect of hormonal contraceptive use,” according to a Danish epidemiological study led by C.W. Skovlund. The 2016 prospective cohort study used data from Denmark’s National Prescription Register and Psychiatric Central Research Register, collected from January 1, 1995 to December 31, 2013. The study included data from 1,061,997 Danish females, age 15 to 34 years (mean age 24.4 years) with no prior depression or major psychiatric diagnosis, no history of cancer, venous thrombosis, or infertility treatment, and no redeemed prescription for antidepressants. Mean follow-up was 6.4 years.

Compared to women who used barrier methods for birth control or other non-hormonal methods such as copper IUDs, women using hormonal methods had a combined relative risk (RR) for antidepressant use of 1.23 (95% CI, 1.22-1.25). RR differed according to type of product: users of a patch (norgestrolmin) had an RR of 2.0 (95% CI, 1.76-2.18); users of a vaginal ring (etonogestrel), 1.6 (95% CI, 1.55-1.69); users of a levonorgestrel intrauterine system, 1.4 (95% CI, 1.31-1.42); and users of progestogen-only pills had an RR of 1.34 (95% CI, 1.27-1.40).

The relative risks of an initial depression diagnosis or first use of an antidepressant prescription after commencing hormonal contraception decreased with age. “Adolescents (age range, 15-19 years) using combined oral contraceptives had an RR of a first use of an antidepressant of 1.8 (95% CI, 1.75-1.84),” the authors report, “and those using progestin-only pills, 2.2 (95% CI, 1.99-2.52).” Being an adolescent seeking birth control may, in itself, be linked to unrecognized confounding factors that contribute to depression onset.

This study stirred up quite a bit of controversy. Evangelos I. Kritsotakis, University of Sheffield, calculated the absolute risk of depression using the raw data in the Skovlund study. He says: “…an honest doctor would simply have to tell her patient that, on average, only 1 in 221 exposed to HC [hormonal contraception] over a year is likely to subsequently be prescribed an antidepressant because of HC (number needed to harm [NNH] is 1/0.045 = 221) and only 1 in 2441 women is likely to be diagnosed with depression at a psychiatric hospital (NNH is 1/0.0004 = 2441). For adolescents, the NNH is 1 in 92 for use of antidepressants and 1 in 556 for depression diagnosis.” Kritsotakis asks, “Do any of these absolute risk increases counterweight the benefits from birth control?”

That is a question each woman needs to decide for herself. Feeling trapped in an unwanted pregnancy has its own risks. For some women, however, hormonal contraception—depending on the type—may be an inciting or contributing factor in the development of depression. Finding a birth control method that decreases that risk may be helpful.

Kritsotakis EI. Re: Hormonal contraception use among teenagers linked to depression – Yet another example of a never ending confusion between relative and absolute risks? BMJ. 2016;354:i5289.

Skovlund CW et al. Association of Hormonal Contraception with Depression (abstract). JAMA Psychiatry. 2016 Nov 1;73(11):1154-1162.