Good health results from proper nutrition, regular exercise, getting a good night’s sleep and finding a sustainable balance between the obligations of work and school and the satisfaction and pleasures that come from healthy relationships, doing work that is rewarding, and other daily pursuits that make life meaningful, stimulating and interesting. People who struggle with a substance abuse problem or depressed mood find the winter months especially challenging. 

This post is offered as a concise review of research findings on the mental health benefits of good nutrition, regular exercise and restful sleep. I also review findings on S-adenosyl methionine (SAMe) and dehydroepiandrosterone (DHEA), 2 natural supplements that have antidepressant benefits.   

A Healthy Diet—An Essential Component of Good Mental Health

Research studies have established that good nutrition improves mental and emotional well-being. Deficiencies in certain B vitamins such as folate and B-12, omega-3 fatty acids, vitamin D, zinc, and magnesium are associated with an increased risk of depressed mood. Foods rich in B-vitamins such as whole grains and dark green leafy vegetables may be especially effective against depressed mood. Some B vitamins function as enzyme cofactors that facilitate the synthesis of neurotransmitters implicated in mood regulation such as serotonin, dopamine, and norepinephrine. Other natural substances such as zinc, magnesium and omega-3 fatty acids promote increased synthesis of brain-derived neurotrophic factor (BDNF) which enhances neuroplasticity, resulting in greater resilience of the brain in the face of stress and reduced risk of developing depressed mood. 

Omega-3s and some B vitamins have beneficial anti-inflammatory and neuroprotective roles, which may contribute to their mood-enhancing effects. A recent systematic review identified 12 essential nutrients that met criteria for antidepressant efficacy: folate, iron, long-chain omega-3 fatty acids (EPA, DHA), magnesium, potassium, selenium, thiamine, vitamin A, vitamin B6, vitamin B12, vitamin C, and zinc. Using an FDA database, the authors identified foods with the highest content of at least one of these nutrients. Foods with the highest antidepressant efficacy included oysters and mussels, other seafood, organ meats, leafy greens, lettuces, peppers, and cruciferous vegetables such as broccoli, cauliflower, cabbage, kale, and brussel sprouts. 

Findings of epidemiologic studies support that individuals who consume whole foods—as opposed to processed foods and fast-food diets—have reduced risk of developing depressed mood. For example, individuals who follow the Mediterranean diet or traditional food preferences in Norway, Japan, and China, all of which are rich in vegetables and fish, have a 30% lower risk of developing depressed mood than individuals with the lowest rate of adherence to a Mediterranean diet. While the Mediterranean diet and other traditional diets emphasize the above foods, the average American diet is relatively deficient in nutrient-dense foods that may have antidepressant benefits. Food preferences influencing fatty acid consumption may be directly related to different rates of depressed mood when industrialized countries are compared to more traditional cultures. Epidemiologic studies suggest that there is an inverse correlation between the risk of depressed mood and fish oil consumption. Countries, where fish is an important part of the average diet, are characterized by significantly lower rates of depressed mood and suicidality. For example, in Japan, where fish consumption is very high, only 0.12% of the population experiences a depressed mood in a given year. In contrast, New Zealanders, who consume relatively little fish, report a 6% annual rate of depression. 

In addition to the mental health benefits of specific natural supplements, there is emerging evidence that the microbiome—which consists of microorganisms that populate the large and small intestines—contributes to general physical and mental health through a variety of mechanisms, some of which may impact neurotransmitters and inflammatory molecules implicated in mood regulation. 

Restful Sleep is Important for Good Mental Health

Chronically interrupted sleep can have significant negative consequences on mood and cognitive functioning. Mind-body approaches established as beneficial for insomnia include progressive muscle relaxation, meditation, guided imagery and hypnosis. Progressive muscle relaxation and sustained deep breathing are especially effective for reducing the time needed to fall asleep in individuals with chronic insomnia. Techniques that promote deep relaxation increase parasympathetic activity (i.e., the part of the autonomic nervous system that slows the heart and calms the mind), and decreasing sympathetic activity (i.e. the part of the autonomic nervous system that increases heart rate and enhances wakefulness). Individuals who have trouble falling asleep because of anxiety or work stress may benefit from listening to relaxing imagery that contains nature sounds starting 30 minutes before their usual bedtime. Individuals who have sleep problems related to chronic pain or another medical problem often respond to progressive muscle relaxation and those who stay awake because of chronic worrying are more likely to achieve restful sleep with guided imagery. 

Cognitive approaches for relaxation such as meditation and guided imagery are probably more effective than progressive muscle relaxation for mild or situational insomnia but are of little benefit for severe insomnia (National Institutes of Health Technology Assessment Panel, 1996). Individuals with chronic pain disorders such as fibromyalgia or arthritis report significant increases in the duration of sleep and reduced pain with regular massage therapy. Individuals with chronic insomnia who consistently practice a cognitive-behavioral technique alone or in combination with a benzodiazepine or other sedative-hypnotic drug report that non-pharmacologic or combined approaches are more effective than medications alone. Further, improved sleep is sustained longer in individuals who use non-pharmacologic or integrative approaches compared with medication only. A meta-analysis of 66 studies (including approximately 2000 patients) of relaxation and mind-body approaches for insomnia concluded that all interventions examined resulted in “reliable and durable benefits” that were superior to placebo, including improved quality of sleep and reduced time needed to fall asleep. A separate meta-analysis found that although non-pharmacologic treatments of chronic insomnia are initially more expensive and require more time compared with conventional drug therapy, in the long run, they are reliable, result in sustained benefits, and are more cost-effective than drugs alone.

Many individuals who struggle with chronic insomnia become dependent on benzodiazepines such as lorazepam (Ativan™), diazepam (Valium™) and clonazepam (Klonopin™). Taking melatonin may facilitate discontinuation of benzodiazepines following chronic use however findings are inconsistent. In a 12-week single-blind placebo-controlled study, individuals who received 2mg of controlled-release melatonin were more likely to discontinue benzodiazepines compared to those taking a placebo. Individuals taking melatonin reported significantly greater improvements in sleep quality compared to the placebo group and most who continued to take controlled-release melatonin at night remained off benzodiazepines six months after the end of the study. In contrast to the above positive findings, a more recent systematic review and meta-analysis found no evidence that melatonin facilitates benzodiazepine discontinuation and inconsistent effects of melatonin on sleep quality.  

The Antidepressant Benefits of Regular Exercise 

Many people who struggle with depressed mood find the fall and winter months especially challenging. Although available mainstream treatments such as medication and psychotherapy are often beneficial, existing conventional approaches fail to alleviate depressed mood in many cases. Below I provide a concise summary of research highlights supporting the mood-enhancing benefits of regular exercise and select natural supplements. 

Findings of controlled trials and systematic reviews have established that regular exercise improves depressed mood-. Individuals who are less sedentary have a reduced risk of both depressed mood and cardiovascular disease. The immediate and long-term beneficial effects of exercise on mood are mediated by multiple factors that increase brain levels of endorphins, dopamine, norepinephrine, and serotonin, promote the development of new neurons in the brain (i.e. neurogenesis), reduce oxidative stress, and enhance immune functioning. Findings of a small fMRI pilot study suggest that regular exercise may promote increased neuroplasticity in certain brain regions, possibly resulting in improved mood. 

A meta-analysis of controlled studies (977 total subjects) on exercise used either as a single intervention or in combination with antidepressants reported that regular exercise has consistent beneficial effects on depressed mood. A systematic review of studies on exercise as an add-on therapy in individuals diagnosed with major depressive disorder found that depressed individuals who exercise regularly respond consistently better than individuals who take an antidepressant but do not exercise. Regular aerobic exercise may improve cognitive functioning in chronically depressed individuals who often experience difficulties with thinking and memory. Regular exercise also improves sleep quality in individuals who do not respond to antidepressants. This may be a significant benefit of exercise on overall resilience and day to day functioning in view of the high prevalence rate of insomnia in chronically depressed individuals. More studies are needed to determine the optimal duration and frequency of exercise for improving depressed mood. 

SAMe and DHEA— Two Supplements with Established Efficacy for Depressed Mood 

Examples of empirically validated natural product treatments of depressed mood include St. John’s Wort, S-adenosyl methionine (SAMe), the amino acid 5-hydroxytryptophan (5-HTP), l-methylfolate—a form of the B vitamin folic acid, the essential fatty acid eicosapentaenoic acid (EPA), and to a lesser extent, the amino acid Acetyl-L-carnitine and the prohormone dehydroepiandrosterone (DHEA). Placebo-controlled double-blind studies and meta-analyses show that SAMe has equivalent or superior antidepressant efficacy compared to tricyclic antidepressants. 

Meta-analyses of placebo-controlled studies show that the methyl donor S-adenosylmethionine (SAMe) is as effective as widely prescribed antidepressants when taken alone and improves overall response and may speed up response when taken with an antidepressant. An important study published in the American Journal of Psychiatry reported that SAMe may also have significant mood-enhancing benefits in individuals who do not respond to antidepressants. Combining SAMe with an antidepressant is a safe integrative way to treat depressed mood that may permit patients to reduce the dose of a prescription antidepressant by as much as 30% in some cases. In addition to improving the efficacy of antidepressants, there is evidence that the adjunctive use of SAMe may reduce sexual side effects frequently caused by SSRIs and other antidepressants. Finally, taking SAMe 400mg twice daily together with an antidepressant may improve memory and other cognitive problems that frequently accompany depressed mood. 

Like SAMe, the neurosteroid dehydroepiandrosterone (DHEA) taken alone may reduce the severity of depressed mood and can be safely used in conjunction with antidepressants increasing their efficacy. DHEA levels in the body and brain decline with normal aging, which may help explain some cases of late-onset depression. Many individuals who respond to DHEA report improvements in sexual functioning as well.  

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