Category Archives: mental health

Bright Light: Depression, Insomnia, and the sleep/wake cycle


I recently wrote an article for the Natural Medicine Journal about a study that showed the positive effects of wearing bright light glasses to treat depression. Bright light therapy has been popular for the past few decades to treat seasonal as well as non seasonal depression, but this is the first study to utilize a device that is worn like a pair of glasses and shines light down into the eyes of the wearer. In the past, subjects have used light boxes which work equally well, but the glasses have the advantage of allowing the wearer to be able to do other things during treatment.

While this study is interesting in itself, it brings up some fascinating questions about the role of light and dark, the sleep/wake cycle, and the establishment of a healthy circadian rhythm in mood regulation.

In this particular study, the participants (who were all teenagers receiving inpatient treatment for depression) were asked to complete a “Chronicity” questionnaire to establish their most productive time of day. None of the participants were found to be strongly morning people. There are many studies that have found a link between “eveningness” and depression. Additionally, insomnia (which is associated with eveningness) has been found to have an even greater impact on negative emotions.

So how does bright light impact the body to influence emotion and the circadian rhythm? In studies of bright light therapy, the light used emits 10,000 lumens, which is roughly equivalent to sunlight 40 minutes after sunrise on a clear day. When light hits the retina of the eye, the retina itself actually produces serotonin and dopamine, which help to maintain a good mood. The glasses in particular (as well as sunlight) emit blue light, which is the part of the visible light spectrum that is most stimulatory. We can surmise that if a person is spending the majority of their most wakeful hours when it is dark, it is possible that they aren’t making as much of these chemicals.

Conversely, blue light in particular suppresses retinal production of melatonin, which is one of the primary neurotransmitters responsible for sound sleep. Most of us have heard that watching screens such as the computer, TV, or phone before bed can impact sleep. This is because blue light emitted from these screens prevents the body from making melatonin which is necessary for sleep. Studies have found that people who wear blue-light blocking glasses for three hours before bed can correct insomnia and have more restful sleep.

Regardless of your light source, starting the day with exposure to healthy bright light will help you to make the chemicals you need to keep your mind feeling happy and at ease. At the end of the day, minimizing exposure to bright light and blue light in particular will help your body fall asleep more easily and have a more restful night!

“We Think What We Eat?” How the Health of the Gut Impacts the Health of the Mind

We have all heard of the “mind-body connection.” This is the theory that the way we think (positive, negative, anxious, relaxed etc) influences the health of the rest of the body. Our thought patterns initiate a cascade of neural and hormonal signals that have the potential to impact how all the systems of the body function; anyone who has ever gotten a stomachache from worrying about something has first hand experience of this.

However, what about the opposite? We are finding that more than we ever realized, the health of the digestive tract can profoundly impact our mental health.

Going back to the stomachache example, there is a fascinating interplay between our digestion and mood, referred to as the “gut-brain axis”. Stress hormones and neurotransmitters produced during times of anxiety and stress can alter the integrity of the digestive system, which can lead to chronic GI problems such as IBS or other inflammatory diseases. Going the other way, the function of the gut generally, and the makeup of the microbiome specifically (the bacteria that normally live in the digestive tract) can have a profound impact on symptoms of depression and anxiety.

Studies are suggesting that major stressors early in life can predispose a person to inflammatory bowel disease (IBD). The two types of IBD can also be called Ulcerative colitis or Crohn’s disease; these are long-lasting, possibly lifelong conditions that break down the walls of the gut and can profoundly impact a person’s digestive capacity. Those damaged intestinal walls release a variety of chemicals that trigger similar inflammatory responses in the nervous system, causing anxious and depressive symptoms. Similarly, in Irritable bowel syndrome (IBS) cells from the walls of the intestines have been found to produce lower amounts of serotonin, one of the primary neurotransmitters that helps us feel happy and balanced. This leads to increased sensations of discomfort in the gut, but also communicates with the brain to decrease the mood.

Even beyond the signals sent by an inflamed gut that can irritate the brain, the makeup of bacteria living in the digestive tract (what we call the “microbiome”) also significantly impact mood. The bacteria in the microbiome produce many of our neurotransmitters, such as GABA, serotonin and dopamine. These chemical signals impact mood by traveling from the gut up the vagus nerve to the brain. Particularly in IBS, many studies have found that reestablishing a healthy microbiome will improve digestive as well as emotional symptoms. A new class of drug has even been introduced, called a “Psychobiotic”. The idea behind these is that the patient ingests probiotic bacteria designed to produce mood enhancing neurotransmitters in the gut, thereby improving mental health.

Athletes in particular have been found recently to have increased rates of digestive concerns along with increased anxiety and depression. It is theorized that intense training for elite athletes causes stressors that deplete the lining of the digestive tract along with changing the makeup of the microbiome. Additionally, many elite athletes are counseled to eat diets that are very low in starch, which is the primary food source for most of the “good” bacteria that lives in the gut. This further attenuates the microbiome, which causes more digestive disturbance and lower production of neurotransmitters and can result in IBS, anxiety, and depression.

So what can we do every day to improve the health of our digestion and our mental health?

  • Stress management: stress (fight or flight) hormones suppress our rest and digest hormones. This means your digestive tract does not rejuvenate itself when we are stressed out which can make it sick.
  • Eat a healthy variety of plant based foods to replenish healthy bacteria to the gut. This includes organically grown produce, healthy complex carbohydrates such as whole grains, root vegetables, and winter squash, and naturally fermented foods such as sauerkraut and pickles.
  • Eat in a relaxed manner to engage your rest and digest hormones.  No standing at the sink or eating on the run!
  • If you are having trouble digesting your food, Warming foods such as soup and steamed veggies are easier to digest than cold foods like salads and veggie sticks.
  • Adequate sleep also gives the digestive tract time to rejuvenate itself.  If your brain needs more sleep so does your gut!
  • If you are training for an athletic event, make sure to include rest days and rejuvenating activities such as restorative yoga, stretching, breathing exercises, or tai chi to help the digestive tract restore itself.

Good luck and happy eating!