Winter Blues

Everything You Need to Know to Beat Seasonal Affective Disorder

The Guilford Press

Contents

Discovering SAD

Whether by the diagnostic term "seasonal affective disorder" or the informal term "winter blues," you have probably heard about this condition.

SAD AND LIGHT THERAPY: THE EARLY YEARS

Although individual cases of SAD have appeared in the psychiatric literature for over a hundred years, and although the use of light to treat depression was suggested even in ancient times, the description of SAD as a syndrome and the systematic development of light therapy to treat it occurred as recently as the early 1980s, at the National Institute of Mental Health (NIMH). These developments involved several individuals, each of whom made an important contribution to the story. I consider myself fortunate to have been at that place at that time and to have played a key part in these events, which I describe below. And since each of us experiences our world from our own particular vantage point, it seems easiest to begin this tale of scientific discovery with my own SAD story.

My Own SAD Story

I trained as a doctor in South Africa, a country that, for all the turbulence of its politics, can truthfully boast about its climate. In Johannesburg, where I grew up, there were really only two seasons: summer and winter. During summer, one could swim outdoors and eat summer fruit: peaches, papaya, mangoes. During winter, one could not do these things. It was warm outdoors during the day, though at night you needed a sweater. Spring and autumn were transition times. After several months of winter, the blossoms would appear, and you knew it was spring. Likewise, when the long summer was over, the leaves would turn a simple brown and fall off the trees without much fuss or fanfare, and winter was there. But despite the mildness of the seasons, I was aware at some level of the effect they had on my mood. I had even considered writing a novel in which the mood of the central character changed regularly with the seasons. The novel was never written, but the seed of the idea stayed with me, germinating quietly. It required the intense seasonal changes of the higher latitudes to which I moved to activate that germ of an idea, as well as encounters with some inspiring people, who are central to this story. I arrived in the United States in the summer of 1976 and began both my psychiatric residency at the New York State Psychiatric Institute and research into disorders of mood regulation. The summer days felt endlessly long, and my energy was boundless. I had never experienced such long summer days in Johannesburg, which is far nearer to the equator than New York City.

As the months passed, I was struck by the drama of the changing seasons. I had been unprepared for the brilliant colors of the autumn leaves in the North, the crisp days and cold nights, and most of all, the disappearance of the light. I had not anticipated how short the days would be. When the sun shone, its rays struck the earth at a strange, oblique angle, and I understood what Shelley meant when he wrote:

Bright Reason will mock thee
Like the sun from a wintry sky.

Then daylight savings time was over and the clocks were put back an hour. I left work that first Monday after the time change and found the world in darkness. A cold wind blowing off the Hudson River filled me with foreboding. Winter came. My energy level declined, and I wondered how I could have undertaken so many tasks the previous summer. Had I been crazy? Now there seemed to be no alternative but to hang in and try to keep everything afloat. I understood for the first time the stoic temperaments of the northern nations. Finally, spring arrived. My energy level surged again, and I wondered why I had worried so over my workload.

I registered all these impressions, but I did not put them together into a cohesive story—and I probably would never have done so had it not been for the events that followed and the remarkable people I was to meet. At the end of my residency I went to the NIMH in Bethesda, Maryland, to undertake a research fellowship with Frederick Goodwin, whom I had heard speak on the topic of manic–depressive illness from both biological and psychological points of view. Goodwin made the subject come alive, describing how our shifting moods and fluctuating perceptions of the world correspond to certain changes in our brain chemistry. Since mind and brain seemed equally fascinating frames of reference, I wanted to use both models to try to understand mood disorders.

Shortly before my first visit to the NIMH, I met Alfred Lewy, one of several psychiatrists working with Goodwin at the time. Lewy had just developed a technique to measure the hormone melatonin, in collaboration with Sanford Markey. Melatonin is produced by the pineal gland, a pea-sized structure tucked underneath the brain. Each night, like clockwork, the pineal gland releases melatonin into the bloodstream in minute quantities and continues to do so until dawn. The secretion of melatonin signals the duration of darkness and thus serves as an important seasonal time cue in animals. Although it is unclear whether melatonin is instrumental in causing seasonal changes in humans, research in this area proved to be a critical step in the description of SAD and the development of light therapy.

Lewy and I spoke about our common interests and the various directions in which our research might take us. On occasion, we chatted over a mass spectrometer, the instrument he had used to develop his technique for measuring melatonin. It looked like a very large washing machine. He injected samples of clear fluid into a small hole in the top, and reams of paper rolled off it, while inked pens traced out a graph upon the paper. He pointed to one blip on the graph and said, "That's melatonin." I was suitably impressed.

After I joined Goodwin's group, I was assigned to work most closely with Thomas Wehr, an outstanding clinical researcher who had for some years been studying biological rhythms in an attempt to learn whether abnormalities in these rhythms might be the basis of the mood disturbances in depression and mania. Shortly before my arrival at the NIMH, Lewy and Wehr had shown that bright light was capable of suppressing the secretion of human melatonin at night—a finding that was to have great influence over the events that followed. There was a buzz in Goodwin's group at that time—a sense of excitement—and I felt certain I had come to the right place.

A Light-Sensitive Scientist

Although many people were responsible for the discovery of SAD, our steps toward this end can all be traced back to the actions of one man: Herb Kern. In some ways, Herb might have appeared to be an unlikely person to initiate a new area of medical investigation, for he was not himself a medical professional, but a research engineer with a major corporation. I met Herb a year after arriving at the NIMH. At 63, he was a youthful-looking man with a wiry build, a crew cut, and a twinkle in his eyes. He was intensely curious, and he had noted in himself a regular pattern of mood and behavior changes going back at least 15 years. A scientist by nature and training, he had kept careful notes of these changes in numerous small notebooks. He observed that each year, from July onward, his mood would decline and he would withdraw from the world. At these times, he lacked energy, had difficulty making decisions, lost interest in sex, and felt slowed down and "ready for hibernation." It was hard for him to get to work in the morning, and once there, he would sit at his desk, fearful that the telephone would ring, obliging him to have a conversation with someone. It is typical for a depressed person to withdraw—to have neither the desire nor energy to interact with others, which often seems like an impossible task. Depressed people simply want to be left alone.

More bothersome to Herb than his social isolation was his decreased creativity during his depressed periods. He would procrastinate at work because "everything seemed like a mountain" to him, and his productivity decreased markedly. It was only by grim perseverance that he was able to write up his research from the previous spring and summer. His sleep was disrupted, and his characteristic enthusiasm for life evaporated. The months would drag on like this for Herb until mid-January, when, over a two-week period, his energy would return. As he put it, "The wheels of my mind began to spin again." He had ample, even excessive, energy at these times and needed little sleep. Ideas came freely, and he was eager to communicate them. Over the next 5 or 6 months he would be very confident of his abilities, feeling as though he could "tackle anything." He was efficient and creative, needed only four hours of sleep per night, was more interested in food and sex, and acknowledged a "tendency to go overboard" in buying luxuries.

Herb had observed that his mood improved as the days lengthened and declined as they shortened, and he had actually developed a theory that this might be due to changes in environmental light. He attempted to interest several people in his hunch that his mood and energy levels were related to the time of year. One of these, Peter Mueller, a New Jersey psychiatrist in private practice who had a research background, listened to Herb and subsequently looked for other patients with a similar history. Herb was treated with several different antidepressant medications, all of which resulted in unacceptable side effects without correcting his symptoms. Herb read about the work of Goodwin, Wehr, and Lewy and found his way to the NIMH, where he asked us to work with him on his seasonal difficulties.

Lewy suggested that we treat Herb by lengthening his winter day with 6 hours of bright light—3 before dawn and 3 after dusk—in an attempt to simulate a summer day. He reasoned that since bright light is capable of suppressing melatonin in humans, it might also be capable of altering mood and behavior. This reasoning was strengthened by two observations: First, melatonin secretion is an important chemical signal for regulating diverse seasonal rhythms in animals; second, the nerve pathways involved in the suppression of melatonin secretion by light pass through parts of the brain that we believe are important in regulating many of the physical functions that are disturbed in depression, such as eating, sleeping, weight control, and sex drive. If the suppression of melatonin required light much brighter than ordinary indoor lighting, then perhaps bright light might also be necessary for the brain to perform certain mood-related functions.

We asked Herb to sit in front of a metal light box, about 2 feet by 4 feet. The box emitted as much light as one would receive while standing at a window on a spring day in the northeastern United States. We chose full-spectrum fluorescent lights—a type that mimics the color range of natural sunlight coming from a summer sky—to replicate the conditions that appeared to bring Herb out of his winter depressions. We covered the lamps in the light box with a plastic diffusing screen to create a smooth surface. Modern light boxes differ to some degree from the one we originally used in treating Herb. We now realize that it is unnecessary to use full-spectrum light and that, in fact, the ultraviolet rays present in some full-spectrum lights may actually be harmful to the eyes and the skin. In addition, newer light box models are smaller and more portable. Some models are tilted toward the person's eyes, an arrangement that produces less glare and is therefore more comfortable. Specific details about light boxes are provided in Chapter 7, "Light Therapy," and Part IV, "Resources."

Within 3 days, Herb began to feel better. The change was dramatic and unmistakable. He was moving into his spring mode several weeks ahead of schedule. Did we dare hope that we might have found a new type of treatment for depression? Intriguing as this possibility was, our excitement was immediately tempered by our scientific training. After all, Herb had been heavily invested in the light therapy. Might his response not have been a placebo effect? This effect has dogged behavioral researchers for years, and studies of light therapy would prove to be no exception.

A Human Bear

During the same winter that Herb was receiving light treatment at the NIMH, Peter Mueller, a private practitioner, in consultation with Al Lewy, tried artificial light treatment with another patient, whom we will call "Bridget." She also appeared to benefit from light and had an unusually good winter that year. The following summer, as luck would have it, Bridget moved to the Washington metropolitan area, and Mueller suggested that she contact us. Bridget's history and her ingenuity in translating the details of her seasonal problems into a coherent story were as remarkable as Herb's.

She was a professional in her mid-30s, who had been aware of disliking winter since childhood. But it was not until her early 20s that a regular pattern of seasonal changes emerged. Bridget's problem would begin each year in August or September, as she anticipated the forthcoming winter with increasing anxiety. What triggered this dread? she wondered. Could it be the fall catalogs, with their pictures of winter clothes? Regardless of the reason, when the leaves began to turn, she would feel a strong urge to take out her winter clothes and stock her cupboards with food, "like a squirrel getting ready for winter."

As winter approached, Bridget experienced many symptoms similar to those described by Herb, such as feelings of extreme fatigue—a leaden sensation that made her want to lie down and sleep all day. During these times, she had a marked craving for sweets and starches and overate. As with Herb, Bridget continued to struggle in to work each day, though her productivity declined markedly. When spring arrived, her depression lifted and was replaced by elation. In her earlier years, she would forget her winter difficulties once they were over. "I was like the grasshopper," she remarked, "singing and playing all summer long," indifferent to the next winter that was to come.

Bridget had also observed that other changes in the environment besides the seasons seemed to affect her mood. She had visited the Virgin Islands during the two winters before her first light treatment. Both times, her mood had improved markedly just days after arriving on the islands—only to relapse a few days after her return to the North. She had lived previously at different latitudes: Georgia, New York, and Quebec. The farther north she lived, the earlier her depressions began, the more depressed she felt, and the later were her spring remissions. She began to suspect that something in the environment was driving her mood changes—perhaps the light. Why else would she crave it so? Why else did she hate her poorly lit office? She made up any excuse to seek out the brightly lit photocopying room. Light treatment made good sense to Bridget. She was eager to try it and was delighted to find that it worked for her.

IN SEARCH OF SAD

Unusual individual cases have historically played an important role in medical research in general and psychiatry in particular. We wondered whether Herb's and Bridget's symptoms might be examples of a special seasonal kind of depression and whether they might help us understand how others respond to the changing seasons and environmental light.

Although single cases may be of great importance in generating new hypotheses, we generally need groups of patients to test them experimentally. Mueller said he had encountered several other patients with seasonal depression. We wondered how common the problem was. Were there any other such individuals in the Washington, DC, area who might be interested in participating in a research program? I called a few local psychiatrists who specialized in treating depression, but they said they had not encountered the problem. I concluded that it must be quite rare and that the only chance we had of finding such a group was by publicizing our interest in theWashington Post. Sandy Rovner, a journalist who specialized in health issues, sat across the room from me, tape recorder in hand, and listened to my story. She decided it would be of interest to her readers and wrote an article for the Post, which launched an entire field of research. Rovner's article began with Bridget's own words: "I should have been a bear. Bears are allowed to hibernate; humans are not."

The response to the article took us all by surprise. Instead of our hearing from a handful of afflicted people, the phones rang for days and we received thousands of responses from all over the country. We sent out screening questionnaires, which were returned by the hundreds. I read them with a growing sense of excitement. In psychiatric research, heterogeneity is a major problem. In other words, the same condition may have diverse presentations and causes, which has proven to be an enormous obstacle to psychiatric researchers. As I read the questionnaires, it seemed as though Bridget had been cloned—one person after another reported the symptoms of the condition that we went on to call SAD. I wondered whether this uniformity in symptoms might reflect a common underlying biology, which might explain their favorable responses to light.