What’s Seasonal Affective Disorder?
In addition to being the stunningly beautiful home to the Adirondack Mountains, our area is also renowned for the eternal winters, the ambient cold and the pervasive darkness. These environmental stressors can contribute to a syndrome of low energy and depression during the winter months, and the resolution of these symptoms during the spring and the summer.
Lake Placid, in a Google search, has only 162 sunny days per year, compared to the U.S. average of 205 sunny days per year. The average snowfall in Lake Placid is 102.4 inches per year, compared to the average total in the U.S. of 27.8 inches yearly. Overall, in Lake Placid, there are on average seven months of snow on the ground.
An understanding of what causes SAD (Seasonal Affective Disorder) is quite complex. In general terms, there is a genetic predisposition that primes an individual to experience these seasonal mood changes. The environmental component requires that the SAD symptoms follow the seasons clearly, so that the symptoms completely resolve in spring and summer. It has been estimated that in northern latitudes, the prevalence of SAD is 10%.
The Diagnostic and Statistical Manual for psychiatric diagnoses requires that an individual first be diagnosed with either depression or bipolar disorder (manic depression). The diagnosis of SAD requires that the mood symptoms are more significant and severe in the fall and winter.
By diagnostic criteria, these symptoms disappear completely with the spring and the summer. There is also seasonal affective depression that can occur in response to sunlight and occurs in sunny and bright locations. However, these symptoms are almost the mirror image of the classic SAD that occurs in locations where there is poor sunlight.
The spring and summer SAD increases patient depression in response to sunlight. The way to treat these spring and summer symptoms is to advise patients to stay indoors, wear sunglasses and maintain the air conditioning at a cool level.
I likely would not have learned about this variant had I not been scheduled to take my American Board of Psychiatry and Neurology medical board exam in Phoenix. I definitely did not suffer from the reverse SAD or atypical SAD, because the sunshine brightened my mood and enhanced my motivation for the test.
The classic SAD that occurs in the fall and winter months is often accompanied by weight gain that correlates with carbohydrate cravings and an overall increase in appetite. The less common type of SAD, that occurs during the spring and summer months, is frequently associated with weight loss and a poor appetite. The presence of anxiety and agitation also occurs in the variant of SAD that occurs during the summer and spring.
The treatments of choice for fall and winter SAD is to utilize bright light to simulate the brighter and sunnier months. Furthermore, these seasonal symptoms of increased depression in fall and winter and resolution of depression completely in spring and summer, must be present during two consecutive years. For example, if a person doesn’t always experience seasonal components to their mood or only appears to have such symptoms for 12 months, but not for 24 months, then the criterial for SAD in winter and fall are not consistently present. The diagnosis cannot be given if there is a duration of less than 24 months to these seasonal moods.
Bright light is usually considered the first treatment for SAD. This treatment consists of sitting in front of a bright light for 30 to 60 minutes per day at around the same time each day. It is often used each morning shortly after awakening from sleep.
The sun provides 50,000 to 100,000 “lux” of light, and the light therapy provides, by comparison, 2,500 to 10,000 lux, which is significantly less than the natural light of the sun. However, bright light therapy is often the first intervention for classic SAD that occurs in the winter and fall.
Antidepressants can be added if the light therapy alone is not helpful. Of all the antidepressants that could potentially be prescribed, the only one that has a formal SAD indication is that of Bupropion (Wellbutrin). This antidepressant has the impact of increasing dopamine activity in the brain. Dopamine is the pleasure chemical in the brain, and it increases naturally with stimuli such as observing a sports car for a man, and stimuli such as a beautiful fashion display can increase dopamine in a woman.
Exercise and chronotherapy, which refers to maintaining consistent sleep wake cycles, are both likely to effectively improve moods impacted by SAD. Woman make up, at 75%, the majority of patients with SAD. It is thought that this might be related to estrogen levels and their impact on brain transmitters such as serotonin.
The prevention of onset of SAD can be attributed to the use of Wellbutrin as a daily antidepressant, or to light therapy as a daily intervention. The use of Vitamin D supplements and psychotherapy for patients with SAD has not demonstrated the evidence yet for these treatments. Fortunately the use of Wellbutrin has demonstrated a decrease in the symptoms of SAD and it also helps to prevent developing this syndrome. It is an activating antidepressant, which means it works by motivating and energizing an otherwise depressed and withdrawn individual.
Many patients may just purchase melatonin over the counter and hope that this chemical will decrease SAD and promote healthy recovery. Whenever there is a buzz about a particular medication, it is important to gather all of the facts before prescribing it. While it is legal to prescribe meds for off label usage that are not formally approved by the FDA, the evidence to prescribe medications other than Wellbutrin is inconclusive. Studies are inconclusive regarding the efficacy of melatonin and the similar molecule agomelatine. Studies on this chemical failed to show evidence for, or evidence against, a preventive treatment.
We are living in a culture of medication preference over other forms of treatment. People who purchase melatonin don’t have any data behind it as a treatment or preventive intervention.
It is important to empathize with these folks but provide them with other evidence based interventions. For example, cognitive behavioral treatment does help to treat SAD as effectively as light therapy does. These two treatments, light therapy and cognitive behavioral therapy, are similarly effective for treatment of SAD during an active and acute episode. Cognitive behavioral therapy works by confronting the biases that we all develop, and helps to rewire the brain to function more effectively and avoid using outdated and inaccurate assumptions about oneself.
A study many years ago out of the University of Pittsburgh Medical School focused on sleep regularity (also called chronobiology). Since this sleep consistency maintains the same time for waking and falling asleep in a given individual, such sleep adaptation provides a more healthy emotional balance than individuals that have irregular sleep.
In the 2020 article in Translational Psychiatry, a review article by William H Walker et al, focuses on the role of circadian rhythm and mental heath. The article describes how there are small molecular time clocks in the brains of humans. These time clocks reset every 24 hours. It is still unclear if there is a causal relationship between circadian rhythm and mental health. There is an association between the two but it is not yet possible to state whether circadian rhythm causes mood disorders, or whether mood disorders cause circadian cycle irregularities.
One crucial issue in research is to differentiate between causality between two variables versus an association which is not causal.
For example, as noted above, it is possible that an abnormality in circadian, or internal clock, rhythm might in turn cause a mood change such as SAD.
It is possible that the two occur together, but do not exhibit a causation.
More studies in causality are needed. However, poor sleep can indeed exacerbate bipolar disorder by inducing an elevated mood and an increase in bipolar symptoms. Poor sleep can also be a byproduct of racing thoughts and mood swings and even impulsivity, all of which can occur with bipolar disorder or depression. This hypomania and feeling too good or too happy is observed in doctor training where the lack of sleep due to a night on call induces a somewhat manic affect. Instead of feeling exhausted by this lack of overnight sleep, it can also induce increases in energy and motivation so that the day after being on call isn’t as severe a slump and can be more of a boost, ironically, to get one’s tasks completed before going home.
It used to be a cryptic, even cynical, joke in medical school that the the way to treat medical student depression is by sleep deprivation. However, while this manic response is real, it generally only lasts for one night of sleep deprivation, and is not cumulative over time.