Seasonal affective disorder (SAD) is one of the few ailments that is on a clock: It usually begins in October, and people who suffer from it usually feel the full effects in January and February. We also know that it’s more common for people living in places that get less sunlight during the winter and it’s more common in women than men, according to psychologists and researchers.
Traditionally, SAD is treated with antidepressant medication or light therapy, but there has been recent piloting towards a new approach using cognitive behavioral therapy (CBT), looking at the effects of CBT method on reducing negative thought patterns for people with SAD, using the Socratic method to interrupt negative thought patterns and make way for more mood-neutral thoughts, while simultaneously focusing on behavior and helping people to make slight shifts in their habits.
Here are a few questions to consider.
What is seasonal affective disorder?
Seasonal affective disorder is a type of clinical depression that commonly occurs in the fall and winter months and typically resolves in the spring and summer. While it can take any seasonal pattern, the fall/winter type is overwhelmingly the most common. The only thing that makes it different from garden-variety depression is the seasonal pattern that it follows.
Because of their similarities, SAD is often misdiagnosed as depression. It sometimes takes a few years for people who have this pattern to recognize that it’s a pattern, and that it’s tied to the seasons.
What are the most common symptoms?
Because we’re diagnosing depression when diagnosing SAD, we look for at least five of the nine diagnostic symptoms of depression. We’re diagnosing a depression that follows a seasonal pattern, meaning we’re looking for depressive symptoms that are present much of the day, almost every day, for at least two weeks. The hallmark symptoms of depression are:
Feeling consistently down for most of the day or nearly every day.
A loss of interest in the things that would have otherwise been enjoyable, such as social activities that previously would have brought a sense of enjoyment or pleasure.
Feeling overwhelmingly tired or experiencing low energy.
Inability to hold attention and focus or experiencing difficulty in concentrating.
Feeling worthless or hopeless.
Issues with sleep. Either too little or too much. In winter depression, we tend to see hypersomnia or sleeping too much. In most cases, the individual sleeps for at least an extra hour a day compared to the spring or summer. Some patients may sleep ten to even fourteen hours a day and are still tired. It’s not restorative sleep that we’re seeing. A minority of patients, on the other hand, experience insomnia.
Changes in appetite or weight. This could be either wanting to eat a lot more or a lot less than usual. In winter depression, it’s usually wanting to eat more, and it’s usually carbohydrate-rich foods. Either sugars, starches, or both. With this, we typically see weight gain with an increased appetite or weight loss with a decreased appetite.
Agitation often accompanied by feelings of guilt and shame.
In extreme cases, thoughts of death or suicide.
Individuals can be diagnosed with SAD when they’re experiencing five of these symptoms, which need to include the first and/or second symptom.
These are not momentary symptoms; rather, they are pervasive for at least a couple of weeks. On average, it’s estimated to be five months of the year in a major depressive episode. It’s a lot of time to spend in depression, in terms of the cumulative toll that it could take on a person’s life.
Whom does it affect most?
Similar to depression, there is a pronounced gender difference for those affected by SAD. Depression in general is two times more common in women than in men, and data suggests seasonal depression is even more common in women than in men. When we look at its prevalence, we’re looking at a single snapshot in time. And we’ve found that most cases occur in young adults, typically in their twenties to thirties. We’re not entirely sure why it occurs in this age range, though, since these studies don’t follow people over time. One theory is that SAD becomes less prevalent as people age, because they learn how to cope with it or possibly move to places that don’t have winters that are as harsh.
How does SAD differ from depression? For individuals who have been previously diagnosed with depression, does that put them at an increased risk of developing SAD?
It’s estimated that up to 10 to 20 percent of recurrent depression cases follow a seasonal pattern. This is generally the course of depression, in which a depressive episode tends to return over time, with periods of time without depression between the episodes.
For SAD patients, there are unfortunately very few studies that have tried to look at the long-term trajectory of the disorder. So we don’t have a coherent idea of its outlook. We’ve tried contacting people we knew who had SAD in the past to learn about their experience and see where they’re at today, and we’ve found mixed long-term courses. A lot of them continue to experience SAD episodes every winter. Others become more subclinical, where they used to have full-threshold SAD, and now they may just have the winter blues. Some develop a completely nonseasonal course where they still have depressive episodes but it’s not tied to the seasons. And others fully remit, where they don’t have depression, seasonal or otherwise, moving forward.
In terms of how SAD differs from depression, there is a strong correlation of SAD with latitude in the United States. The farther you are from the equator, the more cases you’ll find. It is estimated that 9 percent of those people who live in Alaska suffer from SAD, compared with 1 percent of those who live in Florida. For most people—at least in the northern United States—SAD slowly begins in October. People often report an increase in their symptoms after the end of daylight saving time and experience their symptoms in full effect in January and February. It is in these two months that we find the largest proportion of SAD patients in a full major depressive episode.
Another strong link is photo period, or length of daylight. Photo period is the strongest predictor of when symptoms start in any given year for someone who has seasonal affective disorder, as well as how severe the symptoms are on a given day. The number of hours from dawn to dusk determines your photo period. We believe that photo period is what explains the onset of this disorder and can determine how bad symptoms may be on any particular day.
What is the traditional approach to treating SAD?
Light therapy was the first line of treatment developed specifically for SAD patients. It was developed at the National Institute of Mental Health under Norman Rosenthal. He was a psychiatrist who moved from South Africa to Bethesda, Maryland, to work at the National Institute of Mental Health, and he experienced SAD symptoms. He was interested in learning more about it, and seeing if others experienced similar symptoms. He put an ad in The Washington Post, asking whether anyone experienced depression in the fall and the winter, and the lab phone rang constantly for weeks at a time. They had a huge response from people who thought they had the symptoms. They brought them they seemed to follow. From this, they developed light therapy as a form of treatment.
With light therapy, the goal is to give people a very bright dose of light, first thing in the morning, to simulate an early dawn. In theory, we’re trying to jump-start a sluggish biological clock, so that circadian rhythms go back to a normal phase as if they’re in the summer, when these people are feeling good. The devices tested in clinical trials are 10,000 LUX, which is the same intensity of light from the sky at sunrise. We block out the UV rays since they’re not necessary for an antidepressant response. We’ve found that prescribing patients to sit in front of 10,000 LUX for at least thirty minutes a day is what it takes for the treatment to be effective in people who have SAD. That said, similar to finding the right antidepressant, it can be a bit of a trial-and-error process. We try to find that sweet spot of exactly how many minutes a day and at what time or times of the day it’s most effective for the patient. The optimal benefit from light therapy must be determined on an individual basis so we can balance any side effects they may experience in response to the light.
The same drugs that are effective in treating nonseasonal depression—particularly SSRIs like fluoxetine/Prozac—have been tested for SAD with a good outcome in placebo-controlled studies. There is one drug that’s FDA-approved specifically to prevent SAD, which is Wellbutrin Extended Release. There was a large multisite study—with the GlaxoSmithKlein drug—completed a few years ago with over 1,000 SAD patients. The study compared putting people on the Wellbutrin Extended Release versus a placebo, and the participants started the treatment early in the fall when they weren’t yet having their symptoms, and the study followed them into the winter. The researchers found fewer relapses on the drug than with the placebo, which led to the FDA approval of the medication. Either bright-light therapy or antidepressant medication are typically used in treating SAD.
How can cognitive behavioral therapy be used to treat SAD?
There is an extensive body of research demonstrating that CBT is an effective talk therapy for people with depression. There have also been a lot of clinical trials showing that it worked as well as antidepressant medications for improving depression. Additionally, when you follow people over time, after they’re treated to remission using CBT versus treated to remission using antidepressant medications, there are fewer relapses and recurrences among those treated with CBT than those treated with antidepressant medication.
Resist the urge to self-diagnose and self-treat. Seek evaluation from a qualified person who can figure out once and for all if it’s SAD or if it might be something else, including a depression that’s not following a seasonal course. And know that there are treatment options out there that are effective, including light therapy, antidepressant medications, and cognitive behavioral therapy. So there are reasons to be optimistic that one of these interventions will be helpful in terms of improving your experience.