Seasonal Affective Disorder
Seasonal Affective Disorder (SAD) is not considered as a
separate disorder. It is a type of depression displaying a recurring
seasonal pattern. To be diagnosed with SAD, people must meet full
criteria for major depression coinciding with specific seasons
(appearing in the winter or summer months) for at least 2 years.
Seasonal depressions must be much more frequent than any non-seasonal
depressions.
Symptoms of Major Depression
- Feeling depressed most of
the day, nearly every day
- Feeling hopeless or
worthless
- Having low energy
- Losing interest in
activities you once enjoyed
- Having problems with sleep
- Experiencing changes in
your appetite or weight
- Feeling sluggish or
agitated
- Having difficulty
concentrating
- Having frequent thoughts
of death or suicide.
Symptoms of the Winter Pattern of SAD include:
- Having low energy
- Hypersomnia
- Overeating
- Weight gain
- Craving for carbohydrates
- Social withdrawal (feel
like "hibernating")
Symptoms of the less frequently occurring summer seasonal
affective disorder include:
- Poor appetite with
associated weight loss
- Insomnia
- Agitation
- Restlessness
- Anxiety
- Episodes of violent
behavior
Risk Factors
Attributes that may increase your risk of SAD include:
- Being female.
SAD is diagnosed four times
more often in women than men.
- Living far
from the equator. SAD is more frequent in people who
live far north or south of the equator. For
example, 1 percent of those who live in Florida and 9 percent of those
who live in New England or Alaska suffer from SAD.
- Family
history. People with a family history of other types of
depression are more likely to develop SAD than people who do not have a
family history of depression.
- Having
depression or bipolar disorder. The symptoms of
depression may worsen with the seasons if you have one of these
conditions (but SAD is diagnosed only if seasonal depressions are the
most common).
- Younger Age.
Younger adults have a higher risk of SAD than older adults. SAD has
been reported even in children and teens.
The causes of SAD are unknown, but research has found some
biological clues:
- People with
SAD may have trouble regulating one of the key neurotransmitters
involved in mood, serotonin. One study found that
people with SAD have 5 percent more serotonin transporter protein in
winter months than summer months. Higher serotonin transporter protein
leaves less serotonin available at the synapse because the function of
the transporter is to recycle neurotransmitter back into the
pre-synaptic neuron.
- People with
SAD may overproduce the hormone melatonin. Darkness
increases production of melatonin, which regulates sleep. As winter
days become shorter, melatonin production increases, leaving people
with SAD to feel sleepier and more lethargic, often with delayed
circadian rhythms.
- People with
SAD also may produce less Vitamin D. Vitamin D is
believed to play a role in serotonin activity. Vitamin D insufficiency
may be associated with clinically significant depression symptoms.
Treatments and Therapies
There are four major types of treatment for SAD:
- Medication
- Light therapy
- Psychotherapy
- Vitamin D
These may be used alone or in combination.
Medication
Selective Serotonin Reuptake Inhibitors (SSRIs) are used to
treat SAD. The FDA has also approved the use of bupropion , another type of
antidepressant, for treating SAD.
As with other medications, there are side effects to SSRIs.
Talk to your doctor about the possible risks of using this medication
for your condition. You may need to try several different
antidepressant medications before finding the one that improves your
symptoms without causing problematic side effects. For basic
information about SSRIs and other mental health medications, visit NIMH's Medications
webpage. Check the FDA's website for the latest
information on warnings, patient medication guides, or newly approved
medications.
Light Therapy
Light therapy has been a mainstay of treatment for SAD since
the 1980s. The idea behind light therapy is to replace the diminished
sunshine of the fall and winter months using daily exposure to bright,
artificial light. Symptoms of SAD may be relieved by sitting in front
of a light box first thing in the morning, on a daily basis from the
early fall until spring. Most typically, light boxes filter out the
ultraviolet rays and require 20-60 minutes of exposure to 10,000 lux of
cool-white fluorescent light, an amount that is about 20 times greater
than ordinary indoor lighting.
Psychotherapy
Cognitive behavioral therapy (CBT) is type of psychotherapy
that is effective for SAD. Traditional cognitive behavioral therapy has
been adapted for use with SAD (CBT-SAD). CBT-SAD relies on basic
techniques of CBT such as identifying negative thoughts and replacing
them with more positive thoughts along with a technique called
behavioral activation. Behavioral activation seeks to help the person
identify activities that are engaging and pleasurable, whether indoors
or outdoors, to improve coping with winter.
Vitamin D
At present, vitamin D supplementation by itself is not
regarded as an effective SAD treatment. The reason behind its use is
that low blood levels of vitamin D were found in people with SAD. The
low levels are usually due to insufficient dietary intake or
insufficient exposure to sunshine. However, the evidence for its use
has been mixed. While some studies suggest vitamin D supplementation
may be as effective as light therapy, others found vitamin D had no
effect .
Join a Study
Clinical trials are research studies that look at new ways to prevent,
detect, or treat diseases and conditions, including seasonal affective
disorder. During clinical trials, treatments might be new drugs or new
combinations of drugs, new psychotherapies or devices, or new ways to
use existing treatments. The goal of clinical trials is to determine if
a new test or treatment works and is safe. Although individual
participants may benefit from being part of a clinical trial,
participants should be aware that the primary purpose of a clinical
trial is to gain new scientific knowledge so that others may be better
helped in the future.
-NIH