Published by the Students of Johns Hopkins since 1896
November 20, 2024

Feeling unusually sad? Chances are, you might have SAD - To Health With It

By LISA ELY | October 29, 2008

Ahh ... Leaves are turning golden-red and brown, the wind is brisk and chilly, the sun comes out later and it's already sunset when I head to the library. My breath puffs out in little clouds, the stars seem brighter and everyone is getting their yearly flu shot - autumn!

Weather affects me in a lovely way, but not all people are so. Seasonal changes in weather can have detrimental effects on many people both physically and mentally.

The physical part is obvious - it gets colder, you may not dress well enough, it rains, you get cold more easily, your immune system is more susceptible, you get sick.

But other than being a pain in the bum because now you have to wear gloves and galoshes and get shots, how would weather affect you mentally?

Many people suffer from a type of depression known as Seasonal Affective Disorder, or SAD. Although the exact numbers are unknown, it's estimated that up to six percent of the U.S. population suffers from SAD, and between 10 percent and 20 percent of people suffer at least mild symptoms of SAD.

SAD is much more common in adults than children, and up to 70 percent of all cases of SAD are in women. SAD is more often a winter affliction, when the days become shorter and there is less available daylight.

However, some people suffer from summer SAD. This is generally referred to as Reverse SAD.

SAD is thought to be related to the changes in the body's exposure to sunlight, which could trigger changes in amounts of chemicals in the body.

Symptoms of winter SAD are similar to symptoms of normal depression: fatigue, changes in mood, sleeping patterns and appetite, difficulty concentrating and weight gain. These symptoms go together: Generally people with SAD have extreme fatigue and therefore sleep a great deal more.

SAD often affects a person's ability to concentrate and enjoy things they normally like to do. Weight gain concurs with the change in appetite - but unlike normal depression, where there is a common loss of appetite and weight, SAD may cause cravings for starchy, sugary foods and a tendency to overeat.

The exact causes for SAD are unknown, but SAD is much more common in the arctic regions and much less common the closer you get to the equator. In the United States, SAD has a prevalence of 1.5 percent in Florida and about nine percent in the northern states.

This concurrence in SAD prevalence with latitude change started the theory that SAD is caused by changes in the body's exposure to sunlight. Studies show that when people who get SAD travel to areas near the equator with longer daylight hours, they no longer express their seasonal SAD symptoms.

Changes in daylight hours can affect the body's circadian rhythm and may affect the body's amounts of serotonin and melatonin.

The circadian rhythm is the body's sleeping-waking cycle, or the biological clock. It is affected by light and darkness and controls bodily functions such as sleeping, waking and temperature.

Disrupting the circadian rhythm by changing daylight hours can cause disruptions in the body's ability to stay awake or regulate its many systems, and this can cause depression.

Particularly, daylight affects the body's production of melatonin, a hormone whose main function is to induce sleep. Melatonin is an important regulator of the circadian rhythm. Melatonin is produced by the pineal gland and is inhibited by light.

In the evening, when light levels decrease, melatonin is produced and starts circulating through the body. SAD patients have consistently higher daytime levels of melatonin during winter, causing fatigue: evidence of an off-cycle circadian rhythm.

Because melatonin influences the pituitary gland, which controls secretion of thyroid hormones, adrenaline and cortisol, melatonin disrupts our metabolism (causing cravings) and our energy (fight-or-flight) levels.

Other research suggests that decreased daylight hours may cause a drop in the body's levels of serotonin, a neurotransmitter that affects mood. At night, the pineal gland signals serotonin to be converted into melatonin, inducing sleep, and during the day, the pineal gland turns off the call for melatonin production, and higher levels of serotonin wake us up and energize us. Fewer hours of daylight can cause an increase in melatonin and a decrease in serotonin, causing fatigue, depressed mood, hopelessness and anxiety.

The most common treatments for SAD are antidepressants, melatonin supplements, or prescribed psychiatric medication. Another common treatment is bright light treatment. The affected person sits in front of a special lamp designed to provide intense illumination.

Unfortunately, we attend Hopkins. The most common symptoms of SAD - primarily depression, hopelessness, fatigue, social withdrawal, oversleeping, difficulty concentrating, increased appetite and weight gain - are also symptoms of doing what we do: go to Hopkins.

We study, study, work, study, study. We get depressed and hopeless because of bad grades. We pull all-nighters. We eat more. We have no social lives. We sleep when we can, and we are always, always tired. No big surprise.

But if these symptoms are more than usually pronounced, SAD, or normal depression, could be the cause. If you notice these (extreme) symptoms in yourself or a friend, talk to an RA, a parent, a professor or a friend, or go to APTT. The JHU Counseling Center can help as well. All services are confidential and free of charge.

SAD and normal depression are serious. If you notice a friend with these symptoms, do your best to cheer them up, talk to them and encourage them to get help.


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