Dear Doctors: When I hear about seasonal depression, it has to do with winter. Supposedly it's because of the shorter days and the lack of daylight. But I feel the start of depression whenever summer comes, which can't be about the light. Why would that happen? What can I do?
Dear Reader: It's true that when people talk about a downward emotional shift tied to a change of seasons, winter is most often the culprit. As you point out, the shorter days and longer nights play a big role. The steady decrease of daylight hours is believed to affect levels of melatonin and serotonin. These are brain chemicals that affect mood and sleep. With colder weather, more time is spent indoors. This can lead to fewer natural social interactions and contribute to feelings of isolation. Repetitive winter tasks, like shoveling snow or dressing and undressing just to step outside, can each add a measure of stress. So can simply being cold.
While not as common as winter-based seasonal depression, the summertime blues you are experiencing are indeed a real thing. It is part of a condition known as seasonal affective disorder, or SAD. As with its wintry cousin, summertime SAD is marked by symptoms that can include anxiety, irritability, low energy, disrupted sleep and feelings of sadness or hopelessness. And because summer is supposed to represent a carefree and joyful stretch of time, people with summer SAD are sometimes also weighed down by guilt.
As with winter SAD, summertime depression is believed to involve both physiological and lifestyle triggers. Longer days mean later twilights. For some people, this can affect sleep cycles and contribute to the onset of depression. Longer days often also disrupt the routines that got us through the winter. These changes can be stressful. So can heat and humidity. For some people, being included in -- or left out of -- summertime group activities can trigger social anxiety. Genetics may also play a role. Studies of identical twins have found that siblings often shared similar patterns of seasonal changes in mood and behavior. Newer research, still in the earliest stages, has identified gene variants that may alter how serotonin affects the brain.
A useful first step in steadying your summertime mood is to safeguard your daily routine. Try to stick to the same sleep, meal and exercise schedule you follow the rest of the year. With later sunsets and early sunrises, the sleep part of the equation can become a challenge. That makes blackout curtains for the bedroom a worthwhile investment. And try to steer clear of heat stress. Use air conditioning and fans as needed in the house. When you can, save exertion and outdoor activities for the cooler parts of the day. There is also evidence that cognitive behavioral therapy can be effective in managing seasonal mood swings. It's a form of talk therapy that helps people flag and change harmful mental habits. The good news is that even small lifestyle adjustments can help ease the summertime blues.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
