Summer Weather(01 of12)
Open Image ModalSmoking(02 of12)
Open Image ModalSmoking has long been linked with depression, though it's a chicken-or-egg scenario: People who are depression-prone may be more likely to take up the habit. However, nicotine is known to affect neurotransmitter activity in the brain, resulting in higher levels of dopamine and serotonin (which is also the mechanism of action for antidepressant drugs). This may explain the addictive nature of the drug, and the mood swings that come with withdrawal, as well as why depression is associated with smoking cessation. Avoiding cigarettes -- and staying smoke free -- could help balance your brain chemicals. (credit:Thinkstock)
Thyroid Disease(03 of12)
Open Image ModalWhen the thyroid, a butterfly-shaped gland in the neck, doesn't produce enough thyroid hormone, it's known as hypothyroidism, and depression is one of its symptoms. This hormone is multifunctional, but one of its main tasks is to act as a neurotransmitter and regulate serotonin levels. If you experience new depression symptoms -- particularly along with cold sensitivity, constipation and fatigue -- a thyroid test couldn't hurt. Hypothyroidism is treatable with medication. (credit:Thinkstock)
Poor Sleep Habits(04 of12)
Open Image ModalIt's no surprise that sleep deprivation can lead to irritability, but it could also increase the risk of depression.A 2007 study found that when healthy participants were deprived of sleep, they had greater brain activity after viewing upsetting images than their well-rested counterparts, which is similar to the reaction that depressed patients have, noted one of the study authors."If you don't sleep, you don't have time to replenish [brain cells], the brain stops functioning well, and one of the many factors that could lead to is depression," says Matthew Edlund, M.D., director of the Center for Circadian Medicine, in Sarasota, Fla., and author of "The Power of Rest." (credit:Thinkstock)
Facebook Overload(05 of12)
Open Image ModalEnd Of A TV Show Or Movie(06 of12)
Open Image ModalWhen something important comes to an end, like a TV show, movie, or a big home renovation, it can trigger depression in some people.In 2009, some "Avatar" fans reported feeling depressed and even suicidal because the movie's fictional world wasn't real. There was a similar reaction to the final installments of the Harry Potter movies. "People experience distress when they're watching primarily for companionship," said Emily Moyer-Gusé, Ph.D., assistant professor of communication at Ohio State University, in Columbus. With "Avatar," Moyer-Gusé suspects people were "swept up in a narrative forgetting about real life and [their] own problems." (credit:Thinkstock)
Where You Live(07 of12)
Open Image ModalToo Many Choices(08 of12)
Open Image ModalThe sheer number of options available -- whether it's face cream, breakfast cereal or appliances -- can be overwhelming. That's not a problem for shoppers who pick the first thing that meets their needs, according to some psychologists. However, some people respond to choice overload by maximizing, or exhaustively reviewing their options in the search for the very best item. Research suggests that this coping style is linked to perfectionism and depression. (credit:Thinkstock)
Lack Of Fish In The Diet(09 of12)
Open Image ModalLow intake of omega-3 fatty acids, found in salmon and vegetable oils, may be associated with a greater risk of depression. A 2004 Finnish study found an association between eating less fish and depression in women, but not in men. These fatty acids regulate neurotransmitters like serotonin, which could explain the link. Fish oil supplements may work too; at least one study found they helped depression in people with bipolar disorder. (credit:Thinkstock)
Poor Sibling Relationships(10 of12)
Open Image ModalAlthough unhappy relationships with anyone can cause depression, a 2007 study in the American Journal of Psychiatry found that men who didn't get along with their siblings before age 20 were more likely to be depressed later in life than those who did. Although it's not clear what's so significant about sibling relationships (the same wasn't true for relationships with parents), researchers suggest that they could help children develop the ability to relate with peers and socialize. Regardless of the reason, too much squabbling is associated with a greater risk of developing depression before age 50. (credit:Thinkstock)
Birth Control Pills(11 of12)
Open Image ModalLike any medication, the pill can have side effects. Oral contraceptives contain a synthetic version of progesterone, which studies suggest can lead to depression in some women. "The reason is still unknown," says Hilda Hutcherson, M.D., clinical professor of obstetrics and gynecology at Columbia University, in New York. "It doesn't happen to everyone, but if women have a history of depression or are prone to depression, they have an increased chance of experiencing depression symptoms while taking birth control pills," Dr. Hutcherson says. "Some women just can't take the pill; that's when we start looking into alternative contraception, like a diaphragm, which doesn't contain hormones." (credit:Thinkstock)
Rx Medications(12 of12)
Open Image Modal