Depression: What Is It?
It’s natural to feel down sometimes, but if that low mood lingers day after day, it could signal depression. Major depression is an episode of sadness or apathy along with other symptoms that lasts at least two consecutive weeks and is severe enough to interrupt daily activities. Depression is not a sign of weakness or a negative personality. It is a major public health problem and a treatable medical condition.
Shown here are PET scans of the brain showing different activity levels in a person with depression, compared to a person without depression.
Depression Symptoms: Emotional
The primary symptoms of depression are a sad mood and/or loss of interest in life. Activities that were once pleasurable lose their appeal. Patients may also be haunted by a sense of guilt or worthlessness, lack of hope, and recurring thoughts of death or suicide.
Depression Symptoms: Physical
Depression is sometimes linked to physical symptoms. These include:
- Fatigue and decreased energy
- Insomnia, especially early-morning waking
- Excessive sleep
- Persistent aches or pains, headaches, cramps, or digestive problems that do not ease even with treatment
Depression can make other health problems feel worse, particularly chronic pain. Key brain chemicals influence both mood and pain. Treating depression has been shown to improve co-existing illnesses.
Depression Symptom: Appetite
Changes in appetite or weight are another hallmark of depression. Some patients develop increased appetite, while others lose their appetite altogether. Depressed people may experience serious weight loss or weight gain.
Impact on Daily Life
Without treatment, the physical and emotional turmoil brought on by depression can derail careers, hobbies, and relationships. Depressed people often find it difficult to concentrate and make decisions. They turn away from previously enjoyable activities, including sex. In severe cases, depression can become life-threatening.
epression: Who’s at Risk?
Anyone can become depressed, but many experts believe genetics play a role. Having a parent or sibling with depression increases your risk of developing the disorder. Women are twice as likely as men to become depressed.
Causes of Depression
Doctors aren’t sure what causes depression, but a prominent theory is altered brain structure and chemical function. Brain circuits that regulate mood may work less efficiently during depression. Drugs that treat depression are believed to improve communication between nerve cells, making them run more normally. Experts also think that while stress — such as losing a loved one — can trigger depression, one must first be biologically prone to develop the disorder. Other triggers could include certain medications, alcohol or substance abuse, hormonal changes, or even the season.
Illustrated here are neurons (nerve cells) in the brain communicating via neurotransmitters.
As of yet, there is no lab test for depression. To make an accurate diagnosis, doctors rely on a patient’s description of the symptoms. You’ll be asked about your medical history and medication use since these may contribute to symptoms of depression. Discussing moods, behaviors, and daily activities can help reveal the severity and type of depression. This is a critical step in determining the most effective treatment.