A depressive disorder is a syndrome (group of symptoms) that reflects a sad and/or irritable mood exceeding normal sadness or grief. More specifically, the sadness of depression is characterized by a greater intensity and duration and by more severe symptoms and functional disabilities than is normal.

Depression can run in families, and usually starts between the ages of 15 and 30. It is much more common in women. Women can also get postpartum depression after the birth of a baby. Some people get seasonal affective disorder in the winter. Depression is one part of bipolar disorder.

Depression comes in many shapes and forms. The different types of depression have unique symptoms, causes, and effects. Knowing what type of depression you have can help you manage your symptoms and get the most effective treatment.

Major depression
Major depression is characterized by the inability to enjoy life and experience pleasure. The symptoms are constant, ranging from moderate to severe. Left untreated, major depression typically lasts for about six months. Some people experience just a single depressive episode in their lifetime, but more commonly, major depression is a recurring disorder. However, there are many things you can do to support your mood and reduce the risk of recurrence.

Atypical Depression
Atypical depression is a common subtype of major depression. It features a specific symptom pattern, including a temporary mood lift in response to positive events. You may feel better after receiving good news or while out with friends. However, this boost in mood is fleeting. Other symptoms of atypical depression include weight gain, increased appetite, sleeping excessively, a heavy feeling in the arms and legs, and sensitivity to rejection. Atypical depression responds better to some therapies and medications than others, so identifying this subtype can be particularly helpful.

Dysthymia (recurrent, mild depression)
Dysthmia is a type of chronic “low-grade” depression. More days than not, you feel mildly or moderately depressed, although you may have brief periods of normal mood. The symptoms of dysthymia are not as strong as the symptoms of major depression, but they last a long time (at least two years). These chronic symptoms make it very difficult to live life to the fullest or to remember better times. Some people also experience major depressive episodes on top of dysthymia, a condition known as “double depression.” If you suffer from dysthymia, you may feel like you’ve always been depressed. Or you may think that your continuous low mood is “just the way you are.” However, dysthymia can be treated, even if your symptoms have gone unrecognized or untreated for years.

Seasonal affective disorder (SAD)
There’s a reason why so many movies and books portray rainy days and stormy weather as gloomy. Some people get depressed in the fall or winter, when overcast days are frequent and sunlight is limited. This type of depression is called seasonal affective disorder (SAD). Seasonal affective disorder is more common in northern climates and in younger people. Like depression, seasonal affective disorder is treatable. Light therapy, a treatment that involves exposure to bright artificial light, often helps relieve symptoms.

Bipolar Disorder: When Depression is Just One Side of the Coin
Bipolar disorder, also known as manic depression, is characterized by cycling mood changes. Episodes of depression alternate with manic episodes, which can include impulsive behavior, hyperactivity, rapid speech, and little to no sleep. Typically, the switch from one mood extreme to the other is gradual, with each manic or depressive episode lasting for at least several weeks. When depressed, a person with bipolar disorder exhibits the usual symptoms of major depression. However, the treatments for bipolar depression are very different. In fact, antidepressants can make bipolar depression worse.

• Loneliness
• Lack of social support
• Recent stressful life experiences
• Family history of depression
• Marital or relationship problems
• Financial strain
• Early childhood trauma or abuse
• Alcohol or drug abuse
• Unemployment or underemployment
• Health problems or chronic pain

Depression varies from person to person, but there are some common signs and symptoms..

• Feelings of helplessness and hopelessness. A bleak outlook—nothing will ever get better and there’s nothing you can do to improve your situation.
• Loss of interest in daily activities.  No interest in former hobbies, pastimes, social activities, or sex. You’ve lost your ability to feel joy and pleasure.
• Appetite or weight changes. Significant weight loss or weight gain—a change of more than 5% of body weight in a month.
• Sleep changes. Either insomnia, especially waking in the early hours of the morning, or oversleeping (also known as hypersomnia).
• Irritability or restlessness. Feeling agitated, restless, or on edge. Your tolerance level is low; everything and everyone gets on your nerves.
• Loss of energy. Feeling fatigued, sluggish, and physically drained. Your whole body may feel heavy, and even small tasks are exhausting or take longer to complete.
• Self-loathing. Strong feelings of worthlessness or guilt. You harshly criticize yourself for perceived faults and mistakes.
• Concentration problems. Trouble focusing, making decisions, or remembering things.
• Unexplained aches and pains. An increase in physical complaints such as headaches, back pain, aching muscles, and stomach pain.

Because depression is common and often goes undiagnosed, some doctors and health care providers may ask questions about your mood and thoughts during routine medical visits. They may even ask you to fill out a brief questionnaire to help check for depression symptoms.

When doctors suspect someone has depression, they generally ask a number of questions and may do medical and psychological tests. These can help rule out other problems that could be causing your symptoms, pinpoint a diagnosis and also check for any related complications. These exams and tests generally include:

• Physical exam: This may include measuring your height and weight; checking your vital signs, such as heart rate, blood pressure and temperature; listening to your heart and lungs; and examining your abdomen.
• Laboratory tests: For example, your doctor may do a blood test called a complete blood count (CBC) or test your thyroid to make sure it's functioning properly.
• Psychological evaluation: To check for signs of depression, your doctor or mental health provider will talk to you about your thoughts, feelings and behavior patterns. He or she will ask about your symptoms, and whether you've had similar episodes in the past. You'll also discuss any thoughts you may have of suicide or self-harm. Your doctor may have you fill out a written questionnaire to help answer these questions.

As with any chronic illness, getting an early medical diagnosis and medical treatment may help reduce the intensity and duration of depression symptoms. It will also reduce the likelihood of a relapse.

To treat depression effectively, your doctor may use psychotherapy (counseling), medications such as antidepressants, or a combination of these therapies. It may take weeks for an antidepressant to fully work to ease depression symptoms. So it's important to trust your doctor and stay on the medication.

Depression is a serious illness that can take a terrible toll on individuals and families. Untreated depression can result in emotional, behavioral and health problems that affect every area of your life. Complications associated with depression include:

• Alcohol abuse
• Substance abuse
• Anxiety
• Heart disease and other medical conditions
• Work or school problems
• Family conflicts
• Relationship difficulties
• Social isolation
• Suicide
• Thickened skin and bacterial skin infections caused by scratching in an attempt to relieve severe itching
• Fluid and electrolyte imbalance in the case of severe pustular psoriasis
• Low self-esteem
• Depression
• Stress
• Anxiety
• Social isolation

Although depression is a highly treatable condition, some forms of depression may not be preventable. That's because depression may be triggered by a chemical malfunctioning in the brain. However, the latest medical studies confirm that depression may often be alleviated or sometimes prevented with good health habits.

Proper diet, exercise, taking time out for fun and relaxation, not overworking, and saving time to do things you enjoy may work together to prevent a depressed mood.