Depression is more than just feeling sad, guilty or blue from time-to-time. Depression, also called major depressive disorder (MDD) or unipolar depression, affects daily feelings, actions, thoughts and wellness. Clinical depression is a mood disorder that causes profound, long-lasting feelings of severe sadness, loss of interest in daily activities, and often withdrawal from family and friends. In the most severe cases, thoughts of worthlessness, self-harm or suicide may occur.

Depression can make it difficult to engage in activities such as family life, work, and social events. It may be associated with abnormal biochemical changes in the brain that lead to depressed feelings and sadness. Family history (genetics) and life circumstances can also play a role.

Medical treatment is required as depression will not go away on its own; however, most forms of depression respond well to treatment such as prescription antidepressants, psychotherapy (talk therapy), and a combination of two. Depression may frequently recur after the first episode.

Depression not only negatively impacts family, work and social life, depression can adversely affect common physical ailments, such as:

  • arthritis
  • heart disease
  • cancer
  • diabetes.

In fact, many patients who have depression instead seek medical help for issues like pain or headache. Once the depression is addressed, the physical concerns often improve.

On the hand, certain medical conditions can cause symptoms of depression, for example some hormone imbalances (postpartum depression, premenstrual dysphoric disorder (PMDD). Those with depression may have other (co-morbid) psychiatric conditions, too, such as attention deficit hyperactivity disorder (ADHD), obsessive compulsive disorder (OCD), or substance abuse (illegal drugs, prescription opioids, alcohol).

Depression is not a sign of weakness or the fault of the person who has the diagnosis. Many people feel they will be stigmatized if they are diagnosed with depression. However, it is important that anyone who suspects they have depression seek immediate help from trusted family members and healthcare providers.

Depression is a treatable disease with a high rate of success. Most people with depression can be treated with medication and talk therapy, and lead normal, productive lives. However, left untreated, depression and its subtypes can result in a lowered quality of life, isolation from family and friends, and even suicidal thoughts or actions.

Is Depression a Common Illness?

If you suffer from depression, know that you are not alone. In the National Survey on Drug Use and Health (NSDUH):

  • Roughly 16.2 million U.S. adults, or about 6.7% of this population, had at least one major depressive episode.
  • Depression is more frequent in females (8.5%) than males (4.8%).
  • A diagnosis of depression is highest in ages 18 to 25 years (10.9%).
  • Of adults with major depressive episode diagnosed in 2016, 64% had a severe level of disease.
  • Treatment of depression is not optimal; in fact, 37% of adults did not receive any treatment -- either with psychotherapy or medication.

What Causes Depression?

Depression does not play favorites and it can affect anyone independent of their age, race or socioeconomic status; however, the exact causes of depression is not known.

Depression may be due to a mixture of:

  • Biological and genetic traits.
  • Adverse health conditions.
  • Current situations such as job loss, stress, trauma, or violence.
  • Severe grief after the death of a loved one.
  • Prescription medications that lead to depressive symptoms as a side effect.
  • Alcohol use and substance abuse.

Many experts believe it is caused by chemical imbalances in the brain, which may be hereditary or may be caused by events in a person's life. Depression probably involves changes in the areas of the brain that control mood. Research suggests that changes in levels of certain chemicals in the brain called neurotransmitters, such as serotonin or norepinephrine, may be partly responsible for the occurrence of depression. Chemical reactions or communication between nerve cells may make it difficult for a person to regulate their mood.

Depression may also be genetically linked; an individual's risk for depression may be higher if they have a family history of depression. Some types of depression seem to run in families, but depression can also occur in people who have no family history of the illness.

Stressful life changes or events, such as such as job loss, divorce, physical trauma or violence, and severe grief after the death of a loved one can trigger depression in some people. Alcohol use and substance abuse may worsen or trigger depression. Most often, a combination of factors is involved and one factor cannot be identified clinically.

Hormonal changes, especially in women, may play a role. Women are especially vulnerable to depression after giving birth because of the hormonal and physical changes that occur (leading to post-partum depression). While new mothers commonly experience temporary "baby blues," depression that lasts longer than 2 to 3 weeks is not normal and requires treatment.

Depression may also be a side effect due to medications. Your doctor should review all of your medications, both prescription, over-the-counter and herbal, to rule out this cause. In addition, underlying medical disorders that can cause symptoms of depression, such as chronic fatigue syndrome, diabetes or Parkinson's disease, should also be ruled out before making the diagnosis of depression.

While the exact cause of any one person's depression is hard to pinpoint, it is known is that for most patients, medical treatment has a high rate of success.

  • The American Psychiatric Association recommends that antidepressant medication is an initial treatment choice for most patients with major depressive disorder, with symptoms ranging from mild to severe.
  • There are many medical options for depression, including psychotherapy (i.e., cognitive behavioral therapy), antidepressant medications, or a combination of the two.
  • In more severe cases, brain stimulation therapies such as electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS) may be needed.
  • Light therapy can be effective for seasonal affective disorder (SAD).

Risk Factors for Depression

According to the U.S. Centers for Disease Control and Prevention (CDC), depression is a common illness that impacts roughly 1 out of every 10 Americans. Depression can impact anyone regardless of age, race or economic status, but studies have shown that people with the following risk factors have a higher chance of depression:

  • Family history of depression, bipolar disorder or suicide
  • Those with excessive and inappropriate worry
  • Drug or alcohol abuse and addiction
  • Lack of self-esteem
  • Being lesbian, gay, bisexual or transgender
  • History of trauma or sexual abuse
  • Chronic, serious medical illnesses, including other psychiatric disorders
  • Stressful life events in the last year, financial problems; loss of a loved one.
  • Low education or lack of social support
  • History of divorce or marital problems
  • Certain medications (i.e., some high blood pressure medications, sedative medicines)

Depression tends to starts before age 30, but can happen at any time. Women appear to be at a higher risk, but may just be more likely to get a diagnosis.

The elderly are also at an especially high risk for depression, often compounded by chronic health conditions, loneliness, lack of social support, and limited mobility.

Symptoms and Diagnosis of Depression

The symptoms of depression can be highly variable from person-to-person. The most common sign of depression is a chronic, deep, severely low mood, profound sadness, tearfulness, or a sense of hopelessness. For some people, depression symptoms may include chronic irritability, anxiety or moodiness. Drug and alcohol abuse may co-occur.

To diagnose major depressive disorder you should have five or more of the following symptoms that occur every day, for most of the day, for at least two weeks in a row. At least one of these symptoms must be either depressed mood or loss of interest or pleasure:

  • Depressed mood: sad, empty or hopeless mood that lasts as least 2 weeks; may also feel anxious, irritated or upset.
  • Inactivity and withdrawal from usual activities; a loss of interest or pleasure in activities or friends that were once enjoyed.
  • A change in appetite, often with weight gain or loss.
  • Changes in sleep habits - either insomnia or sleeping too much
  • Restless and agitated OR physically and mentally slowed.
  • Fatigue and lack of energy.
  • Feelings of worthlessness, hopelessness, helplessness, self-hate, and inappropriate guilt.
  • Poor concentration, easily distracted, trouble making decisions.
  • Thoughts or actions of death or suicide.

When you visit your doctor, she or he will evaluate your:

  • Medical and mental health history
  • Physical and mental symptoms
  • Response to previous treatments (if any)
  • Work and social factors
  • Substance use history (illicit drugs and alcohol)
  • Family history of depression or other psychiatric illnesses
  • Any major life events, such as a recent job loss, family death or divorce.
  • History of suicidal thoughts, plans or actions.

Your doctor will also do a physical and mental health exam. You may need to have diagnostic tests, such as blood tests, to rule out any medical conditions that may lead to symptoms of depression. You should discuss your preferences for the treatment plan with your doctor, including medications and psychotherapy (talk therapy), limitations to your successful therapy, and any cost or insurance concerns you may have.

Depression Symptoms in Children, Teens and Seniors

In children, teens and the elderly, symptoms can be similar to adults, but with some differences.

  • Younger children may show signs of sadness, irritability, neediness, worry, aches and pains, school avoidance, or weight loss.
  • Teen symptoms may include sadness, irritable, low self-esteem, anger, lack of social interaction, poor school performance, illicit drug or alcohol use, changes in sleeping or eating patterns, and self-harm.
  • Depression is not a normal part of growing older and should be recognized and treated. Older patients may exhibit memory problems, physical complaints, chronically tired, loss of appetite, no social interaction, suicidal thoughts (especially in older men).

Subtypes of Depressive Disorders

Depression is not a one-size-fits all illness. There are different types of depression, some are more serious than others, but all of them may lead to a reduced quality-of-life. Sometimes depression can be a symptom of another serious medical issue, too, as outlined below:

  • Major Depression (also called major depressive disorder): A mood disorder in which feelings of sadness, loss, anger, or frustration interfere with everyday life for weeks, months or even a lifetime.
  • Dysthymia or persistent depressive disorder: Dysthymia is a chronic type of depression in which a person's moods are regularly low. However, symptoms are not as severe as with major depression.
  • Seasonal Affective Disorder (SAD): A depressive mood disorder that occurs and disappears at roughly the same time each year. The most common type is winter depression and it is characterized by excess morning fatigue, low energy, increased appetite and weight gain, and a craving for carbohydrates, all of which remit in the spring. Changes in seasons and reduced exposure to sunlight can trigger this this type of depression.
  • Depressive Psychosis: Depressive psychosis is a combination of a depressed mood along with psychosis, or a loss of touch with reality. The person may have delusions (false beliefs) or hallucinations (seeing or hearing things that are not there).
  • Bipolar disorder: It's sometimes difficult to distinguish between bipolar disorder and depression. An accurate diagnosis is important as treatments are different for bipolar disorder and major depressive disorder. Includes mood variation that swing from highs (mania) to lows (depression). 
  • Postpartum Depression: Women with postpartum depression may be restless, anxious, fatigued, irritable, tearful and feel inadequate. The mother may have a lack of interest or negative feelings towards the baby. Hormonal changes after the birth of a child may contribute to postpartum depression.
  • Premenstrual Dysphoric Disorder (PMDD): In PMDD, extreme mood shifts may start to occur in women beginning seven to 10 days before their period starts and may continue into the first few days of the period. Other typical symptoms that occur during a period, like breast tenderness, bloating, fatigue, and appetite changes may also occur, but the mood disorder is severe and may include symptoms such as sadness, anxiety, irritability, or aggravation. Hormonal changes may be the cause of some of the symptoms.
  • Cyclothymic disorder or mixed depression: In this type of depression, there is a mix of depression with manic symptoms, but not enough to classify as bipolar disorder. Symptoms may include: high self-esteem, excessive talking and elevated energy.
  • Depression with Anxiety: Anxiety, fears and worry are prominent features of this subtype of depression.

These types of mental health disorders do not usually go away on their own; seek advice and treatment from a qualified healthcare provider. Talk therapy and medication may be needed, and treatments may differ depending upon the diagnosis and severity of your symptoms.

Suicide Warning Signs

Depression may also involve thoughts of suicide. Those who are actively contemplating suicide need immediate medical professional help.

Learn to recognize these warning signs:

  • Thoughts of hurting or killing oneself
  • Feeling like there is no reason to live
  • Hopelessness
  • Looking for ways to kill yourself; making a plan
  • Talking about death, dying, or suicide
  • Self-destructive behavior such as use of drugs and alcohol, weapons

A person with symptoms of depression or thoughts of suicide should get immediate help from their healthcare provider, a trusted friend or family member, or call 911.

If you are with someone who is trying to attempt suicide, stay with that person and call 911 or your local emergency number immediately. If it is safe and you are able, you can also take the person to the closest hospital or emergency room.

Suicide Hotline

A confidential suicide hotline can be accessed in the U.S. by calling:

  • 1-800-273-TALK (1-800-273-8255) 24 hours a day, 7 days a week, or online at Trained, skilled professionals are available to to confidentially discuss any matter.

All antidepressants in the U.S. contain a Boxed Warning (similar to this one on Prozac) detailing risks of suicidal thoughts and behaviors.

  • In short-term clinical studies, antidepressants increased the risk of suicidal thoughts and behaviors in patients aged 24 years and younger.
  • These studies did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in patients over age 24 years.
  • In patients aged 65 years and older, there was a reduction in risk with antidepressant use.
  • All patients should be monitored closely for worsening of their depression and for emergence of suicidal thoughts and behaviors.
  • Remember that depression and other psychiatric problems are linked to suicide, as well. When depression is not treated, the risk of suicide can go up, too.

Call 911, a suicide hotline, or your doctor if...

  • You have thoughts of suicide, a suicidal plan, or thoughts of harming yourself or others.
  • You hear voices that are not there.
  • You have frequent crying spells with little or no provocation.
  • You have had feelings of depression that disrupt work, school, or family life for longer than two weeks.
  • You think that one of your current medications may be making you feel depressed. DO NOT change or stop any medications without consulting your doctor.
  • You believe that you should cut back on drinking, a family member or friend has asked you to cut back, you feel guilty about the amount of alcohol you drink, or you drink alcohol first thing in the morning.

Learn More - Slideshow: Depression, Risk of Suicide, & Treatment Options

Treatment Options for Depression

Depression can be treated in a variety of ways, particularly with medication and counseling. Some studies have shown that antidepressant drug therapy combined with psychotherapy appears to have better results than either therapy alone; most people seem to benefit from a combination of the two.

Medications for depression fall into several different classes and include:

  • Selective serotonin re-uptake inhibitors (SSRIs)
  • Serotonin norepinephrine reuptake inhibitors (SNRIs)
  • Atypical Antidepressants
  • Tricyclic antidepressants
  • Monoamine oxidase inhibitors
  • Miscellaneous antidepressants like the serotonin modulators

How to Control and Prevent Depression

  • Learning how to relax and manage stress.
  • Avoiding alcohol, drugs, and caffeine.
  • Exercising regularly.
  • Maintain good sleep habits.
  • Engage on a regular basis with family and friends.
  • Seek professional help early for symptoms of depression.
  • Stick to your depression treatment plan and medications if prescribed.

While antidepressant medications can be very effective, some may not be appropriate for everyone. Counseling may help you through times of grief, stress, or low mood.

Family therapy may be particularly important for teens who feel blue.

For the elderly or others who feel socially isolated or lonely, volunteering or getting involved in group activities may also help.

Medications and psychiatric counseling may prevent recurrences.