Depressive disorder, frequently referred to simply as depression, is more than just feeling sad or going through a rough patch. It’s a serious mental health condition that requires understanding and medical care. Left untreated, depression can be devastating for those who have it and their families. Fortunately, with early detection, diagnosis and a treatment plan consisting of medication, psychotherapy and healthy lifestyle choices, many people can and do get better.

Some will only experience one depressive episode in a lifetime, but for most, depressive disorder recurs. Without treatment, episodes may last a few months to several years.

About 21 million U.S. adults—8.4% of the population—had at least one major depressive episode in 2020. People of all ages and all racial, ethnic and socioeconomic backgrounds experience depression, but it does affect some groups more than others.

Personal Perspectives on Major Depressive Disorder

In this 2-part podcast series, NAMI Chief Medical Officer Dr. Ken Duckworth guides discussions on major depressive disorder that offer insights from individuals, family members and mental health professionals. Read the transcript.
Note: Content includes discussions on topics such as suicide attempts and may be triggering.

Symptoms

Depression can present different symptoms, depending on the person. But for most people, depressive disorder changes how they function day-to-day, and typically for more than two weeks. Common symptoms include:

• Changes in sleep
• Changes in appetite
• Lack of concentration
• Loss of energy
• Lack of interest in activities
• Hopelessness or guilty thoughts
• Changes in movement (less activity or agitation)
• Physical aches and pains
• Suicidal thoughts

Causes

Depression does not have a single cause. It can be triggered by a life crisis, physical illness or something else—but it can also occur spontaneously. Scientists believe several factors can contribute to depression:

• Trauma. When people experience trauma at an early age, it can cause long-term changes in how their brains respond to fear and stress. These changes may lead to depression.
• Genetics. Mood disorders, such as depression, tend to run in families.
• Life circumstances. Marital status, relationship changes, financial standing and where a person lives influence whether a person develops depression.
• Brain changes. Imaging studies have shown that the frontal lobe of the brain becomes less active when a person is depressed. Depression is also associated with changes in how the pituitary gland and hypothalamus respond to hormone stimulation.
• Other medical conditions. People who have a history of sleep disturbances, medical illness, chronic pain, anxiety and attention-deficit hyperactivity disorder (ADHD) are more likely to develop depression. Some medical syndromes (like hypothyroidism) can mimic depressive disorder. Some medications can also cause symptoms of depression.
• Drug and alcohol misuse. Adults with a substance use disorder are at significantly higher risk for experiencing a major depressive episode. Co-occurring disorders require coordinated treatment for both conditions, as alcohol can worsen depressive symptoms.

Diagnosis

To be diagnosed with depressive disorder, a person must have experienced a depressive episode lasting longer than two weeks. The symptoms of a depressive episode include:

• Loss of interest or loss of pleasure in all activities
• Change in appetite or weight 
• Sleep disturbances
• Feeling agitated or feeling slowed down
• Fatigue
• Feelings of low self-worth, guilt or shortcomings
• Difficulty concentrating or making decisions
• Suicidal thoughts or intentions

Treatments

Although depressive disorder can be a devastating illness, it often responds to treatment. The key is to get a specific evaluation and treatment plan. Safety planning is important for individuals who have suicidal thoughts. After an assessment rules out medical and other possible causes, a patient-centered treatment plans can include any or a combination of the following:

• Psychotherapy including cognitive behavioral therapy, family-focused therapy and interpersonal therapy.
• Medications including antidepressants, mood stabilizers and antipsychotic medications.
• Exercise can help with prevention and mild-to-moderate symptoms.
• Brain stimulation therapies can be tried if psychotherapy and/or medication are not effective. These include electroconvulsive therapy (ECT) for depressive disorder with psychosis or repetitive transcranial magnetic stimulation (rTMS) for severe depression.
• Light therapy, which uses a light box to expose a person to full spectrum light in an effort to regulate the hormone melatonin.
• Alternative approaches including acupuncture, meditation, faith and nutrition can be part of a comprehensive treatment plan.

Reviewed August 2017