Depression is a mental health condition marked by ongoing low mood that interferes with everyday functioning. It affects more than just emotions—it can influence how a person thinks, behaves, and experiences the world around them.

Also referred to as major depressive disorder, depression is one of the most widespread mental health conditions in the United States. According to the American Psychiatric Association, about one in six people will experience depression at some point in their lives, and roughly one in fifteen individuals are affected in any given year.

Many people experiencing depression may not realize that effective treatment options are available, both in-person and through telehealth. While it can feel overwhelming or even impossible to overcome, depression is a highly treatable condition with the right support.

Types of Depression

Major Depressive Disorder (MDD)
Major depression is a serious condition that can significantly impact daily life and overall functioning. It involves persistent feelings of sadness, hopelessness, and a loss of interest in activities that were once enjoyable. Symptoms typically last at least two weeks and can interfere with work, relationships, and routine responsibilities.

Common symptoms include:

• Changes in appetite

• Sleep disturbances

• Low energy or fatigue

• Feelings of guilt or worthlessness

• Trouble focusing

• Thoughts of death or suicide

Treatment often includes a combination of therapy (such as cognitive-behavioral therapy, interpersonal therapy, or psychodynamic therapy) and medications like SSRIs or SNRIs, which help regulate brain chemistry related to mood.

Persistent Depressive Disorder (PDD)
Previously known as dysthymia, this form of depression is more long-lasting, with symptoms persisting for two years or longer. While symptoms may be less intense than major depression, they tend to be ongoing and can still affect quality of life.

Treatment approaches are similar to those used for major depression and may include therapy, medication, lifestyle adjustments, and ongoing support.

Bipolar Disorder
This condition involves shifts between depressive episodes and periods of elevated mood (mania or hypomania). The depressive phases can resemble major depression, while manic episodes may involve increased energy, impulsivity, or unusually elevated mood.

Seasonal Affective Disorder (SAD)
SAD typically occurs during the fall and winter months when there is less natural sunlight. Reduced daylight can disrupt the body’s internal clock and contribute to depressive symptoms.

Treatment often includes light therapy, which involves exposure to a bright light source designed to mimic natural sunlight. Sessions usually last 30–45 minutes each morning during darker months. Therapy, medication, exercise, and maintaining a consistent routine can also be helpful.

Postpartum Depression (PPD)
This form of depression occurs after childbirth and can involve intense sadness, anxiety, and exhaustion. It is believed to be related to a combination of hormonal, emotional, and lifestyle changes. With appropriate treatment—including therapy and medication—symptoms can improve significantly.

Psychotic Depression
A more severe form of depression that includes symptoms of psychosis, such as hallucinations or delusional thinking. Treatment typically involves a combination of antidepressant and antipsychotic medications, along with therapy.

Premenstrual Dysphoric Disorder (PMDD)
PMDD is a severe form of premenstrual syndrome that causes emotional and physical symptoms strong enough to interfere with daily life. Symptoms occur in the days leading up to menstruation and typically improve once it begins.

Atypical Depression
This subtype includes symptoms such as increased appetite, excessive sleep, and a heavy feeling in the body. Unlike other forms of depression, mood may temporarily improve in response to positive events.

Situational Depression
Also known as adjustment disorder with depressed mood, this type is triggered by a specific life stressor, such as a loss, major transition, or significant change. It is usually temporary and improves as the individual adapts.

Treatment-Resistant Depression (TRD)
TRD refers to depression that does not respond to standard treatments like medication or therapy. In these cases, alternative options may be considered, including:

• Electroconvulsive therapy (ECT)

• Transcranial magnetic stimulation (TMS)

• Ketamine therapy

• Emerging treatments such as deep brain stimulation or psychedelic-assisted therapy

Close collaboration with a mental health provider is essential to identify the most effective approach.

Signs and Symptoms

Depression can present differently from person to person. Some individuals may feel persistently low, while others may experience irritability or a lack of motivation.

A diagnosis is typically considered when at least five of the following symptoms are present:

• Ongoing depressed mood

• Thoughts about death or suicide

• Loss of interest in activities

• Difficulty concentrating

• Changes in weight or appetite

• Feelings of guilt or worthlessness

• Sleep disturbances

• Low energy

• Slowed movements or restlessness

Other commonly reported experiences include anxiety, irritability, and appetite changes.

Depression can also be associated with physical symptoms, especially when combined with other medical or mental health conditions.

Depression Screening

Screening for depression involves a structured set of questions used by healthcare professionals to identify symptoms. These screenings are commonly used in primary care and mental health settings as an initial step in evaluating a person’s mental health.

Standardized tools—such as the PHQ-9 or Beck Depression Inventory—ask individuals to rate the frequency and severity of symptoms over a recent period, often the past two weeks. These assessments help guide diagnosis and treatment planning.