Clinical depression can affect mood, sleep, energy, concentration, and everyday functioning. Getting help starts with an assessment; treatment can involve talking therapy, medication, or both. Use this guide to understand the options and prepare for a conversation with a professional.
Explore this guide
What Is Clinical Depression?
Clinical depression usually refers to major depressive disorder: depression that affects everyday functioning, rather than a brief change in mood. It can disrupt work, relationships, concentration, sleep, and the ability to enjoy things that previously mattered.
An assessment looks for a cluster of symptoms lasting at least two weeks, including depressed mood or loss of interest or pleasure. Diagnosis also considers how symptoms affect life and whether another condition could explain them. A difficult week or a questionnaire score alone does not settle the diagnosis.
- Mood and enjoyment
- Persistent sadness, emptiness, irritability, loss of interest, guilt, or worthlessness.
- Body and routine
- Changes in sleep, appetite, energy, movement, or the ability to keep up with everyday tasks.
- Thinking and safety
- Difficulty concentrating or making decisions, hopelessness, or thoughts of death or suicide.
Other depressive disorders can have different patterns or duration. NIMH’s depression guide describes persistent depressive disorder, seasonal depression, and other presentations. A clinician also asks about past periods of unusually elevated mood or energy because bipolar depression requires a different treatment approach.
Depression in the data
Major depressive episodes by age
Compare five years of U.S. survey estimates, and switch between all episodes and episodes that severely affected daily functioning.
2025 · any major depressive episode in the past year
Percentage of all adults in each age group. Severe-impairment estimates use the same population denominator; they are a subset of episodes, not an additional category.
NSDUH 2021–2025, U.S.
View all chart data and sources
NSDUH 2021–2025, U.S. civilian noninstitutionalized adults aged 18 or older. A major depressive episode is a survey classification for the past year, not a lifetime diagnosis. Severe impairment means a rating of at least 7 out of 10 in one or more assessed role domains. The 2021 estimates use revised weights from this report. Published standard errors are shown in percentage points, not as confidence intervals.
| Year | Measure | Age group | Estimate | SE (pp) |
|---|---|---|---|---|
| 2021 | Any major depressive episode | All adults (18+) | 8.5% | 0.22 |
| 2021 | Any major depressive episode | Ages 18–25 | 19.3% | 0.61 |
| 2021 | Any major depressive episode | Ages 26–49 | 9.6% | 0.33 |
| 2021 | Any major depressive episode | Ages 50+ | 4.5% | 0.29 |
| 2021 | Episode with severe impairment | All adults (18+) | 5.9% | 0.18 |
| 2021 | Episode with severe impairment | Ages 18–25 | 13.8% | 0.53 |
| 2021 | Episode with severe impairment | Ages 26–49 | 6.6% | 0.27 |
| 2021 | Episode with severe impairment | Ages 50+ | 3% | 0.25 |
| 2022 | Any major depressive episode | All adults (18+) | 8.8% | 0.20 |
| 2022 | Any major depressive episode | Ages 18–25 | 20.1% | 0.55 |
| 2022 | Any major depressive episode | Ages 26–49 | 9.7% | 0.31 |
| 2022 | Any major depressive episode | Ages 50+ | 4.6% | 0.30 |
| 2022 | Episode with severe impairment | All adults (18+) | 6.2% | 0.17 |
| 2022 | Episode with severe impairment | Ages 18–25 | 14.7% | 0.51 |
| 2022 | Episode with severe impairment | Ages 26–49 | 6.9% | 0.26 |
| 2022 | Episode with severe impairment | Ages 50+ | 3.1% | 0.26 |
| 2023 | Any major depressive episode | All adults (18+) | 8.5% | 0.20 |
| 2023 | Any major depressive episode | Ages 18–25 | 17.5% | 0.51 |
| 2023 | Any major depressive episode | Ages 26–49 | 10.2% | 0.29 |
| 2023 | Any major depressive episode | Ages 50+ | 4.5% | 0.29 |
| 2023 | Episode with severe impairment | All adults (18+) | 5.9% | 0.17 |
| 2023 | Episode with severe impairment | Ages 18–25 | 12.9% | 0.44 |
| 2023 | Episode with severe impairment | Ages 26–49 | 7.4% | 0.26 |
| 2023 | Episode with severe impairment | Ages 50+ | 2.7% | 0.24 |
| 2024 | Any major depressive episode | All adults (18+) | 8.2% | 0.18 |
| 2024 | Any major depressive episode | Ages 18–25 | 15.9% | 0.48 |
| 2024 | Any major depressive episode | Ages 26–49 | 10% | 0.30 |
| 2024 | Any major depressive episode | Ages 50+ | 4.4% | 0.28 |
| 2024 | Episode with severe impairment | All adults (18+) | 5.6% | 0.15 |
| 2024 | Episode with severe impairment | Ages 18–25 | 11.5% | 0.41 |
| 2024 | Episode with severe impairment | Ages 26–49 | 7% | 0.25 |
| 2024 | Episode with severe impairment | Ages 50+ | 2.6% | 0.22 |
| 2025 | Any major depressive episode | All adults (18+) | 7.4% | 0.20 |
| 2025 | Any major depressive episode | Ages 18–25 | 14.2% | 0.48 |
| 2025 | Any major depressive episode | Ages 26–49 | 9.1% | 0.32 |
| 2025 | Any major depressive episode | Ages 50+ | 4% | 0.26 |
| 2025 | Episode with severe impairment | All adults (18+) | 5.2% | 0.16 |
| 2025 | Episode with severe impairment | Ages 18–25 | 10.2% | 0.42 |
| 2025 | Episode with severe impairment | Ages 26–49 | 6.7% | 0.28 |
| 2025 | Episode with severe impairment | Ages 50+ | 2.5% | 0.19 |
Prepare for an assessment
A symptom list can help you describe what has changed. A clinician also considers timing, daily functioning, medicines, physical health, and other mental health conditions. NIMH explains the assessment process, including why an interview and sometimes medical tests are needed.
Compare treatment options
| Approach | What it involves | A useful question |
|---|---|---|
| Talking therapy | Sessions focused on thoughts, behavior, relationships, or emotional patterns. | What will we work on between appointments? |
| Medication | A prescriber selects a medicine and monitors response and side effects. | When will we review benefit, side effects, and dose? |
| Combined care | Therapy and medication coordinated around shared goals. | Who will oversee the plan and communicate changes? |
| Specialist treatments | Assessment for options such as brain stimulation when appropriate. | Why is this option being considered now? |
NIMH’s psychotherapy overview describes how therapy can be matched to a person’s needs. Ask how the proposed approach fits the problems you most want help with.
When specialist treatment enters the picture
If an adequate treatment trial has not helped, a specialist may reassess the diagnosis, change or combine treatments, or discuss options such as repetitive transcranial magnetic stimulation (rTMS) or electroconvulsive therapy (ECT). ECT can also be considered when a rapid response is needed in severe depression. NIMH’s brain-stimulation overview explains the procedures and how their uses differ.
Talking therapies
Cognitive Behavioral Therapy
Cognitive behavioral therapy (CBT) is a widely used talking treatment for depression and anxiety. It looks at how thoughts, feelings, and actions influence one another. Some people use it on its own; others combine it with medication.
The cognitive part helps you notice and examine interpretations that intensify distress. The behavioral part can include gradually returning to meaningful activities, tackling avoidance, or testing a different response to a difficult situation. Sessions usually connect to specific practice between appointments. Ask what you will work on and how progress will be reviewed.
Interpersonal Psychotherapy
Interpersonal psychotherapy (IPT) was developed at Yale University in the 1970s and has been effective in treating different forms of unipolar depression. IPT is time-limited psychotherapy with a focus on factors that form the basis of mental distress. This type of talk therapy normally takes anywhere from six to twenty sessions with follow-up maintenance sessions as they are needed.
IPT concentrates on improving your interpersonal functioning, resolving symptoms of depression, and increasing your social support system. The goal of the therapy is to improve your self-esteem and your communication skills in a short amount of time. The techniques used in interpersonal therapy include analyzing communication, examining interpersonal incidents, and role-playing.
Psychodynamic Psychotherapy
Psychodynamic psychotherapy explores emotional patterns, relationships, and experiences that may shape present difficulties, including feelings that are not immediately obvious. The aim is greater understanding and more flexibility in how you respond. Treatment may be brief and focused or longer term; ask about the proposed goals and schedule rather than assuming it is always open-ended.
Medication options
Antidepressants
Antidepressants affect signaling systems involved in mood, including serotonin, norepinephrine, and dopamine. Changes in these systems are part of research into depression, but the condition is not explained by a single proven chemical imbalance. Genetics, stress, physical health, and environment can also contribute.
Four established medication groups are outlined below. They are not the whole range: other antidepressants and specialist options also exist. A prescriber chooses among them using previous response, symptoms, side effects, other medicines, and your preferences. NIMH’s medication guide explains how treatment is monitored and adjusted.
Monoamine Oxidase Inhibitors
The first type of antidepressants to be developed were monoamine oxidase inhibitors. MAOIs have largely been replaced by other types of antidepressants that are safer and cause fewer side effects. MAOIs are still used by patients who experience no relief from other types of medication. Monoamine oxidase is an enzyme that helps remove norepinephrine, serotonin, and dopamine from your brain.
MAOIs make more of the neurotransmitters available in your brain by preventing the monoamine oxidase enzyme from removing them. The resulting improvement in cell communication is believed to cause a boost in mood. Common side effects of MAOIs include digestive problems, dry mouth, headache, sleep problems, and dizziness. MAOIs often react negatively with other medications.
Food and medicine interactions are especially important with MAOIs. Ask for the specific dietary restrictions, interaction checks, and switching plan for the prescribed product. Do not combine or switch antidepressants without the prescriber’s instructions.
Tricyclic Antidepressants
Tricyclic antidepressants were some of the first medications developed to combat depression, and they are still considered good options for treatment. Tricyclic antidepressants tend to relieve depression when other treatments are ineffective or can’t be used. TCAs work by blocking the reabsorption of the neurotransmitters norepinephrine and serotonin. This makes more of the chemicals available in your brain to send signals to cells, which can help relieve depressive symptoms.
The most common side effects of TCAs include blurred vision, dry mouth, drowsiness, constipation, weight gain, increased sweating, and a drop in blood pressure.
Selective Serotonin Reuptake Inhibitors
The most commonly used antidepressants are selective serotonin reuptake inhibitors. SSRIs are often considered before older antidepressants because of their overall tolerability, although response and side effects vary. These antidepressants are termed selective because they seem primarily to limit the reabsorption of serotonin and no other neurotransmitters in your brain. Common side effects of SSRIs may include nervousness, nausea, drowsiness, insomnia, dizziness, weight fluctuation, headache, and dry mouth.
Serotonin and Norepinephrine Reuptake Inhibitors
Serotonin and norepinephrine reuptake inhibitors block the reabsorption of the chemicals serotonin and norepinephrine, making these neurotransmitters more available and relieving depression. Possible side effects of SNRIs include dizziness, nausea, dry mouth, and excessive sweating.
If you’d like to learn more, consider reading our articles on the symptoms of depression.
Follow-up and progress
Agree on a follow-up plan when treatment begins. Useful markers include returning to an activity, managing daily tasks, sleep, and symptoms—not just whether a day felt “good” or “bad.”
| When | What to discuss |
|---|---|
| Starting treatment | The goals, expected benefits, possible side effects, and how to contact the service. |
| Early follow-up | Any new or worsening symptoms, difficulty taking medication, or barriers to attending therapy. |
| Reviewing response | What has changed, whether the plan needs adjustment, and the next review date. |
NIMH notes that antidepressants usually take 4–8 weeks to work; some changes can appear earlier. Ask your prescriber what to expect with your particular medicine and contact them about worsening symptoms rather than waiting for a scheduled review.
Clinical depression: common questions
How common is clinical depression?
In the 2025 NSDUH, 7.4% of U.S. adults had a major depressive episode in the past year. The estimate was 14.2% among ages 18–25, 9.1% among ages 26–49, and 4.0% among ages 50 and older. These are survey estimates of past-year episodes, not the percentage who have ever received a depression diagnosis.
What does “severe impairment” mean in the chart?
It is the survey’s measure of disruption to daily life. Respondents rate effects on home management, work, close relationships, and social life; a score of at least 7 out of 10 in any domain counts as severe impairment. In 2025, 5.2% of all U.S. adults had a past-year episode with severe impairment. That group is included within the 7.4% with any episode.
Do I need medication, therapy, or both?
Treatment choice depends on severity, prior response, other health conditions, access, and your preferences. Ask what the proposed option is expected to improve and when you will review it. Combined treatment can be appropriate, while therapy alone may suit some situations. There is no need to arrive having selected a particular drug or therapy yourself.
How long do antidepressants take to work?
A common timeframe is 4–8 weeks, according to NIMH’s medication guidance. Sleep, appetite, energy, or concentration may change before mood. Early follow-up still matters: report troublesome side effects, agitation, worsening symptoms, or suicidal thoughts promptly rather than waiting for the end of a trial.
What if the first treatment does not help?
Review what was tried, the dose or session schedule, how consistently it was possible to follow the plan, and the effects on everyday functioning. The clinician may adjust treatment, try a different approach, or investigate other contributing conditions. Bring a brief record of benefit and side effects; “nothing worked” is less informative than knowing which symptom changed and which did not.
Can I stop medication when I feel better?
Do not stop abruptly. Feeling better may mean treatment is helping, and stopping can cause withdrawal symptoms or a return of depression. Agree on how long to continue, when to review, and a gradual reduction plan if stopping becomes appropriate. Ask which symptoms during a reduction should prompt contact with the prescriber.
Can a blood test diagnose depression?
There is no routine blood test that establishes major depressive disorder. The diagnosis comes from clinical assessment. Tests may still help investigate other explanations or contributors, such as thyroid disease, depending on symptoms and history. Bring your medicine and supplement list as well as a description of what has changed.
Where can I start if I cannot find a therapist?
A primary care clinician can begin an assessment and discuss next steps. Ask about community services, telehealth, group treatment, and insurance-covered options. The federal FindTreatment.gov directory lists treatment services. Check availability and fees directly with the provider; a directory listing is not a guarantee of an appointment.