Mental health · 29 October 2026 · 9 min read

Depression symptoms: how to recognize it and what next

Depression is not weakness or a bad attitude. It is a common, treatable condition with clear criteria, and most people who have it can get better with care. The hard part is often getting to a professional: shame, the idea that you should pull yourself together and worries about medicine all get in the way. Here is how to recognize it, what a provider checks first and which treatments have the best evidence.

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In short

A depressive episode means low mood or loss of interest or pleasure most of the day, nearly every day, for at least two weeks, along with other symptoms such as poor sleep, low energy and trouble concentrating.
Some medical conditions and medicines can look like depression, so a provider checks for them first.
Psychological treatments are first-line, and antidepressants can be added for moderate and severe depression.
Antidepressants usually take one to two weeks to start working and up to eight weeks to work fully, and they should not be stopped suddenly.
If you have thoughts of ending your life, call or text 988 now.

How depression differs from a bad mood

Everyone has low days. NIMH says depression is more severe and lasts longer, and it affects how you feel, think and handle daily tasks such as sleeping, eating and working. WHO describes a depressive episode as low mood (sadness, irritability, emptiness) or loss of interest or pleasure, most of the day, nearly every day, for at least two weeks.

Mood and thinking: persistent sadness, hopelessness, guilt, low self-worth, trouble concentrating, difficulty making decisions, irritability or anxiety.
Body: changes in appetite or weight, disrupted sleep (too little or too much), fatigue, slower movement or speech, unexplained aches and pains.
Behavior: pulling back from friends, dropping hobbies, struggling at work or home, or using more alcohol or drugs.
Thoughts of death or suicide.

MedlinePlus notes that symptoms can look different by age and sex: children may seem irritable, and men may seem angry rather than sad. WHO also classes episodes as mild, moderate or severe, by the number and severity of symptoms and their effect on daily life.

What to rule out first

MedlinePlus explains that certain medicines and medical conditions, such as viral illnesses and thyroid disorders, can cause depression-like symptoms, and providers may order a physical exam and medical tests to rule them out.

Depression is also closely tied to physical health. WHO says people with conditions such as cardiovascular disease, cancer, diabetes and respiratory disease can develop depression, and shared risks such as physical inactivity and harmful alcohol use can drive both.

A provider will also ask whether you have had periods of unusually high energy or elevated mood. WHO explains that in bipolar disorder, depressive episodes alternate with manic symptoms, and it is treated with different medicines and approaches.

What works

WHO calls psychological treatments the first-line option for depression. They can be combined with antidepressants for moderate and severe depression, and antidepressants are not needed for mild depression.

Behavioral activation, cognitive behavioral therapy, interpersonal psychotherapy and problem-solving therapy are the effective psychological treatments WHO lists. They can be delivered in person, online or through self-help materials.
Antidepressants: a common class is the selective serotonin reuptake inhibitors, or SSRIs. WHO says antidepressants should not be used for depression in children and are not first-line in adolescents.
Brain stimulation: MedlinePlus lists electroconvulsive therapy, most often used for severe cases, and repetitive transcranial magnetic stimulation as options for severe or treatment-resistant depression.
Light therapy: MedlinePlus says it is effective for seasonal affective disorder.

MedlinePlus points out that depression often needs long-term treatment, usually medication, psychotherapy or both.

Antidepressants: what to expect

The NHS says antidepressants likely affect brain chemicals such as serotonin and noradrenaline. They usually take one to two weeks to start working and up to eight weeks to work fully, and treatment usually continues for at least six months after you feel better.

Side effects are common early on, and many ease after a couple of weeks. They can include sleep problems, nausea, headaches, dry mouth and sexual problems. The NHS adds that suicidal thoughts are uncommon but can occur when starting treatment, particularly in people aged 24 or under or with previous such thoughts, and that you should contact your doctor straight away if it happens.

Stopping suddenly can cause withdrawal symptoms such as dizziness, headaches, sleep problems and "brain zaps". The NHS advises agreeing a plan with your doctor to reduce the dose gradually. MedlinePlus adds that you may need to try more than one antidepressant before finding one that works.

What you can do yourself

WHO suggests the following steps alongside treatment, not instead of it.

Keep doing activities you enjoy and stay in touch with family and friends.
Exercise regularly, even briefly, and keep consistent eating and sleeping routines.
Avoid or reduce alcohol, and avoid illicit drugs, which can worsen depression.
Talk to someone you trust, and contact a health care provider.

How to support someone

Ask how they are, and listen without trying to fix everything. Encourage them to see a provider, offer to help book the appointment or go along, and stay in touch. Pulling out of social life is a symptom, not a rejection of you.

If they talk about death or suicide, take it seriously. Stay with them, help them reach a trusted person, a health worker or the 988 Suicide & Crisis Lifeline, and call 911 if they are in immediate danger.

When to see a doctor and red flags

The NHS advises seeing a doctor if symptoms last most of the day, every day, for more than two weeks. WHO notes that in high-income countries only about one third of people with depression receive treatment, with stigma among the barriers, so do not wait for it to pass.

Red flags: call or text 988 if you have thoughts of ending your life or harming yourself, and call 911 if you or someone else is in immediate danger. NIMH lists both numbers.

Questions to bring:

Could a medical condition or a medicine be contributing?
Which talking therapy is available to me, in person or online?
Do I need medicine, and what side effects should I watch for?
How long will treatment last, and how do we stop it safely?

Questions and answers

How long do symptoms need to last to count as depression?

Both WHO and the NHS point to at least two weeks of symptoms most of the day, nearly every day. Shorter low spells can happen to anyone and often lift on their own.

Can depression be treated without medicine?

Often, yes. WHO says antidepressants are not needed for mild depression, and psychological treatments such as cognitive behavioral therapy are first-line. For moderate and severe depression, a provider may combine therapy with medicine.

Do men and women show depression differently?

Sometimes. According to MedlinePlus, men may look angry rather than sad, and WHO reports that depression is about 1.5 times more common in women.

When will I feel better on antidepressants?

Often within one to two weeks you may notice a first change, with the full effect taking up to eight weeks, according to the NHS. If side effects are hard to bear, ask your provider before changing anything.

What should I do if I have thoughts of suicide?

Reach out right away: call or text 988, or chat at 988lifeline.org, and call 911 if you are in immediate danger. Telling a trusted person is a good step too.

Sources

Sources checked on 29 October 2026.