Depression: Symptoms, NHS Diagnosis & Treatment
Depression is one of the most common mental health conditions in the UK, affecting around 1 in 6 adults at any one time. It is more than feeling sad — it is a recognised medical condition that affects how you feel, think, and function. With the right support and treatment, most people with depression recover fully.
If you are experiencing depression, please speak to your GP. NHS talking therapies are available — many areas offer self-referral. If you are in crisis, contact Samaritans on 116 123 (free, 24/7) or NHS 111.
- UK prevalence: ~1 in 6 adults; more common in women
- NHS diagnosis tool: PHQ-9 (Patient Health Questionnaire)
- First-line treatments: Talking therapy (CBT), antidepressants, or both
- NHS Talking Therapies: Available for mild to moderate depression — self-referral in most areas
- Full recovery: Most people recover fully with appropriate support
Symptoms of Depression
Depression is characterised by persistent low mood or loss of interest lasting at least two weeks. Symptoms include:
- Persistent low mood, sadness, or emptiness
- Loss of interest or pleasure in activities you previously enjoyed (anhedonia)
- Fatigue and low energy
- Difficulty concentrating, remembering, or making decisions
- Sleep problems (insomnia or sleeping too much)
- Changes in appetite or weight
- Feelings of worthlessness, guilt, or hopelessness
- In severe cases, thoughts of self-harm or suicide
NHS Diagnosis
Your GP will typically use the PHQ-9 questionnaire to assess the severity of your symptoms and rule out other causes (such as thyroid problems or anaemia). Depression is classified as mild (PHQ-9: 5–9), moderate (10–14), moderately severe (15–19), or severe (20–27), which guides treatment decisions.
NHS Treatment Options
NHS Talking Therapies (formerly IAPT): Cognitive behavioural therapy (CBT) is the most evidence-based talking therapy for depression. You can self-refer online in most areas at nhs.uk/talking-therapies. Waiting times vary.
Antidepressants: Commonly prescribed SSRIs (selective serotonin reuptake inhibitors) such as sertraline or fluoxetine are first-line for moderate to severe depression. They typically take 2–4 weeks to have full effect and are usually taken for at least 6 months.
Combination treatment: For moderate-severe depression, combined therapy (talking therapy + medication) is often more effective than either alone.
Disclaimer: Educational information only. If you are concerned about your mental health, please speak to your GP. Full disclaimer →
Frequently Asked Questions
How long does NHS treatment for depression take to work?
Antidepressants typically take 4–6 weeks to show significant improvement. Talking therapies such as CBT usually involve 6–20 weekly sessions. Mild to moderate depression often improves within a few months. Severe or recurrent depression may take longer and require longer-term support.
How do I access NHS support for depression?
You can self-refer to NHS Talking Therapies (formerly IAPT) online at nhs.uk — no GP referral is needed. Your GP can also refer you, prescribe antidepressants, and monitor your progress. In a mental health crisis, contact 111, the Samaritans (116 123), or go to A&E.
What is the difference between feeling sad and clinical depression?
Feeling sad is a normal emotional response that typically improves over time. Clinical depression is a medical condition lasting two weeks or more, involving persistent low mood, loss of interest or pleasure in activities, changes in sleep and appetite, difficulty concentrating, and impaired daily functioning. It requires professional assessment and treatment.