Depression – causes, symptoms and treatments

What is depression?

Depression is a mental health condition marked by persistent sadness or low mood that lasts for weeks or months, rather than just a few days. It often involves losing interest or pleasure in things you usually enjoy and can be accompanied by physical symptoms such as fatigue or poor sleep. 

Everyone feels down at times, but depression is different. It affects how you think, feel, and behave, and can interfere with daily life, work, and relationships. 

There are several types of depression, including: 

• Clinical depression (major depressive disorder): The most common form, involving continuous low mood and loss of interest. 

• Persistent depressive disorder (dysthymia): Long-term low mood lasting for two years or more. 

• Postnatal depression: Depression that develops after giving birth. 

• Seasonal affective disorder (SAD): Depression linked to seasonal changes, often worse in winter months. 

If you’re unsure whether you’re experiencing depression or simply going through a difficult time, it’s important to speak to your GP for assessment and advice.

What causes depression?

Depression doesn’t usually have one single cause. It can result from a combination of biological, psychological, and social factors. Understanding these can help you identify possible triggers and develop strategies to manage them. 

Common contributing factors include: 

• Life events: Bereavement, relationship breakdowns, financial stress, or job loss can all trigger depressive episodes. 

• Biological factors: Changes in brain chemistry, hormone levels, or family history of depression can increase vulnerability. 

• Personality traits: People who are more self-critical, have low self-esteem, or are prone to worry may be at higher risk. 

• Physical illness: Long-term health conditions such as chronic pain, heart disease, or diabetes can contribute to low mood. 

• Substance use: Alcohol and drug misuse can both trigger and worsen symptoms of depression. 

While you can’t always prevent depression, recognising early warning signs and making positive lifestyle changes can help reduce risk. 

What are the symptoms of depression?

Depression can affect you in many ways – emotionally, physically, and behaviourally. Symptoms can vary from mild to severe and may develop gradually. 

Emotional and psychological symptoms may include: 

• Persistent low mood or sadness 

• Loss of interest or pleasure in activities 

• Feelings of hopelessness or guilt 

• Difficulty concentrating or making decisions 

• Thoughts of self-harm or suicide 

Physical symptoms can include: 

• Changes in appetite or weight 

• Fatigue or low energy 

• Sleep problems – such as difficulty falling asleep or oversleeping 

• Slowed movement or speech 

• Unexplained aches or pains 

Behavioural and social changes might involve: 

• Withdrawing from family and friends 

• Reduced performance at work 

• Avoiding social situations 

• Neglecting hobbies or self-care 

If symptoms last more than two weeks or begin to interfere with daily life, it’s important to seek professional help.

How depression is managed

As depression can have different causes and symptoms, there are also different methods of treatment. It can be effectively treated with the right combination of approaches, which may include talking therapies, medication, lifestyle changes, or a mix of these. Your GP will help identify the best treatment plan based on your symptoms and personal preferences. 

Talking therapies

Cognitive behavioural therapy (CBT) is one of the most effective treatments for depression. It helps you identify and change negative thinking patterns that can contribute to low mood. Other options include counselling, interpersonal therapy (IPT), and group therapy. 

You can access talking therapies through your GP, privately, or by self-referring to NHS Talking Therapies. 

Medication

Antidepressant can work by acting on neurotransmitters that affect mood regulation and emotions. The most commonly prescribed types include: 

• SSRIs (selective serotonin reuptake inhibitors): Such as sertraline, fluoxetine, and citalopram. 

• SNRIs (serotonin-noradrenaline reuptake inhibitors): Such as venlafaxine or duloxetine. 

• Tricyclic antidepressants (TCAs): Such as amitriptyline, usually prescribed if other medicines haven’t worked. 

These medicines may take several weeks to have an effect, and your doctor will discuss possible side effects with you.

Lifestyle changes

Many people want to know how to manage depression naturally – making small adjustments to your lifestyle can complement medical or therapeutic treatment and improve recovery: 

• Stay physically active – exercise releases endorphins and may help reduce stress. 

• Eat a balanced diet with plenty of fruit, vegetables, and whole grains. 

• Maintain regular sleep patterns. 

• Limit alcohol and avoid recreational drugs. 

• Stay connected with family, friends, or support groups. 

Our Health Hub includes practical guides such as investing time into your physical and mental wellbeing for additional ideas on daily self-care.

When to seek further help

If you think you may be depressed, speak to your GP as soon as possible. They can help assess your symptoms using recognised tools like the PHQ-9 questionnaire and discuss appropriate treatment options. 

You should seek urgent help if you ever feel unable to keep yourself safe or have thoughts of self-harm or suicide. In an emergency, you can: 

• Call 999 or go to A&E 

• Call Samaritans on 116 123 (free, 24 hours a day) 

• Contact NHS 111 for urgent mental health advice 

• Reach out to a trusted friend, family member, or crisis helpline 

Living with depression

Recovery and long-term management of depression can take time, but with the right support, most people do improve. Learning to recognise triggers, maintaining healthy routines, and seeking help early can all support wellbeing. 

For ongoing support and expert advice, visit the Mental Health section of our Health Hub.