Depression – medical revision notes
In this article we will describe 10 medical revision notes about depression.
Key Points
- Depression is a common mental disorder. 15% of adults suffer from significant depression, and more women than men
- It is characterised by sadness severe enough or persistent enough to interfere with function with decreased interest or pleasure in activities
- Exact cause is unknown – probably involves heredity, neurotransmitter levels, altered neuroendocrine function, and psychosocial factors
- Diagnosis is based on history
- Treatment usually consists of medication, psychotherapy, or both; and sometimes electroconvulsive therapy (ECT) or rapid transcranial magnetic stimulation (rTMS). Treatment is very effective for mild, moderate and severe depression
- Depression can lead to suicide.
1. Definition
- Depression is more than just feeling sad or low occasionally—it is a clinical syndrome with distinct, predictable symptoms
- It is a serious condition that affects both physical and mental health, going beyond temporary mood fluctuations.
2. Epidemiology
- Prevalence: Around 15% of adults experience significant depression
- Antidepressant use: Over 8 million people in the UK (12% of the population) are on antidepressant medication
- Disability: Depression is the leading cause of disability in the UK
- Age of onset: Most commonly begins in people aged 20-30 but can occur at any age
- Gender difference: Depression is more common in women, with a female-to-male ratio of 2:1.
Despite these challenges, depression is highly treatable, and with time and the right support, most people recover.
3. Risk factors
Risk factors for depression can be personal, medical, or situational:
- Genetic predisposition: A family history of depression can increase the risk, though it doesn’t guarantee that someone will develop the condition
- Personality traits: Individuals prone to worry, low self-esteem, perfectionism, or self-criticism are more vulnerable
- Chronic medical conditions: Long-term illnesses or chronic pain can trigger depression
- Substance abuse: Alcohol and drug misuse can both lead to and result from depression
- Life stressors: Persistent life difficulties (e.g., unemployment, relationship issues, social isolation) or significant adverse events (e.g., job loss, divorce, serious illness) can also trigger depressive episodes.
4. Causes
Depression typically results from a combination of biological, psychological, social, and lifestyle factors. Whilst the exact cause is unknown, several hypotheses exist:
- Monoamine hypothesis: Depression is thought to be linked to reduced levels of key neurotransmitters such as serotonin, dopamine, and noradrenaline in the brain. However, this is an oversimplification, as depression likely involves more complex brain processes.
5. Symptoms
A patient with depression may exhibit a variety of emotional, cognitive, behavioural, and physical symptoms.
- Emotional symptoms
- Persistent sadness, irritability, guilt, or frustration
- Feelings of worthlessness, hopelessness, or failure
- Suicidal thoughts (which should be taken seriously).
- Cognitive symptoms:
- Poor concentration, indecisiveness, and memory problems
- Negative thinking patterns, such as “I’m a failure,” “Life isn’t worth living.”
- Behavioural symptoms
- Withdrawing from friends and family
- Loss of interest in hobbies and usual activities
- Reliance on alcohol or drugs.
- Physical symptoms
- Fatigue, frequent headaches, muscle pain, gastrointestinal issues.
- Changes in appetite or weight.
- Sleep disturbances, such as insomnia.
6. Diagnosis
- Diagnosis is based on clinical history, with emphasis on identifying the above symptoms
- DSM-5 criteria for major depressive disorder (MDD) are often used to confirm the diagnosis
- There must be significant impairment in social, occupational, or other functional areas to distinguish depression from ordinary mood changes.
Differential diagnoses
- Demoralisation or grief (which may mimic depression)
- Anxiety disorders (often co-exist with depression)
- Bipolar disorder (must be distinguished from unipolar depression).
7. Treatment
Key principles
- Treatment works: Depression is highly treatable
- Medication: Antidepressants are effective; treatment is often trial and error to find the right drug
- Time: Depression improves with time, and time off work may be necessary, especially if work contributes to the condition
- Suicidal ideation: Any expression of suicidal thoughts requires urgent intervention
- Talking therapy: Encourage patients to talk about their experiences with trusted individuals or professionals.
Self-help strategies
- Encourage self-care: Maintaining a healthy diet, exercising, and establishing a daily routine can help alleviate symptoms
- Talking therapies: Available through the NHS (IAPT). Options include cognitive-behavioural therapy (CBT), psychodynamic therapy, group therapy, and counselling.
Medication
- SSRIs: (e.g., citalopram, fluoxetine, sertraline)
- SNRIs: (e.g., venlafaxine, duloxetine)
- Tricyclics and MAOIs: Used less frequently due to side effects.
Electroconvulsive therapy (ECT): Reserved for severe, treatment-resistant cases or life-threatening depression.
8. Complications
Depression can significantly impair a person’s social and occupational functioning, increasing the risk of:
- Substance misuse
- Poorer outcomes in coexisting medical conditions
- Morbidity and mortality, including a tenfold increased risk of suicide compared to the general population.
9. Prognosis
Most patients recover fully within 12 months, though depressive episodes typically last 3-6 months with treatment.
10. Prevention
No proven preventive measures exist, but patients can be advised to:
- Manage stress – effectively and maintain resilience.
- Open up – to trusted individuals about their feelings.
- Seek medical support – early to prevent the worsening of symptoms.
- Commit to long-term treatment – to reduce the risk of recurrence.
Other information
NHS Services for Depression
Primary mental healthcare:
- GP: Patients can ask to see a GP with a special interest in mental health.
- IAPT: Access to NHS talking therapies (self-referral or GP referral).
Secondary mental healthcare:
- Psychiatrist: For more complex or treatment-resistant cases.
- Mental Health Crisis Team (MHCT): For urgent psychiatric care, especially in cases of suicidal ideation or psychosis.
Mobile phone apps for depression
These can be very helpful in depression.
- Calm: https://www.calm.com
- Calm Harm – Self Harm: https://stem4.org.uk/new-calm-harm-app-features
- Stay Alive: https://www.stay-alive-app
- Virtual Hope Box: https://www.my-therappy.co.uk/app/virtual-hope-box
- Worry Tree: https://www.nhs.uk/apps-library/worrytree
Urgent mental health support for depression (especially if suicidal)
- Accident and Emergency (A&E) Department – call 999 or go there
- Call NHS 111 for physical or mental health emergencies (available 24/7)
- Samaritans: call 116 123 (available 24/7)
- SHOUT 85258: text ‘SHOUT’ to 85258 (available 24/7).
Conclusion
Depression is a complex but treatable condition. Medication is very effective. Early intervention, proper management, and a supportive approach are crucial to recovery.
Summary
We have described 10 medical revision notes about depression. Time is a great healer, and medication is powerful and very effective. Not all patients need medication. For them, talk therapy can be effective. There is alot the patient and the NHS can do to help get better.
Other resources
10 facts and figures about anxiety
This is good information from the NICE website
This is good advice on lifestyle changes you can make from a NZ website
