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Depression – key points nurses need to know

Depression – key points nurses need to know
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Dr Peter Bagshaw
20 Apr 2026

Continuing our series highlighting recent presentations from Nursing in Practice 365 events, GP and former ICB mental health clinical lead Dr Peter Bagshaw provides an overview of the key points nurses working across primary and community care need to know about depression, including risk factors, symptoms and treatments.

The World Health Organization (WHO) defines depression as: ‘A common mental disorder characterised by a depressed mood or loss of pleasure or interest in activities for long periods of time. This condition is distinct from regular mood changes and feelings about everyday life.’

During a depressive episode, a person experiences a depressed mood and anhedonia: a loss of pleasure or interest in activities.

Other symptoms are also present, and may include:

  • poor concentration
  • feelings of excessive guilt or low self-worth
  • hopelessness about the future
  • thoughts about dying or suicide
  • disrupted sleep
  • changes in appetite or weight
  • feeling very tired or low in energy.

Possible evolutionary reasons for depression

Like many mental health conditions, depression is believed to be an exaggeration of a normal response. The psychic pain hypothesis suggests that depression may occasionally have a survival benefit, analogous to physical pain reducing injury. Several variants have been suggested, with the behavioural shutdown model suggesting ‘learned helplessness’ as a result of unavoidable stress.

Risk factors for depression

  • Genetics is a strong factor in depression: studies indicate major depression has around 40-50% heritability.
  • Gender is important, with a roughly 2:1 ratio of women versus men affected (though it has been suggested this may be partly due to under-reporting in men).
  • Stresses, especially if repeated, or childhood stresses known as ‘adverse childhood events’ correlate strongly with depression. This includes not just social stress but also physiological ones such as pregnancy or the menopause.
  • Drugs can play a part: not just recreational drugs and alcohol, but also some prescription drugs including anticonvulsants, statins, stimulants, benzodiazepines, corticosteroids and beta-blockers. Often people will self-medicate to dampen feelings, creating a vicious circle.
  • Neurotransmitter imbalance, though the serotonin hypothesis has been challenged recently, with some studies showing a lack of correlation between depression and serotonin levels.
  • Neuroinflammation has been recognised as a possibly important factor recently, arising from obesity, the gut microbiome, and infections such as Covid-19.
  • Coexisting illnesses: it is not surprising that other illnesses play a part, but the very high incidence reported in some conditions (for instance, up to 60% following a stroke) suggest there may be direct effects on the brain in some cases.

Should we screen for depression?

Until recently, this was done under QOF in certain patients with long-term conditions such as those with coronary heart disease. However, studies showed no improvement in outcomes, and the UK National Screening Committee does not currently recommend screening. However, being alert to cues, and asking screening questions in patients who are high risk (e.g. nursing home patients, those with coexisting disease) or where you have a clinical suspicion of depression, is important. In this situation, asking two simple screening questions is helpful:

  • ‘Do you feel down or depressed?’
  • ‘Have you lost interest in the things you normally enjoy?’

If they reply yes to either or both, it is worth following up with a more thorough set of questions. The most widely used currently in primary care (and embedded in most clinical systems) is the Patient Health Questionnaire-9 (PHQ-9).

Related Article: Nurses pushed to ‘breaking point’ by stress, survey reveals

Scoring not only gives a positive or negative outcome, but an idea of the severity of any depression present:

  • 0-4: None to minimal depression – The individual may not need treatment.
  • 5-9: Mild depression – Clinical judgement is advised regarding treatment based on symptom duration and functional impairment.
  • 10-14: Moderate depression – Treatment options may include therapy, medication, or a combination, depending on clinical judgment.
  • 15-19: Moderately severe depression – Treatment is generally warranted, often involving medication and/or psychotherapy.
  • 20-27: Severe depression – Immediate treatment is recommended, typically involving a combination of medication and therapy.

Note that for practical purposes, NICE has adopted a simplified approach and now defines depression as less severe (PHQ-9 score below 16) or more severe (PHQ-9 score 16 or over).

For treatment of less severe (<16 on PHQ9) depression, NICE recommends exercise and a talking therapy, especially CBT (cognitive behavioural therapy), as first-line therapy, with antidepressants ‘only if the patient has a clear preference’. Approved talking therapies are available through the NHS, often with self-referral, though waiting times can be an issue in some areas.

For more severe depression (PHQ-9 ≥16) talking therapies and/or antidepressants are recommended, though medication should be used with caution in under 25s due to the increased suicide risk (also a concern when patients first start taking antidepressants).

Any concerns about suicidal thoughts should prompt urgent referral, and treatment in bipolar disease, psychosis or borderline personality disorder requires specialist input. In terms of which medication to choose, NICE guidelines do not give advice on which antidepressant to use.

However, most would see SSRIs (selective serotonin reuptake inhibitors) as first-line, as they have fewer side-effects than older drugs. However, there are concerns over emotional blunting and withdrawal effects in some patients. There are differences among SSRIs such as half-life, and their sedating or stimulant effect. All take two weeks to have an effect, are fairly safe in overdosage and have similar risk profiles; if one is ineffective, switching to another is worth trying.

Venlafaxine and duloxetine are SNRIs (serotonin–norepinephrine reuptake inhibitors) which have slightly higher efficacy than SSRIs but also more side-effects. Mirtazapine is an atypical tetracyclic antidepressant, roughly as effective as SSRIs but causing drowsiness (paradoxically worse at lower dosage) and other side-effects.

Around 30% of severe depression does not respond to standard therapy, and NICE says there is still a place for ECT (electro-convulsive therapy) in such cases. In some areas TMS (transcranial magnetic stimulation) is available; it is a less invasive option with a 50-60% response. Vagal nerve stimulation is more invasive, and has a roughly 27% response. All are available through the NHS, though not in every area.

Other options for treatment resistant depression being investigated include:

St John’s Wort is specifically advised against by NICE, and online digital psychotherapy tools that use of Artificial Intelligence (AI) ‘chatbots’ in place of real psychotherapists have been found to make symptoms worse in some cases (though there are digital CBT programmes available through NHS talking therapies that are NICE-approved and effective).

Related Article: Public urged to speak to GP practices about talking therapies in new NHS campaign

Should you ask about suicidal thoughts?

NICE guidance is clear: ‘always ask people directly about suicidal ideation and intent’. The fear that asking about suicide might prompt it to happen has been debunked, and it is important as suicide in major depression is 8.6 times higher than in the general population.

A ‘no’ answer does not exclude thoughts of self-harm, but a ‘yes’ answer should always be taken seriously and prompt an urgent referral, immediate support (such as through Samaritans or the local Mindline) and a follow-up appointment, which has been shown to be the most effective intervention to reduce self-harm.

What’s different about depression in older people?

Depression is both the most common and most treatable mental illness in old age, affecting one in five older people in the community. This figure doubles in the presence of physical illness and trebles in hospitals and care homes.

Certain symptoms are more common in older adults and may be the only presenting features:

  • Reporting physical rather than emotional symptoms (somatisation). Typical symptoms are: faintness or dizziness, pain, weakness all over, heavy limbs, constipation.
  • Health anxieties (hypochondriasis), especially if unusual for the person.
  • Unusual behaviour. Hysteria does not exist in older people. (And remember delirium!)
  • Slowing down of emotional reactions or agitation.
  • Psychotic features or auditory hallucinations indicate depression, not psychosis.

Older people rarely present a diagnosis of depression, and if they feel low, will often attribute it to circumstance: asking about anhedonia (loss of enjoyment in everyday activities) can unmask this.

There is a myth that treatment is less effective: older people are rarely referred for talking therapies, but some evidence shows they do better than their younger counterparts when they are referred. They also respond equally well to medication, where sertraline or mirtazapine are recommended as they have less effect on the QT interval (‘start slow and go low’ is a useful mantra if medication is felt to be needed).

It can be difficult to distinguish between depression and dementia: both cause difficulties in concentration and memory. And of course, both are common, so may coexist. Speech and word-finding difficulties are suggestive of dementia rather than depression, but sometimes a trial of an antidepressant is needed to distinguish between them.

Some final take-home points:

Related Article: High levels of academic pressure increases risk of lasting depression, suggests study

  • Depression is common, especially in women, older people, those with a family history or with coexisting illness.
  • Screening is not recommended, but be alert to the possibility of depression and ask two simple screening questions.
  • If they suggest depression, use (and record) PHQ-9.
  • Always ask about suicide and take appropriate action.
  • If someone has mild to moderate depression, talking therapies are generally recommended over medication.
  • NICE guidelines give clear, evidence-based advice for all types of depression.
  • Older people may present with physical symptoms rather than obviously low mood. They respond well to both talking therapies and medication.

Dr Peter Bagshaw, GP, former ICB mental health clinical lead and co-author of ‘Mental Health in older people, a practice primer’

Sources and further information

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