Major Depressive Disorder nursing care: what to assess and what to do first

Recognising it at the bedside

Look past low mood to the functional picture: anhedonia, disrupted sleep and appetite, psychomotor slowing or agitation, poor concentration, and a flattened affect that persists across the shift rather than fluctuating with events. Ask directly about duration — two weeks of most of the day, nearly every day, is the diagnostic threshold, and a patient who has felt this way for months will often minimise it as just how they are.

Somatic complaints are common presentations, especially in older adults and in patients from cultures where emotional language is less used: fatigue, vague pain, GI complaints, with no organic cause found. A nurse who screens only for stated sadness will miss a substantial proportion of major depressive disorder presenting this way.

Why the classic presentation misleads

The textbook image is a patient too withdrawn and low-energy to be a safety risk, and that image is exactly what makes the early recovery phase dangerous. The highest suicide risk is as the energy returns and the mood has not — which is why improvement is monitored more closely, not less. A patient newly started on an antidepressant, or moving out of the most severe phase of an episode, regains the physical and cognitive capacity to plan and act before the underlying hopelessness has lifted.

This is a specific, teachable trap: staff and families both tend to read "more energy, more talkative, eating again" as good news and relax vigilance at the exact point it should tighten. Depression severity and suicide capability move on different timelines, and nursing assessment has to track both, not just the one that's easier to see.

Priority nursing actions

Suicide risk assessment comes first, every shift, using a direct and specific question, not a euphemism, and documented rather than assumed unchanged from the last note. Ask about ideation, plan, means, and intent separately, since a patient can have thoughts without a plan or a plan without immediate intent, and the distinction changes the safety response.

Establish a safety plan and environment: remove or secure means, increase observation level if risk is elevated, and reassess at every mood or energy shift, not just at admission. Build rapport through consistent, low-demand presence rather than pushing conversation or forced activity, and validate the patient's experience without reinforcing hopeless statements as fact.

Encourage basic self-care, structured activity, and social contact at a pace the patient can tolerate, since withdrawal both signals and worsens the episode.

Labs and diagnostics to expect

There is no laboratory test that diagnoses major depressive disorder; diagnosis is clinical, against DSM-5-TR criteria. Labs are ordered to rule out or identify contributing medical causes: TSH and free T4 for hypothyroidism, CBC for anaemia, basic metabolic panel, vitamin B12 and folate, and a toxicology screen where substance use is suspected.

Standardised screening tools support and track severity rather than diagnose outright — PHQ-9 is the most widely used in general and primary care settings, with the Hamilton Depression Rating Scale more common in specialist or research settings. A rising or unchanged PHQ-9 score despite treatment is a prompt to reassess the plan, not just to repeat the tool.

Complications and their early signs

Suicide is the complication that drives the care plan, but it is not the only one. Watch for worsening functional decline — inability to maintain hygiene, work, or basic nutrition — which can progress to severe weight loss or dehydration in untreated cases. Psychotic features, present in a minority of severe episodes, show as mood-congruent delusions or hallucinations and change both risk level and treatment approach.

Substance use frequently co-occurs and can mask or worsen symptoms, so screen for it directly rather than assuming sobriety. Social withdrawal that isolates a patient from any support network is itself a risk multiplier, since it removes the people most likely to notice deterioration between clinical contacts.

Teaching that changes outcomes

Antidepressants typically take two to four weeks to show measurable effect and up to six to eight weeks for full effect, and patients who aren't told this often stop the medication early, believing it isn't working. Explain that side effects frequently appear before benefit does, which is the mismatch that drives non-adherence in the first weeks of treatment.

Teach the family or support person, not just the patient, to recognise the energy-before-mood pattern as a high-risk window rather than a recovery milestone, since they are often the ones present when it occurs. Reinforce that stopping medication abruptly risks discontinuation symptoms and relapse, and that any worsening of mood, new agitation, or emergence of suicidal thoughts after a medication change warrants immediate contact with the care team, not a wait-and-see approach.