👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Psychosocial Integrity🔖 Free to read, print, and share
Also known as: depression · clinical depression · MDD · feeling depressed · major depression
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Use this quick-reference guide to spot, treat, and prevent Major Depressive Disorder on the NCLEX. Keep it handy during review and on exam day!
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📒 The 1-minute cheat sheet
🩺 Signs
SIG E CAPS mnemonic
Anhedonia, ↓ mood, hopeless
Sleep/appetite change, fatigue
🧪 Meds
SSRIs 1st-line, 4–6 wks onset
ECT for severe / refractory
✅ Do
Assess suicide risk directly
Simple choices, build routine
🚩 Report
Sudden calm = may have a plan
Risk ↑ as energy returns
📚 Major Depressive Disorder — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Major depressive disorder is a mood disorder marked by at least two weeks of depressed mood or loss of interest/pleasure (anhedonia) plus other symptoms that impair daily functioning. It involves dysregulation of serotonin, norepinephrine, and dopamine. Memory aid SIG E CAPS: Sleep changes, loss of Interest, Guilt/worthlessness, low Energy, poor Concentration, Appetite changes, Psychomotor changes, Suicidality.
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Key points
Understand these first
Core features are depressed mood and anhedonia lasting at least two weeks, most of the day nearly every day.
Vegetative signs include insomnia or hypersomnia, appetite/weight change, fatigue, and psychomotor agitation or retardation.
Feelings of worthlessness, excessive guilt, hopelessness, and difficulty concentrating are common.
Suicidal ideation is a hallmark concern and must be directly assessed.
Risk of suicide can paradoxically rise as energy returns early in treatment before mood fully lifts.
Antidepressants (SSRIs first-line) take 2 to 6 weeks for full therapeutic effect.
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Nursing priorities
What to do, in order
Assess directly for suicidal ideation, plan, means, and intent at every contact and ensure safety first.
Establish a trusting relationship and spend time with the client even when they are withdrawn or silent.
Promote basic needs: nutrition, hydration, sleep hygiene, and personal hygiene/ADLs.
Set small achievable goals and gradually increase activity to counter psychomotor slowing.
Monitor for the lag period of antidepressants and watch closely as energy returns.
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Red flags — report now
Escalate immediately
A client who suddenly becomes calm, gives away possessions, or has increased energy after starting antidepressants may have decided on suicide.
Verbalized plan, intent, or access to lethal means requires immediate one-to-one observation and provider notification.
Serotonin syndrome (hyperthermia, agitation, hyperreflexia, diaphoresis) from SSRI use must be reported immediately.
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Labs & values
Numbers to know
TSH 0.4-4.0 mIU/L to rule out hypothyroidism mimicking depression
Vitamin B12 200-900 pg/mL to rule out deficiency
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Patient teaching
What patients must know
Take antidepressants consistently and do not stop abruptly; full effect takes several weeks.
Avoid alcohol and report any worsening mood or suicidal thoughts immediately.
Report symptoms of serotonin syndrome and avoid combining with other serotonergic drugs without provider approval.
❓ Major Depressive Disorder: NCLEX FAQs
What are the priority nursing interventions for Major Depressive Disorder?
Assess directly for suicidal ideation, plan, means, and intent at every contact and ensure safety first. Establish a trusting relationship and spend time with the client even when they are withdrawn or silent. Promote basic needs: nutrition, hydration, sleep hygiene, and personal hygiene/ADLs. Set small achievable goals and gradually increase activity to counter psychomotor slowing.
What are the warning signs of Major Depressive Disorder a nurse must report?
A client who suddenly becomes calm, gives away possessions, or has increased energy after starting antidepressants may have decided on suicide. Verbalized plan, intent, or access to lethal means requires immediate one-to-one observation and provider notification. Serotonin syndrome (hyperthermia, agitation, hyperreflexia, diaphoresis) from SSRI use must be reported immediately.
What do I need to know about Major Depressive Disorder for the NCLEX?
Core features are depressed mood and anhedonia lasting at least two weeks, most of the day nearly every day. Vegetative signs include insomnia or hypersomnia, appetite/weight change, fatigue, and psychomotor agitation or retardation. Feelings of worthlessness, excessive guilt, hopelessness, and difficulty concentrating are common. Suicidal ideation is a hallmark concern and must be directly assessed.
What patient teaching is important for Major Depressive Disorder?
Take antidepressants consistently and do not stop abruptly; full effect takes several weeks. Avoid alcohol and report any worsening mood or suicidal thoughts immediately. Report symptoms of serotonin syndrome and avoid combining with other serotonergic drugs without provider approval.
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Quick Tip
Core features are depressed mood and anhedonia lasting at least two weeks, most of the day nearly every day.