Depression

Key Points

• Depression is a group of mood disorders characterized by a persistently depressed or irritable mood, loss of interest/pleasure (anhedonia), and associated cognitive and physical symptoms that impair functioning.
• Major Depressive Disorder (MDD): ≥5 of 9 DSM-5-TR criteria present for ≥2 weeks; at least one symptom is depressed mood OR anhedonia.
• Types: MDD, persistent depressive disorder (dysthymia), premenstrual dysphoric disorder (PMDD), postpartum depression, and seasonal affective disorder.
• Treatment: 80–90% of people with depression respond well to treatment — antidepressants, psychotherapy, ECT, TMS, and self-care.
• Priority assessment: suicide risk screening (PHQ-9, Columbia Suicide Severity Rating Scale); immediate provider notification for suicidal ideation with plan.
• Antidepressants: SSRIs are first-line; monitor for serotonin syndrome; MAOIs require tyramine dietary restrictions.
• In serious illness contexts, persistent hopelessness/helplessness or suicidality is not considered normal grief and requires urgent escalation.
• Depressive illness is a major global mortality-risk context; suicide contributes to over 700,000 deaths per year worldwide.
• Depressive burden is substantial and uneven: lifetime major-episode risk is higher in women than men, and many affected people still do not receive adequate treatment because of stigma and access barriers.

Pathophysiology

Depression involves dysregulation of neurotransmitters — particularly serotonin, norepinephrine, and dopamine — within the brain’s limbic system and prefrontal cortex. Neuroimaging studies show decreased activity in the prefrontal cortex and hippocampal volume loss in chronic depression.

Limbic-hypothalamic stress signaling is also relevant: increased amygdala activity can persist even after symptom improvement, and hypothalamic-pituitary-adrenal (HPA) axis dysregulation (CRH → ACTH → cortisol) can reinforce depressive symptom burden over time.

Additional neurotransmitter-pathway patterns are clinically relevant: dopaminergic dysregulation contributes to anhedonia, low serotonin-transmission metabolites are linked with higher suicide risk in some studies, and low inhibitory GABA signaling is associated with major depressive disorder.

In chronic stress states, feedback shutoff of fight-or-flight signaling may become inefficient, with persistently elevated cortisol and CRH burden. This pattern is associated with depression and broader cardiometabolic and immune strain; CRH reduction during effective treatment (including antidepressants or ECT when indicated) often parallels symptom improvement.

Medical and medication-related pathways are also clinically significant. A meaningful subset of depressive presentations is associated with underlying medical illness (for example thyroid dysfunction, cardiovascular disease after myocardial infarction, neurologic disorders, chronic pain, and selected infectious/inflammatory conditions). Medication/substance exposures can also worsen mood or precipitate depressive symptoms, including corticosteroids, some antihypertensives, selected antiepileptics, oral contraceptives, barbiturates, and heavy alcohol or cannabis use.

Risk factors: personal or family history of depression, trauma, chronic illness, substance use, hormonal changes, and social isolation.

Types of Depressive Disorders

Type	Duration	Key Features
Major Depressive Disorder (MDD)	≥2 weeks	5+ DSM-5-TR criteria; one must be depressed mood or anhedonia
Persistent Depressive Disorder (Dysthymia)	Adults: ≥2 years; children/adolescents: ≥1 year	Chronically depressed or irritable mood with lower-intensity but persistent symptoms
Postpartum Depression	Within 1 year of childbirth	Depressive episode triggered by hormonal changes postpartum; severe untreated episodes can progress to postpartum psychosis emergency
Premenstrual Dysphoric Disorder (PMDD)	Recurrent; luteal phase	Severe mood changes, irritability, and depression in week before menses
Seasonal Affective Disorder (SAD)	Seasonal pattern	Depression onset in fall/winter with spring improvement; affects about 5% of U.S. adults; responds to light therapy
Depressive Disorder Due to Another Medical Condition	Variable	Depressive symptoms are a direct physiologic consequence of another medical illness (for example endocrine, neurologic, autoimmune conditions)
Substance/Medication-Induced Depressive Disorder	Variable	Depressive syndrome emerges during use, intoxication, withdrawal, or medication exposure and requires temporal linkage review
Adjustment Disorder with Depressed Mood / Other Specified or Unspecified Depressive Disorder	Typically stressor-linked or subthreshold	Distress/impairment is present but full criteria for specific depressive disorders are not met

Peripartum Mood Disturbance Continuum

• Baby blues: Common transient postpartum mood lability (up to about 70% of new mothers), usually beginning within a few days after delivery and resolving within about 2 weeks without major functional impairment.
• Perinatal depression: Depressive symptoms during pregnancy or within 1 year postpartum; includes antenatal and postpartum phases and can impair maternal function, bonding, and family stability.
• Postpartum depression: A major depressive episode after birth, commonly recognized between 1-3 weeks postpartum but possible at any point in the first postpartum year.
• Untreated impact: Ongoing peripartum depression is associated with bonding disruption, infant sleep/feeding difficulties, and higher risk of later child cognitive, emotional, language, and social-development challenges.

DSM-5-TR Criteria for Major Depressive Disorder

Diagnosis requires 5 or more of the following 9 symptoms during the same 2-week period — at least one must be (1) depressed mood OR (2) anhedonia:

1. Depressed mood most of the day, nearly every day
2. Anhedonia — markedly diminished interest or pleasure in activities
3. Significant weight loss or gain (>5% body weight in a month) OR decreased/increased appetite
4. Insomnia or hypersomnia nearly every day
5. Psychomotor agitation or retardation (observable by others)
6. Fatigue or loss of energy nearly every day
7. Feelings of worthlessness or excessive guilt (not merely self-reproach)
8. Diminished ability to think or concentrate; indecisiveness
9. Recurrent thoughts of death, suicidal ideation without a specific plan, or a suicide attempt

Severity is often documented as mild, moderate, or severe based on symptom burden and functional impairment.

Suicidal Ideation — Immediate Action Required

Recurrent thoughts of death or suicidal ideation (item 9) requires immediate assessment of suicide risk. Active suicidal ideation with plan → notify provider immediately, initiate safety precautions.

Nursing Assessment

Mental Status Examination Findings in Depression

Component	Common Findings
Appearance	Disheveled, poor hygiene, unwashed, food-stained clothing
Behavior	Psychomotor retardation; avolition (reduced goal-directed behavior); social isolation
Mood/Affect	Apathy, sadness, flat or blunted affect, dysphoria, crying episodes, labile mood
Speech	Slow, monotone; latency (delayed response to questions)
Thought	Hopelessness, worthlessness, guilt, indecisiveness; recurrent thoughts of death
Sleep	Insomnia (<4 hours or interrupted sleep) OR hypersomnia (14–18 hours/day)
Appetite	Decreased (weight loss) or increased (weight gain)

Critical Findings — Notify Provider Immediately

• Verbal or nonverbal threats of harm to self or others
• Active self-harming behaviors (cutting, picking, head-banging)
• “Cheeking” medications (holding pills in mouth to save for later overdose)
• Suicidal ideation with a specific plan
• Hopelessness, worthlessness, or helplessness statements with escalating despair
• Suicidal, homicidal, or violence ideation; do not leave the client alone during active-risk statements while escalating care
• Sudden euphoric or markedly energized change after severe depression; this can indicate a high-risk suicide-attempt window rather than true recovery

Distinguishing Grief From Major Depression

• In grief, painful emotions often come in waves and may alternate with positive memories; in major depression, depressed mood/anhedonia is more persistent across most days.
• In grief, self-esteem is usually preserved; in major depression, worthlessness or self-loathing is common.
• Thoughts about death in grief may center on reunion fantasies with the deceased, whereas major depression more often involves self-harm themes linked to hopelessness or perceived burdensomeness.

Screening Tools

• PHQ-9 (Patient Health Questionnaire-9): 9-item validated tool based on DSM-5-TR criteria; scores 0–27; ≥10 = moderate depression; ≥20 = severe depression
• Edinburgh Postnatal Depression Scale: Validated for postpartum depression screening
• Before finalizing diagnosis/treatment plans, complete a full evaluation set (interview, mental status exam, psychosocial assessment, and medical screening for reversible causes such as thyroid disease or nutritional deficiency).

Depression in Children and Adolescents

• Ask directly about depression when youth are withdrawn or persistently sad for 2 or more weeks.
• Screen for pediatric-specific cues: school inattention, physical complaints (headache/stomachache), self-injury, substance use, and “acting-out” behavior.
• Ask directly about suicide or self-harm after acute interpersonal stressors (for example relationship break-up), because catastrophic interpretation can increase near-term risk.
• Review timeline links between mood change and medical illness, medication changes, dose changes, or substance-use escalation to identify potentially reversible contributors.
• In some cultural contexts, depressive mood may be reported primarily as physical complaints (for example pain, fatigue, weakness), so assess somatic narratives without dismissing mood disorder risk.
• Perform serial follow-up assessments against baseline admission findings (mental status, psychosocial, cultural, and spiritual domains) to detect trend-level deterioration or recovery.
• Use focused symptom questioning frameworks (for example PQRSTU) when clarifying depressive symptom onset, aggravating/relieving factors, severity, and client meaning.

Pharmacological Treatment

NCLEX Focus

SSRIs are first-line antidepressants. Key nursing priorities: (1) monitor for serotonin syndrome (SSRIs + SNRIs); (2) MAOIs require tyramine-restricted diet (no aged cheese, cured meats, wine); (3) antidepressants have delayed onset (initial change after 2+ weeks, often 4-8 weeks for noticeable mood effect) and this lag likely reflects downstream neuroplastic changes (for example hippocampal neurogenesis/synaptic remodeling), not immediate transmitter rise alone; (4) increased suicide risk in early treatment as energy can improve before mood lifts; (5) do NOT abruptly discontinue — taper to prevent discontinuation syndrome. In pediatric depression, FDA-approved SSRIs are fluoxetine (age 8 and older) and escitalopram (age 12 and older); monitor closely for emergent suicidality and behavior changes after initiation or dose adjustment.

Drug Class	Examples	Mechanism	Key Side Effects / Nursing Considerations
SSRIs (first-line)	Fluoxetine, Sertraline, Citalopram	Block serotonin reuptake at synapse	Sexual dysfunction, GI upset, insomnia, QTc prolongation; serotonin syndrome (with other serotonergic drugs)
SNRIs	Venlafaxine, Duloxetine	Block serotonin AND norepinephrine reuptake	Similar to SSRIs; also monitor blood pressure; weight gain
TCAs (Tricyclics)	Amitriptyline, Nortriptyline	Block norepinephrine (and partial serotonin) reuptake	Anticholinergic effects (tachycardia, urinary retention, constipation (constipation), dry mouth, blurred vision); orthostatic-hypotension (orthostatic hypotension); lethal in overdose
MAOIs	Phenelzine, Tranylcypromine	Block MAO enzyme → increases serotonin + norepinephrine	Hypertensive crisis with tyramine-rich foods; dangerous drug-drug interactions (avoid SSRIs, meperidine, stimulants)
Atypicals	Bupropion, Mirtazapine, Trazodone	Varied mechanisms	Bupropion: lowers seizure threshold; contraindicated in eating disorders; Mirtazapine: sedation, weight gain
NMDA receptor antagonist (treatment-resistant depression)	Intranasal esketamine	Glutamatergic modulation with rapid antidepressant effect	Considered after at least two antidepressant trials fail; often relieves symptoms within hours; given with an oral antidepressant and monitored in a supervised setting

Serotonin Syndrome — Emergency

Occurs when serotonergic medications are combined (e.g., SSRI + SNRI, SSRI + tramadol, SSRI + linezolid):

• Triad: Hyperthermia + neuromuscular abnormality (clonus, hyperreflexia, tremor) + altered mental status
• Action: Discontinue offending medications; supportive care; cyproheptadine (serotonin antagonist)

Non-Pharmacological Treatments

Treatment	Indication
Psychotherapy (CBT, IPT, MBCT, DBT, family/group-supportive pathways)	Mild depression can be treated with psychotherapy alone; moderate-to-severe episodes usually combine psychotherapy with medication (clinically meaningful gains are often seen over about 10-15 sessions)
Electroconvulsive Therapy (ECT)	Severe or treatment-resistant major depression, especially with urgent symptom burden; commonly delivered 2-3 times/week for about 6-12 treatments under anesthesia with informed-consent and peri-anesthesia monitoring
Transcranial Magnetic Stimulation (TMS)	Medication-resistant depression; targeted noninvasive outpatient neuromodulation (typical 30-60 minute sessions, no anesthesia)
Light therapy	Seasonal affective disorder; winter-onset pattern (typically 2,500-10,000 lux for 20 or more minutes, usually morning use)
Exercise and self-care	Adjunct for all severity levels

• Teach clients to avoid self-starting vitamin D or St. John’s wort for depression without provider review because these products are not FDA-approved for depression and may interact with prescribed medications.

Nursing Interventions

• Safety: Assess suicide risk at every encounter; implement falls precautions and environmental safety (remove sharps, ligature risks)
• Milieu safety operations: In higher-risk inpatient phases, use structured milieu routines and intentional rounding about every 15-60 minutes on a varied schedule to reduce predictability of safety checks
• Therapeutic relationship: Non-judgmental, empathetic communication; use therapeutic communication techniques
• Client-centered communication: Use clear jargon-free explanations, involve family/caregivers when appropriate, and align treatment choices with client preferences to improve adherence.
• Medication education: Explain delayed onset (often initial change after 2+ weeks and clearer mood benefit by about 4-8 weeks); do not stop abruptly; monitor for side effects; report increased suicidal thoughts during first weeks of therapy
• Medication administration safety: Open medications in front of the client and confirm ingestion when indicated to reduce paranoia and medication-hoarding/cheeking risk
• Maintenance planning: Reinforce continuation of antidepressant therapy for at least about 6 months after symptom remission; discuss longer maintenance in clients with high recurrence risk
• Phase-based recovery planning: Align interventions to active phase (about 6-12 weeks, symptom/function stabilization), continuation phase (about 4-9 months, relapse prevention), and maintenance phase (1 year or longer, recurrence prevention)
• Activity promotion: Encourage structured activity and exercise; combat anergia and avolition
• Nutrition support: Offer small frequent high-calorie/high-protein snacks and fluids, encourage social mealtimes, and monitor weight trends
• Sleep-rest support: Promote daytime activation and out-of-bed routine, then reinforce evening relaxation and caffeine avoidance
• Elimination support: Track bowel patterns and use hydration, fiber, activity, and bowel-regimen plans to prevent constipation/impaction
• Self-care support: Use step-by-step cueing for hygiene and grooming when psychomotor slowing or poor concentration limits task sequencing
• Interprofessional collaboration: Coordinate with psychiatrists, psychologists, social workers; refer to community mental health resources
• Brain-stimulation safety: For ECT, verify written informed consent, follow preprocedure fasting/medication instructions, and monitor airway-breathing-circulation, vital signs, cognition, and fall risk after anesthesia; reinforce that short-term memory effects are common and usually improve, though persistent gaps can occur
• TMS teaching: Explain noninvasive targeted stimulation, expected tapping sensation/headache, and rare seizure risk

Postpartum Psychosis Is an Emergency

Delusions, hallucinations, mania, paranoia, or severe confusion after delivery can indicate postpartum psychosis. Activate immediate emergency escalation (911/ED).

Related Concepts

• antidepressants — Pharmacological management of depression; SSRIs, SNRIs, TCAs, MAOIs drug classes.
• self-harm-and-suicide — Suicide risk assessment and safety planning are priorities in depressive disorder care.
• mental-health-and-mental-illness — Depression as one of the most common and treatable mental health disorders.
• therapeutic-communication — Therapeutic relationship and empathetic communication are foundational to nursing care for depressed clients.
• psychotropic-medications — Psychopharmacology overview including antidepressants in the context of psychiatric nursing.

Self-Check

1. A patient admitted for depression begins a new SSRI. After 5 days, family reports the patient “seems a little more energetic but still talks about wanting to die.” What is the priority nursing concern?
2. A patient on phenelzine (MAOI) asks if they can eat a salami sandwich and have a glass of red wine. How should the nurse respond?
3. What are the three components of serotonin syndrome, and which drug combinations commonly cause it?