About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- Depressed mood is a presentation, not a diagnosis: assess safety first, then separate MDD from bipolar disorder, grief, adjustment disorder, substances, and medical causes
- Always ask directly about suicidal ideation, self-harm, intent, plan, access to means, past attempts, protective factors, and supports
- Screen for mania/hypomania before prescribing an antidepressant — antidepressant monotherapy can precipitate mania or rapid cycling in bipolar disorder
- First-line management is severity-based: psychoeducation, behavioural activation, psychotherapy, antidepressants for moderate-severe or persistent depression, and urgent psychiatry for psychosis, catatonia, mania, or high suicide risk
- Baseline investigations are targeted: CBC/ferritin, TSH, B12, pregnancy test when relevant, medication/substance review, and assessment of comorbid anxiety, sleep disorder, pain, and trauma
Approach to the Presentation
Depressed mood on the MCCQE1 should be approached as a safety and diagnostic-sorting problem. Begin with immediate risk: suicide, self-neglect, psychosis, catatonia, intoxication, withdrawal, domestic violence, child-safeguarding concerns, and inability to care for dependants. Then characterize the syndrome: duration, anhedonia, neurovegetative symptoms, concentration, guilt, psychomotor change, functional impairment, trauma, bereavement, perinatal context, and previous episodes. The key diagnostic trap is missing bipolar depression: ask about distinct episodes of decreased need for sleep, increased energy, impulsivity, grandiosity, pressured speech, and risky behaviour. The Canadian approach is stepped and collaborative: measurement-based care, psychotherapy where available, CANMAT-aligned pharmacotherapy, active follow-up, and clear crisis planning.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Suicidal crisis / high-risk self-harm | must-not-miss | Depressed mood with active suicidal ideation, plan, intent, access to lethal means, recent attempt, intoxication, command hallucinations, hopelessness, or lack of supports | Structured suicide risk assessment + collateral history; do not rely on a screening score alone |
| Bipolar depression | must-not-miss | Depressive episode with past hypomania/mania, family history of bipolar disorder, antidepressant-induced activation, early onset, episodic course, psychotic features, or atypical hypersomnia/hyperphagia | Targeted bipolar history, Mood Disorder Questionnaire where useful, and collateral history |
| Psychotic depression | must-not-miss | Severe depression with mood-congruent delusions, hallucinations, profound guilt, nihilism, refusal to eat/drink, or marked psychomotor retardation | Mental status exam; urgent psychiatric assessment; consider inpatient care |
| Major depressive disorder | common | At least 2 weeks of depressed mood or anhedonia plus neurovegetative/cognitive symptoms causing functional impairment; no history of mania/hypomania | Clinical DSM-5-TR criteria + PHQ-9 for severity and monitoring |
| Adjustment disorder with depressed mood | common | Emotional symptoms within 3 months of identifiable stressor; distress out of proportion but full MDD criteria may not be met | Temporal link to stressor and reassessment if symptoms persist or worsen |
| Normal grief / bereavement | common | Waves of sadness linked to reminders, preserved self-esteem, yearning for deceased; can coexist with MDD if pervasive hopelessness, guilt, suicidality, or anhedonia | Clinical history; assess function, duration, guilt, psychosis, and suicidal intent |
| Substance- or medication-induced depressive symptoms | common | Alcohol, cannabis, sedatives, stimulants, opioids, corticosteroids, isotretinoin, interferon, beta-blockers, or withdrawal states temporally linked to mood change | Medication/substance timeline, urine toxicology if unclear, reassess after reduction/withdrawal when safe |
| Hypothyroidism / endocrine or metabolic disorder | less common | Fatigue, weight gain, constipation, cold intolerance, menstrual change, bradycardia, dry skin; also consider anaemia, B12 deficiency, diabetes, CKD, malignancy | TSH, CBC/ferritin, B12, electrolytes/creatinine, glucose/A1c as clinically indicated |
| PTSD / trauma-related disorder | less common | Low mood with intrusive memories, avoidance, hyperarousal, dissociation, guilt, irritability, sleep disturbance after trauma | Trauma history + validated PTSD screen; avoid forcing detailed disclosure in first assessment |
| Persistent depressive disorder | less common | Chronic low mood most days for at least 2 years with lower-grade symptoms and intermittent major depressive episodes | Longitudinal history and functional baseline |
Red Flags & Key History
Symptoms
Active suicidal intent, plan, preparatory acts, access to firearms/medications, or recent attempt
Psychotic symptoms, command hallucinations, nihilistic delusions, severe guilt, or catatonic features
Past mania/hypomania or antidepressant-induced agitation/euphoria — suggests bipolar disorder
Perinatal depression with intrusive thoughts of harm, psychosis, or inability to care for infant
Severe self-neglect, dehydration, refusal of food/fluids, or inability to meet basic needs
Anhedonia, early morning wakening, psychomotor change, guilt, poor concentration
Recent bereavement, job loss, relationship breakdown, financial stress, academic stress
Alcohol or cannabis escalation, sedative use, stimulant crash, or opioid use
Signs
Marked psychomotor retardation, mutism, posturing, or stupor
Agitation, pressured speech, reduced need for sleep, disinhibition — suggests mixed or manic state
Poor hygiene, weight loss, dehydration, neglect of dependants
Thyroid signs, pallor, neurological signs, or signs of chronic disease
Restricted affect, tearfulness, low volume speech, slowed cognition
Approach to Investigation
First-line
Clinical suicide risk assessmentAsk directly about ideation, plan, intent, means, past attempts, substance use, psychosis, impulsivity, protective factors, and supports. Obtain collateral when risk is significant
PHQ-9 and functional assessmentUseful for baseline severity and follow-up; item 9 is a prompt for suicide enquiry but does not replace clinical assessment
Bipolar screenAsk about mania/hypomania before antidepressants. Include family history, decreased need for sleep, increased goal-directed activity, impulsive spending/sex, irritability, and psychosis
Medication, substance, and medical reviewReview alcohol, cannabis, opioids, sedatives, stimulants, corticosteroids, isotretinoin, and recent medication changes
Second-line
Targeted labsCBC/ferritin, TSH, B12, electrolytes/creatinine, glucose/A1c, pregnancy test, and other tests guided by symptoms
GAD-7, PTSD screen, alcohol/drug screenUse when comorbidity may change management or risk
Collateral historyImportant for suspected bipolar disorder, psychosis, cognitive impairment, safety concerns, or concealed substance use
Specialist
Urgent psychiatry / crisis team assessmentFor high suicide risk, psychosis, mania, catatonia, severe self-neglect, diagnostic uncertainty with safety concerns, or failure of initial treatment
ECT assessmentFor life-threatening depression, psychotic depression, catatonia, severe suicidality requiring rapid response, or treatment-resistant severe depression
Management Principles
CANMAT 2023 Major Depressive Disorder Guideline + CAMH Suicide Risk Guidance + DSM-5-TR1
Immediate safety and disposition
- If active intent, plan, means, psychosis, intoxication, severe agitation, or inability to maintain safety: do not leave patient alone; remove means; involve crisis psychiatry/ED; consider involuntary assessment under provincial mental health legislation
- Develop a collaborative safety plan: warning signs, coping strategies, contacts, crisis lines, ED instructions, and means restriction
- Document risk formulation, protective factors, capacity, collateral, and follow-up plan rather than only writing low/moderate/high risk
2
Mild depression or subthreshold symptoms
- Psychoeducation, sleep regularity, activity scheduling, exercise, social reconnection, problem-solving, and follow-up within 2-4 weeks
- Offer evidence-based psychotherapy where available: CBT, interpersonal therapy, behavioural activation, or mindfulness-based approaches
- Monitor symptoms with PHQ-9 or similar scales and reassess risk at each visit
3
Moderate to severe major depression
- Offer psychotherapy and/or pharmacotherapy depending on severity, patient preference, prior response, comorbidity, cost, and access
- Common first-line antidepressants in Canada include SSRIs (sertraline, escitalopram, fluoxetine) and SNRIs (venlafaxine, duloxetine); discuss onset 2-4 weeks and full trial 6-8 weeks
- Review adverse effects including GI upset, sexual dysfunction, sleep change, activation, hyponatraemia, bleeding risk, and discontinuation symptoms
4
Bipolar or psychotic features
- Do not start antidepressant monotherapy if bipolar depression is suspected
- Urgent psychiatric input for bipolar depression, psychosis, catatonia, severe suicidality, or diagnostic uncertainty
- Psychotic depression generally requires antidepressant + antipsychotic or ECT-level consideration
Complications & Pitfalls
- Missing bipolar depression: Always ask about mania/hypomania before prescribing an SSRI or SNRI.
- False reassurance from a scale: PHQ-9 item 9 is not a suicide risk assessment.
- Premature medical attribution: Fatigue and low mood are common in depression but also in hypothyroidism, anaemia, B12 deficiency, pregnancy, chronic infection, malignancy, and substance use.
- Undertreating severe depression: Psychosis, catatonia, dehydration, severe weight loss, and inability to care for dependants require urgent escalation.
MCCQE1 Exam Tips
- 1For depressed mood, the next best step is often safety assessment and suicide enquiry before choosing medication
- 2Before starting an antidepressant, screen for bipolar disorder; past decreased need for sleep plus risky behaviour changes the management completely
- 3Psychotic depression, catatonia, inability to eat/drink, and active suicidal intent need urgent psychiatric assessment
- 4Normal bereavement is not automatically MDD; look for pervasive anhedonia, worthlessness, suicidal intent, psychosis, or marked functional decline
- 5A PHQ-9 is useful for measurement-based care but does not replace clinical judgement or collateral history
- 6If the stem gives alcohol escalation, cannabis, opioids, sedatives, steroids, isotretinoin, or stimulant crash, consider substance/medication-induced symptoms
practicetest your knowledge on depressed moodApply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — psychiatric and beyond.
open q-bank