Mood disorder Study Guide

📖 Core Concepts Mood disorder: Persistent disturbance of mood (elevated or depressed) that impairs function. DSM‑5 structure: Two chapters – Depressive and Related Disorders and Bipolar and Related Disorders; each disorder defined by symptom count, duration, and impact. Manic vs. hypomanic episode: Mania – ≥ 1 week, marked impairment; hypomania – ≥ 4 days, no severe functional loss. Major depressive episode: ≥ 5 symptoms (incl. depressed mood or anhedonia) most of the day for ≥ 2 weeks. Substance‑induced vs. primary mood disorder: Direct physiological effect of a drug vs. independent pathology. Lithium’s unique role: Reduces suicide risk and overall mortality in mood‑disordered patients. 📌 Must Remember MDD diagnosis – 5+ symptoms ≥ 2 weeks, must include either depressed mood or loss of interest. Bipolar I – at least one manic episode (depression optional). Bipolar II – recurrent hypomanic + major depressive episodes; no full mania. Cyclothymic disorder – chronic hypomanic‑plus‑dysthymic symptoms, never meeting full criteria. Atypical depression – mood reactivity + weight gain/hypersomnia + rejection sensitivity. Melancholic depression – lack of mood reactivity, early‑morning awakening, psychomotor retardation, weight loss. Psychotic depression – major depression + mood‑congruent delusions/hallucinations. Seasonal Affective Disorder (SAD) – ≥ 2 winter episodes, none in other seasons, over 2 years. Risk factors – high neuroticism, family history, female sex (≈2× risk), genetics (76 % concordance in MZ twins). Lithium – only mood stabilizer proven to lower suicide rates. 🔄 Key Processes Diagnosing a Major Depressive Episode Count symptoms (≥ 5). Verify duration (≥ 2 weeks). Ensure symptoms present most of the day and cause functional impairment. Confirm either depressed mood or anhedonia is present. Diagnosing a Manic Episode Confirm ≥ 1 week of abnormally elevated/irritable mood. Identify ≥ 3 (or 4 if irritability only) characteristic symptoms (e.g., inflated self‑esteem, decreased need for sleep, pressured speech). Check for marked impairment or hospitalization. Bipolar I vs. Bipolar II Decision Tree Mania present? → Bipolar I. Only hypomania + major depression? → Bipolar II. Treatment Selection for Depression Start antidepressant (SSRI first‑line). Add CBT if moderate‑severe or partial response. Consider Lithium or antipsychotic if psychotic features present. Lithium Taper for Suicide Prevention Maintain therapeutic serum level (0.6–1.2 mEq/L). Monitor renal, thyroid, and ECG parameters regularly. 🔍 Key Comparisons Atypical vs. Melancholic Depression Atypical: mood reactivity yes, weight gain, hypersomnia, rejection sensitivity. Melancholic: mood reactivity no, early‑morning awakening, weight loss, psychomotor retardation. Mania vs. Hypomania Mania: ≥ 1 week, severe functional impairment, may need hospitalization. Hypomania: ≥ 4 days, no marked impairment, often missed. Substance‑induced vs. Primary Mood Disorder Substance‑induced: onset closely follows substance use/withdrawal; resolves with abstinence. Primary: persists despite substance cessation, independent course. Lithium vs. Other Mood Stabilizers Lithium: suicide‑protective, requires serum monitoring. Valproate/Carbamazepine: effective for mania but no proven suicide benefit. ⚠️ Common Misunderstandings “Depression always follows mania” – Bipolar I can present with mania without prior depression. “All hypomanic episodes need hospitalization” – By definition, hypomania does not cause marked impairment. “Antidepressants cure depression” – They alleviate symptoms; relapse risk remains without psychotherapy or maintenance. “Benzodiazepines are safe long‑term” – Chronic use can induce or worsen depression and cause protracted withdrawal mimicking psychosis. 🧠 Mental Models / Intuition “Mood Spectrum”: Imagine a line from deep depression → euthymia → hypomania → mania. Most patients swing somewhere along this line; bipolar = movement across both sides, unipolar = stays on the depressive side. “5‑symptom rule”: Think of a “symptom checklist” as a lock; you need at least 5 matching teeth (including mood or anhedonia) to open the MDD diagnosis. 🚩 Exceptions & Edge Cases Bereavement exclusion – Removed in DSM‑5; grief can meet MDD criteria if symptoms persist > 2 weeks and meet other thresholds. Mixed features specifier – Depressive episodes with ≥ 3 manic symptoms qualify for “mixed” specifier, affecting treatment choice (avoid pure antidepressants). BD‑NOS / Unspecified – Used when symptoms are sub‑threshold; still warrant close monitoring and may evolve into a full disorder. 📍 When to Use Which SSRI vs. TCA – Start SSRI for first‑line (better side‑effect profile); reserve TCA for treatment‑resistant cases. Lithium vs. Anticonvulsant – Choose Lithium when suicide risk is high; choose valproate/carbamazepine for rapid‑cycling or contraindication to lithium. Light therapy vs. Antidepressant – Use light therapy as first‑line for SAD; add antidepressant if response inadequate. MDQ screening – Use in any patient with depressive symptoms to rule out underlying bipolarity before prescribing antidepressants alone. 👀 Patterns to Recognize Weight change direction: Weight gain → consider atypical depression; weight loss → melancholic features. Sleep pattern: Hypersomnia → atypical; early‑morning awakening → melancholia. Rejection sensitivity: Strong cue for atypical depression. Seasonal timing: Recurrent winter‑only episodes → SAD. Substance timeline: Mood shift that starts within weeks of heavy alcohol/benzodiazepine use → substance‑induced mood disorder. 🗂️ Exam Traps “Depression must follow a stressful life event” – Not required; many cases are endogenous. “Manic episodes always include psychosis” – Psychotic features are optional; most mania is non‑psychotic. “All bipolar patients have rapid cycling” – Only a subset; rapid cycling is ≥ 4 mood episodes/year. “Lithium is contraindicated in depression” – Actually indicated for bipolar depression and suicide prevention. “Benzodiazepine‑induced depression resolves immediately after stopping the drug” – Withdrawal can last months and mimic depressive symptoms. --- Use this guide for rapid recall right before the exam. Focus on the bolded keywords, contrast points, and decision rules to eliminate distractors quickly.