Mood disorders sit squarely on the NEET PG high-yield list — examiners love DSM-5 vignettes, drug-side-effect crosswords, and the legal framework around involuntary admission. Where psychiatry once felt soft and subjective, the DSM-5 era has tightened criteria into testable timelines, symptom counts, and exclusion clauses that translate directly into single-best-answer stems.
This NEETPGAI deep dive walks through the DSM-5 criteria for major depressive disorder, bipolar I and II, persistent depressive disorder, postpartum mood states, and the management ladders examiners ask about — antidepressant selection, mood stabilizer monitoring, ECT indications, and the suicide-risk assessment frameworks that turn up in clinical-vignette form. Pair this with the Psychiatry hub and the schizophrenia and psychotic disorders guide for full mental-health fluency.
Major depressive disorder — the DSM-5 spine
MDD requires five or more symptoms during the same 2-week period, with at least one being depressed mood or loss of interest or pleasure (anhedonia). Use the SIG E CAPS mnemonic for the supporting symptoms:
Sleep — insomnia or hypersomnia
Interest loss — anhedonia
Guilt — feelings of worthlessness, inappropriate guilt
Appetite change — weight loss or gain >5% in a month
Psychomotor agitation or retardation
Suicidality — recurrent thoughts of death, ideation, plan, or attempt
Symptoms must cause clinically significant distress or functional impairment, not be attributable to a substance or another medical condition, and not be better explained by schizoaffective or related psychotic disorder.
Specifiers that change management
Specifier
Clinical clue
Treatment shift
Anxious distress
Tense, restless, fear of loss of control
SSRI + cognitive therapy
Mixed features
At least 3 manic/hypomanic symptoms during depressive episode
Symptoms during pregnancy or within 4 weeks postpartum
Sertraline preferred; rule out postpartum psychosis
Seasonal pattern
Recurrence linked to seasons (typically winter)
Bright light therapy 10,000 lux; bupropion XL
Persistent depressive disorder (dysthymia)
A chronic low-grade depressed mood for 2 or more years (1 year in children/adolescents) with at least 2 of: poor appetite, insomnia/hypersomnia, low energy, low self-esteem, poor concentration, hopelessness. Symptoms cannot be absent for more than 2 months. Patients can have superimposed major depressive episodes — termed "double depression," a classic NEET PG vignette.
Bipolar spectrum — mania vs hypomania
The single most testable distinction in mood-disorder MCQs is the line between mania and hypomania.
Feature
Manic episode (Bipolar I)
Hypomanic episode (Bipolar II)
Duration
At least 7 days (or any duration if hospitalised)
At least 4 consecutive days
Severity
Marked impairment, may need hospitalisation, may have psychosis
No marked impairment, no psychosis, no hospitalisation
Functional effect
Severe disruption of work, social, relationships
Observable change but functioning often preserved or even enhanced
Diagnosis
Bipolar I (one episode is enough)
Bipolar II (requires both hypomania + MDE)
Both share the DIG FAST symptom set (3 needed if mood is elevated, 4 if mood is only irritable):
Mixed features specifier: at least 3 symptoms of the opposite pole during a current episode. Higher suicide risk; valproate or atypical antipsychotic preferred over lithium.
Rapid cycling: 4 or more mood episodes in 12 months. Worse prognosis. Valproate or lamotrigine preferred. Antidepressants can induce switching.
Cyclothymic disorder
Two years (1 year in adolescents) of fluctuating hypomanic and depressive symptoms not meeting threshold for full episodes. Symptom-free intervals less than 2 months.
Pharmacotherapy of depression — choose by side-effect fit
Common side effects: nausea, sexual dysfunction (50%), insomnia, GI upset, hyponatremia (especially elderly).
Discontinuation syndrome: flu-like symptoms, dizziness, electric-shock sensations on abrupt stop, especially with paroxetine (short half-life).
Serotonin syndrome: triad of mental status change, autonomic instability, neuromuscular hyperactivity (clonus, hyperreflexia). Stop the drug, give cyproheptadine.
TCAs (amitriptyline, imipramine, nortriptyline, clomipramine) — effective but cardiotoxic in overdose (QRS widening, arrhythmia). Anticholinergic, antihistaminic, alpha-blockade side effects. MAOIs (phenelzine, tranylcypromine, selegiline) — tyramine-rich food causes hypertensive crisis; 2-week washout from SSRI before switching.
Mood stabilizers — bipolar cornerstones
Lithium
Gold standard for classic mania and maintenance. Reduces suicide risk independently — a uniquely valuable property.
Therapeutic range: 0.6-1.2 mEq/L (acute mania up to 1.5).
Toxicity: >1.5 mEq/L. Tremor, ataxia, dysarthria, confusion, seizures, coma. Hemodialysis if >2.5 or symptomatic.
Side effects: fine tremor, polyuria/polydipsia (nephrogenic DI), hypothyroidism, weight gain, acne, T-wave flattening, leukocytosis, Ebstein anomaly in pregnancy.
Monitoring: TSH, creatinine, electrolytes, lithium level every 6 months once stable.
Valproate
First-line for mixed features, rapid cycling, and dysphoric mania.
Therapeutic range: 50-125 mcg/mL.
Side effects: weight gain, alopecia, tremor, thrombocytopenia, hepatotoxicity, hyperammonemia, pancreatitis.
Pregnancy: contraindicated — high neural tube defect risk and intellectual impairment in offspring.
Lamotrigine
First-line for bipolar depression maintenance. Slow titration mandatory (Stevens-Johnson syndrome risk if dose escalated rapidly). Less effective for acute mania.
Atypical antipsychotics
Olanzapine, quetiapine, risperidone, aripiprazole, lurasidone, cariprazine — all FDA-approved for various phases. Quetiapine and lurasidone are the only monotherapies approved for bipolar depression. Olanzapine + fluoxetine combination (Symbyax) approved for bipolar depression.
Critical NEET PG rule
Never give antidepressant monotherapy in bipolar disorder. It risks switching to mania or rapid cycling. Always cover with a mood stabilizer or atypical antipsychotic first.
Electroconvulsive therapy — when and why
ECT remains the most effective treatment for severe depression, with response rates 70-90%.
Absolute and relative indications
Severe MDD with active suicidality
Depression with psychotic features
Catatonic depression or catatonia of any cause
Treatment-resistant depression (failure of 2+ adequate antidepressant trials)
Severe mania unresponsive to medication
Postpartum psychosis (fast, safe, allows continued breastfeeding)
Pregnancy when medications are unsafe
Patients refusing food/fluids ("danger to self by neglect")
Neuroleptic malignant syndrome refractory to bromocriptine
Practical pearls
Stimulus dosing: unilateral right-sided causes less cognitive impairment; bilateral has faster response.
Pre-ECT workup: ECG, electrolytes, anaesthesia review. Pregnancy is NOT a contraindication.
Suicide risk assessment
Previous attempt is the single strongest predictor of completed suicide. Other risk factors: male sex, advancing age, alcohol/substance use, hopelessness, social isolation, recent loss, access to lethal means, family history, chronic illness, command hallucinations.
Practical scales
SAD PERSONS scale — 10-item screening (Sex, Age, Depression, Previous attempt, Ethanol, Rational thinking loss, Social support lacking, Organised plan, No spouse, Sickness).
Columbia Suicide Severity Rating Scale (C-SSRS) — gold standard in clinical research and emergency settings.
For NEET PG, examiners often ask: "What is the strongest single predictor of suicide?" — answer is previous suicide attempt, especially within the last year.
Postpartum mood states
Condition
Onset
Duration
Severity
Treatment
Postpartum blues
2-5 days postpartum
Self-limited <2 weeks
Mild, tearful, mood lability
Reassurance, support
Postpartum depression
Within 4 weeks (DSM); up to 12 months clinically
Weeks to months
Full MDE with infant focus
Sertraline, CBT, brexanolone (SAGE-547)
Postpartum psychosis
First 2 weeks postpartum
Acute, dramatic
Hallucinations, delusions, infanticidal ideation
Hospitalisation, mood stabilizer + antipsychotic, often ECT
Postpartum psychosis is a psychiatric emergency. Risk of infanticide and suicide is dramatically elevated. Strong association with bipolar disorder.
High-yield NEET PG MCQ traps
Bereavement vs MDD — DSM-5 removed the bereavement exclusion; MDD can be diagnosed during grief if criteria are met.
Antidepressant-induced mania — first manic episode triggered by SSRI in a previously depressed patient often unmasks bipolar disorder.
Serotonin syndrome vs NMS — both have hyperthermia and altered mental status. Serotonin syndrome has clonus and hyperreflexia; NMS has lead-pipe rigidity and hyporeflexia.
Psychotic depression — never use antidepressant alone; combine with antipsychotic OR use ECT.
Mental Healthcare Act 2017 — the legal layer
The Mental Healthcare Act 2017 replaced the Mental Health Act 1987 and reframed Indian mental health law around dignity, autonomy, and right-to-care. NEET PG and FMGE both ask conceptual questions on the Act.
Decriminalisation of suicide: Section 115 — anyone attempting suicide is presumed to have severe stress and shall not be prosecuted under Section 309 IPC (now BNS 2023 equivalent). Government must provide care and rehabilitation.
Advance directive: Patients can specify in writing how they wish to be treated when unable to consent.
Nominated representative: every patient appoints one; replaces "guardian" concept.
Independent admission: voluntary, patient-driven, can self-discharge.
Supported admission: requires nominated representative consent + medical-officer certification. Reviewed by Mental Health Review Board if >30 days.
Mental Health Review Boards: state-level quasi-judicial bodies with appellate function.
Right to community living, dignity, confidentiality, equality, free legal aid.
Insurance parity: every insurer must provide medical insurance for mental illness on same basis as physical illness.
Recent updates and Indian context
Esketamine (Spravato) — intranasal NMDA antagonist approved for treatment-resistant depression. Rapid onset within hours. Requires REMS-supervised administration in India.
Brexanolone and zuranolone — neuroactive steroid GABA-A modulators approved for postpartum depression.
Psilocybin trials — Phase 3 trials in treatment-resistant depression; not yet approved in India.
District Mental Health Programme (DMHP) — operational under National Mental Health Programme; integrates mental health into primary care across all districts.
Tele-MANAS: national tele-mental-health helpline (14416) launched 2022 — important for PSM/community medicine cross-questions.
Frequently asked questions
What are the DSM-5 criteria for major depressive disorder?
MDD requires five or more symptoms during the same 2-week period including either depressed mood or anhedonia, plus weight or appetite change, sleep disturbance, psychomotor changes, fatigue, worthlessness or guilt, decreased concentration, and recurrent thoughts of death. Symptoms must cause significant impairment and not be due to substance or medical condition.
How do you differentiate bipolar I from bipolar II?
Bipolar I requires at least one full manic episode lasting 7 days or any duration if hospitalisation is needed, with marked impairment or psychosis possible. Bipolar II requires at least one hypomanic episode (4 or more days, less severe, no hospitalisation) plus at least one major depressive episode. Mania automatically rules out bipolar II.
Which antidepressant is safest in pregnancy and lactation?
Sertraline is generally considered the SSRI of choice in pregnancy and breastfeeding due to lowest serum levels in breastmilk and reassuring safety data. Paroxetine is avoided due to first-trimester cardiac defect risk. Always discuss risk-benefit of untreated maternal depression versus medication exposure with the patient.
What are the absolute indications for ECT in mood disorders?
Severe MDD with acute suicidality, depression with psychotic features, catatonic depression, treatment-resistant depression after multiple failed trials, severe mania, postpartum psychosis, and patients who refuse food or fluids. ECT is also first-line when rapid response is essential or pharmacotherapy is contraindicated such as in pregnancy.
What does the Mental Healthcare Act 2017 say about admission?
The Act mandates dignity-based care, decriminalises suicide attempts, and creates supported admission categories. Independent admission is voluntary; supported admission requires nominated representative consent and medical board review beyond 30 days. Advance directives and right to community living are guaranteed. The Act replaced the Mental Health Act 1987.
This content is for educational purposes for NEET PG exam preparation. It is not a substitute for professional medical advice, diagnosis, or treatment. Clinical information has been reviewed by qualified medical professionals.
Written by: NEETPGAI Editorial Team
Reviewed by: Pending SME Review
Last reviewed: April 2026
