Depressive Disorders

Understanding Depression vs. Sadness

  • Sadness is a normal emotional state; depression is a clinical condition marked by prolonged and severe symptoms.

  • Key difference: duration, intensity, and impact on functioning.

Study Pointer:
Understand the continuum from normal sadness to clinical depression, especially how impairment in daily life distinguishes them.

Types of Depressive Disorders (DSM-5)

  1. Major Depressive Disorder (MDD)

  2. Persistent Depressive Disorder (Dysthymia)

  3. Disruptive Mood Dysregulation Disorder (DMDD)

  4. Premenstrual Dysphoric Disorder (PMDD)

  5. Substance/Medication-Induced Depressive Disorder

  6. Depressive Disorder Due to Another Medical Condition

  7. Other Specified/Unspecified Depressive Disorders

Study Pointer:
Be able to define and differentiate each disorder, particularly by onset, duration, and severity.

Major Depressive Disorder (MDD)

  • Criteria: Depressive episode lasting ≥2 weeks; no history of mania or hypomania.

  • Symptoms: Anhedonia, fatigue, changes in sleep/appetite, suicidal thoughts, psychomotor changes.

  • Recurrent MDD: Two+ episodes separated by ≥2 months of remission.

  • Associated Features: Anxiety, obsessive rumination, physical pain, and high suicide risk.

Study Pointer:
Know the 9 DSM-5 criteria and remember the "SIGECAPS" acronym: Sleep, Interest, Guilt, Energy, Concentration, Appetite, Psychomotor, Suicidal ideation.

Persistent Depressive Disorder (Dysthymia)

  • Chronic low mood lasting ≥2 years (1 year in children), not symptom-free >2 months.

  • Less severe but more persistent than MDD.

  • May co-occur with MDD: "double depression."

Study Pointer:
Distinguish from MDD by duration and intensity. Note high risk of comorbid Cluster B & C personality disorders.

Disruptive Mood Dysregulation Disorder (DMDD)

  • Onset: Before age 10; diagnosis between 6-18.

  • Symptoms: Severe temper outbursts, chronic irritability, present in multiple settings.

  • Not episodic like bipolar disorder.

Study Pointer:
Differentiate DMDD from ODD, ADHD, and Bipolar Disorder. DMDD is chronic and mood-based.

Premenstrual Dysphoric Disorder (PMDD)

  • Mood symptoms related to menstrual cycle; occur during luteal phase, remit after menses.

  • Requires tracking for 2 consecutive cycles.

  • Common symptoms: irritability, mood swings, fatigue, physical discomfort,

Study Pointer:
Distinguish PMDD from PMS and hormone-induced mood changes. Must track symptoms prospectively.

Specifiers for Depressive Disorders

These clarify symptom patterns and influence treatment:

  • Psychotic features: Hallucinations/delusions

  • Anxious distress: Tension, worry, poor concentration

  • Mixed features: Some manic symptoms during depression

  • Melancholic features: Anhedonia, guilt, early morning waking

  • Catatonic features: Motor immobility or excessive activity

  • Atypical features: Oversleeping, overeating, mood reactivity

  • Peripartum onset: During pregnancy or within 4 weeks postpartum

  • Seasonal pattern (SAD): Related to light exposure (e.g., winter depression)

Study Pointer:
Learn which specifiers apply to MDD vs. PDD. Understand how they guide treatment plans.

Differential Diagnosis

  • Bipolar Disorders: Look for manic/hypomanic episodes.

  • Psychotic Disorders: Schizoaffective includes psychosis outside mood episodes.

  • Adjustment Disorder: Linked to a specific stressor, doesn’t meet MDD criteria.

  • Bereavement: Grief is typically wave-like, not persistent.

  • Medical/Substance Conditions: Rule out hypothyroidism, anemia, medication effects.

Study Pointer:
Use temporal pattern, episode history, and symptom severity to rule out other conditions.

Comorbidities

  • Anxiety Disorders, PTSD, OCD

  • Eating Disorders (Anorexia, Bulimia)

  • Substance Use Disorders

  • Borderline Personality Disorder

Gender Differences:

  • Women: More anxiety and eating disorder comorbidity

  • Men: More substance abuse

Study Pointer:
Understand how comorbid conditions influence diagnosis and prognosis.

Causes of Depression

Biological Factors

  • Genetics: 2-4x risk in children of depressed parents; 37-50% heritability.

  • Brain Features: Reduced prefrontal activity, abnormal cortical-limbic circuits.

  • Neurotransmitters: Low serotonin, dopamine, norepinephrine; high cortisol.

  • Sleep: Disrupted REM, circadian rhythm changes, early waking.

Study Pointer:
Know key brain areas and neurotransmitters involved in depression.

Environmental Factors

  • Stressful Life Events: Divorce, loss, trauma.

  • Cognitive Factors: Negative cognitive triad, learned helplessness, ANTs (automatic negative thoughts).

  • Interpersonal Issues: Marital discord, social withdrawal.

  • Family Dynamics: Depressed parents, insecure attachment, overinvolvement/conflict.

Study Pointer:
Apply the diathesis-stress model: biological vulnerability + environmental trigger = disorder.

Suicide and Depression

  • Suicide is a major risk in depressive disorders, especially among adolescents and elderly.

  • Common precursors: Hopelessness, impulsivity, emotional instability, interpersonal loss.

Suicide Risk Factors

  • Psychological: Low self-esteem, self-doubt, trauma

  • Stressful Events: Exit events (e.g., death, breakup)

  • Genetic: Family history

  • Sociocultural: Male gender, isolation, cultural stigma

  • Copycat (Werther) Effect: Media coverage can influence vulnerable individuals

Study Pointer:
Learn myths vs. facts. For example, talking about suicide does NOT increase risk, and previous attempts are a major warning sign.

Final Study Tips

  • Memorize core symptoms of MDD and PDD.

  • Practice differential diagnosis by comparing symptom patterns.

  • Understand biological and environmental risk factors.

  • Learn specifiers and how they shape treatment.

  • Recognize comorbid disorders and suicide risk factors.