Depressive and Bipolar Disorders

Depressive Disorders

Types of Depressive Disorders (as per DSM-5):

• Disruptive mood dysregulation disorder

• Major depressive disorder

• Persistent depressive disorder (dysthymia)

• Premenstrual dysphoric disorder

• Depressive disorder due to another medical condition

Common Features of All Depressive Disorders:

• Sadness, emptiness, or irritable mood.

• Accompanied by somatic and cognitive changes.

• These changes significantly affect the individual’s capacity to function.

Aetiology of Major Depressive Disorder:

• Multifactorial etiology with both genetic and environmental factors playing a role.

• Genetic Factors:

  • First-degree relatives of depressed individuals are about 3 times as likely to develop depression as the general population.

  • However, depression can occur in people without family histories of depression.

  • Some evidence suggests that genetic factors play a lesser role in late-onset depression than in early-onset depression.

• Biological Risk Factors (in the elderly):

  • Neurodegenerative diseases (especially Alzheimer disease and Parkinson disease).

  • Stroke.

  • Seizure disorders.

  • Cancer.

  • Chronic pain.

• Environmental Factors (Life Events and Hassles):

  • Operate as triggers for the development of depression.

  • Examples: death or loss of a loved one, lack or reduced social support, caregiver burden, financial problems, interpersonal difficulties, and conflicts.

Prevalence of Major Depressive Disorder:

• Twelve-month prevalence is approximately 7%, with marked differences by age group.

• The prevalence in 18 to 29-year-old individuals is threefold higher than the prevalence in individuals aged 60 years or older.

• Females experience 1.5 to 3-fold higher rates than males beginning in early adolescence.

• In the US, depression affects nearly 17 million adults, but these numbers are gross underestimates.

Underlying Pathophysiology:

• The underlying pathophysiology has not been clearly defined.

• Current evidence points to a complex interaction between neurotransmitter availability and receptor regulation and sensitivity underlying the affective symptoms.

• Disturbance in central nervous system serotonin (5-HT) activity is considered an important factor.

• Other neurotransmitters implicated include norepinephrine (NE), dopamine (DA), and glutamate.

Clinical Picture (Diagnostic Criteria):

• Feelings of sadness, low mood, and loss of interest in usual activities must mark a change from a person's previous level of functioning.

• These feelings must have persisted for at least two weeks.

• Must also be accompanied by at least five other common symptoms of depression, including:

  • Change in appetite, losing or gaining weight.

  • Sleeping too much or not sleeping well (insomnia).

  • Fatigue and low energy most days.

  • Feeling worthless, guilty, and hopeless.

  • An inability to focus and concentrate that may interfere with daily tasks.

  • Movements that are unusually slow or agitated (noticeable to others).

  • Thinking about death and dying; suicidal ideation or suicide attempts.

• These symptoms must cause the individual clinically significant distress or impairment in social, occupational, or other important areas of functioning.

• The symptoms must not be a result of substance abuse or another medical condition.

• To be diagnosed with major depression, a person must not have had a manic or hypomanic episode.

Differential Diagnosis:

• Must be distinguished from demoralization and grief.

• Other psychiatric disorders (e.g., anxiety disorders) can mimic or obscure the diagnosis.

• Major depression (unipolar disorder) must be distinguished from bipolar disorder.

• In older patients, depression can manifest as dementia of depression (pseudodementia).

• Differentiating chronic depressive disorders from substance use disorders may be difficult.

• General medical disorders (e.g., hypothyroidism, Parkinson disease) must be excluded as a cause of depressive symptoms.

Types of Depression (Detailed):

• Major Depression ("major depressive disorder" or "clinical depression"):

  • Most common and severe type.

  • Symptoms (five or more for 2 weeks or longer) include loss of interest, weight changes, sleep problems, fatigue, feelings of worthlessness, concentration difficulties, and suicidal thoughts.

  • Can present with anxious distress (feeling tense and restless, worry about bad things, feeling out of control).

  • Can present with melancholy (intense sadness, loss of interest even when good things happen, hopelessness, weight loss, poor sleep with early morning wake-ups, suicidal thoughts).

  • Can present with mixed features (unease, talking a lot, purposeless movement).

• Persistent Depressive Disorder (PDD):

  • Depression that lasts 2 years or longer (previously dysthymia and chronic major depression).

  • Symptoms include changes in appetite and sleep, lack of energy, low self-esteem, trouble concentrating, and feeling hopeless.

• Disruptive Mood Dysregulation Disorder (DMDD):

  • A childhood depressive disorder (age 6 to 18 years).

  • Frequent, intense anger outbursts and ongoing irritability.

  • Causes problems at home and school, and difficulty getting along with peers.

  • Symptoms usually start between ages 6 and 10 and must persist for 12 months or more for diagnosis.

• Seasonal Affective Disorder (SAD):

  • Major depression with a seasonal pattern, often during the winter months.

  • Thought to be caused by problems with serotonin and melatonin levels due to less sunlight.

• Psychotic Depression:

  • Symptoms of major depression along with psychotic symptoms such as hallucinations, delusions, and paranoia.

• Prenatal Depression:

  • Depression that happens during pregnancy.

  • Symptoms include loss of appetite, loss of interest, irritability, sadness, hopelessness, and anxiety.

• Postpartum Depression (PPD):

  • Peripartum or postnatal depression, more severe than baby blues.

  • Intense feelings of sadness, hopelessness, or anxiety lasting longer than 2 weeks after giving birth, affecting bonding and daily life.

• Premenstrual Dysphoric Disorder (PMDD):

  • Depression and other symptoms in the week or two before the start of their period, more severe than PMS.

  • Symptoms include mood swings, irritability, severe anxiety, trouble concentrating, fatigue, and changes in appetite or sleep.

• 'Situational' Depression ('stress response syndrome'):

  • Depressed mood when having trouble managing a stressful life event (e.g., death, divorce, job loss).

• Atypical Depression:

  • A "specifier" describing a pattern of depressive symptoms, different from persistent sadness.

  • Clinical Picture

    • Persistent sadness, hopelessness.

    • Loss of interest or pleasure (anhedonia).

    • Significant changes in weight or appetite.

    • Insomnia or hypersomnia.

    • Fatigue, low energy.

    • Feelings of worthlessness or excessive guilt.

    • Difficulty concentrating, indecisiveness.

    • Recurrent thoughts of death, suicidal ideation.

    • Psychomotor agitation or retardation (slowing of thought/movement).

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    DSM-5 Diagnostic Criteria

    • Five (or more) symptoms present during the same 2-week period and represent a change from previous functioning; at least one symptom must be either (1) depressed mood or (2) loss of interest/pleasure.

      Symptoms include:

      1. Depressed mood most of the day, nearly every day.

      2. Markedly diminished interest or pleasure in activities.

      3. Significant weight loss or gain, or appetite changes.

      4. Insomnia or hypersomnia.

      5. Psychomotor agitation or retardation.

      6. Fatigue or loss of energy.

      7. Feelings of worthlessness or excessive guilt.

      8. Diminished ability to think or concentrate.

      9. Recurrent thoughts of death, suicidal ideation, suicide attempt.

    • Symptoms cause clinically significant distress or impairment.

    • Not attributable to substances or another medical condition.

    • Not better explained by other disorders like Schizoaffective disorder.

    • No manic or hypomanic episodes (unless substance-induced).

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    Etiology (Causes)

    1. Biological Factors:

       • Neurochemical imbalance (serotonin, norepinephrine, dopamine).

       • Genetic predisposition (family history).

       • Hormonal factors (e.g., HPA axis dysregulation).

       • Brain structure changes (hippocampus shrinkage, prefrontal cortex dysfunction).

    2. Psychological Factors:

       • Cognitive distortions (Beck’s cognitive triad: negative view of self, world, future).

       • Learned helplessness (Seligman’s theory).

    3. Social Factors:

       • Stressful life events (loss, trauma).

       • Lack of social support.

       • Chronic illness or disability.

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    Bipolar Disorder

    Types (According to DSM-5)

    1. Bipolar I Disorder:

       • At least one manic episode (may be preceded or followed by hypomanic or depressive episodes).

    2. Bipolar II Disorder:

       • At least one hypomanic episode and one major depressive episode, no full manic episode.

    3. Cyclothymic Disorder:

       • For at least 2 years, periods with hypomanic symptoms and periods with depressive symptoms, but criteria not fully met for a hypomanic or major depressive episode.

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    Clinical Picture

    • Mania:

      • Abnormally elevated, expansive, or irritable mood.

      • Inflated self-esteem or grandiosity.

      • Decreased need for sleep.

      • More talkative (pressured speech).

      • Flight of ideas, racing thoughts.

      • Distractibility.

      • Increased goal-directed activities or psychomotor agitation.

      • Risky behavior (spending sprees, sexual indiscretions).

    • Hypomania:

      • Similar to mania but less severe, no significant functional impairment.

    • Depression (in Bipolar):

      • Symptoms similar to Major Depressive Disorder.

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    DSM-5 Diagnostic Criteria

    Manic Episode:

    • A distinct period of abnormally elevated, expansive, or irritable mood and increased activity/energy lasting at least 1 week, present most of the day, nearly every day.

    • During this period, three (or more) of the following (four if mood is irritable):

      1. Inflated self-esteem/grandiosity.

      2. Decreased need for sleep.

      3. More talkative than usual.

      4. Flight of ideas or racing thoughts.

      5. Distractibility.

      6. Increase in goal-directed activity or psychomotor agitation.

      7. Excessive involvement in risky activities.

    • Causes marked impairment, may necessitate hospitalization, or there are psychotic features.

    Hypomanic Episode:

    • Same symptoms as mania but:

      • Duration of at least 4 consecutive days.

      • Not severe enough to cause marked impairment or hospitalization.

      • No psychotic features.

    Major Depressive Episode:

    • Same as in Major Depressive Disorder (see above).

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    Etiology (Causes)

    1. Biological Factors:

       • Strong genetic component (high heritability; about 60-85%).

       • Neurochemical dysregulation (dopamine, serotonin, norepinephrine).

       • Brain abnormalities (amygdala hyperactivity, prefrontal cortex hypoactivity).

       • Circadian rhythm disturbances (sleep-wake cycle abnormalities).

    2. Psychological Factors:

       • Stressful life events as triggers (e.g., trauma, loss).

       • Cognitive patterns (e.g., goal dysregulation theory: excessive goal pursuit).

    3. Social Factors:

       • Family conflict, poor social support.

       • Life disruptions (moving, job loss).

Bipolar and Related Disorders

• Individuals with bipolar disorder (also called "manic depression") have mood episodes that range from extremes of high energy with an "up" mood to low "depressive" periods.

• During the low phase, individuals experience the symptoms of major depression.

• Traditional antidepressants are not always recommended as standard treatments for bipolar depression and may increase the risk of a "high" phase.

• DSM-5 criteria for mania and hypomania now include changes in activity and energy as well as mood changes.