Mood Disorders

Overview of Mood Disorders

  • Previously referred to as "affective disorders" and "depressive neuroses".

  • All mood disorders involve gross deviations in mood.

  • Despite differences in presentation, mood disorders are fundamentally similar in both children and adults.

  • The prevalence of depression appears to be similar across various subcultures.

Building Blocks for Mood Disorders

  • Three main "building blocks" define the variations in mood disorders:

    • Major Depressive Episode (MDE)

    • Manic Episode

    • Hypomanic Episode

    • Mixed Episode

  • The specific combination of these building blocks determines the specific diagnosis a patient receives.

Definitions of Mood Disorder Episodes

Major Depressive Episode (MDE)

  • Duration: A period of 2 or more weeks.

  • Core symptoms:

    • Either depressed mood or a marked loss of interest or pleasure in nearly all activities.

    • Must have at least four additional symptoms, which may include:

    • Significant weight loss when not dieting or weight gain, or decrease/increase in appetite

    • Insomnia or hypersomnia

    • Psychomotor agitation or retardation

    • Fatigue or loss of energy

    • Feelings of worthlessness or excessive guilt

    • Diminished ability to think or concentrate

    • Recurrent thoughts of death or suicide.

Manic Episode

  • Duration: A period of 1 or more weeks.

  • Core symptoms:

    • Abnormally and persistently elevated, expansive, or irritable mood.

    • Increased goal-directed activity or energy.

    • Must include at least three other symptoms, such as:

    • Inflated self-esteem or grandiosity

    • Decreased need for sleep

    • More talkative than usual or pressure to keep talking

    • Flight of ideas or feeling that thoughts are racing

    • Easily distracted

    • Increased goal-directed activities (either socially, at work or school, or sexual) or psychomotor agitation.

Hypomanic Episode

  • Definition: Characterized by similar symptoms to mania but of lesser intensity and duration.

  • Duration: Must last at least 4 consecutive days.

  • Difficulties in identification compared to mania due to less severe symptoms.

Mixed Episode

  • Definition: Features of both depression and mania occurring simultaneously.

Introduction to Mood Disorders in DSM-5

  • Mood disorders classified in two main chapters:

    • Depressive Disorders

    • Bipolar Disorders

Depressive Disorders

  • Includes:

    • Major Depressive Disorder (MDD)

    • Persistent Depressive Disorder

    • Premenstrual Dysphoric Disorder

    • Disruptive Mood Dysregulation Disorder

Major Depressive Disorder (MDD)

Overview and Defining Features

  • Features include a major depressive episode as the core symptom.

Facts and Statistics

  • Lifetime prevalence:

    • Women: 10%-20%

    • Men: 5%-12%

  • Onset: Usually in the late 20s to early 30s.

  • Variable course; single MDE relatively rare.

    • If an individual has had one MDE, the 50%-60% chance of having another follows.

    • If they have experienced two MDEs, the chance of a third rises to about 90%.

Associated Features

  • Highly comorbid with:

    • Anxiety disorders

    • Alcohol dependence

  • Increased risk of developing a manic episode and higher suicide rates.

  • Severe psychological stressors often precipitate episodes of MDD.

Persistent Depressive Disorder

Overview and Defining Features

  • Characterized by persistently depressed mood lasting at least 2 years (1 year for children/adolescents).

  • Symptoms can be unchanged over long periods (up to 20 years or more).

Course Specifiers

  • Types of persistent depressive disorder include:

    • Pure dysthymic syndrome (no full criteria for MDE in last 2 years)

    • Persistent major depressive episode

    • Intermittent major depressive episode with a current episode (current MDE with at least 8 consecutive weeks without one in the last 2 years)

    • Intermittent major depressive episode without a current episode (no current MDE, but one or more MDEs in the last 2 years).

Premenstrual Dysphoric Disorder

Overview and Defining Features

  • Requires at least 5 symptoms present the week prior to menses and significantly diminish shortly after. Symptoms may include:

    • Affective lability

    • Irritability/anger

    • Depressed mood/hopelessness

    • Anxiety/tension

    • Decreased interest in activities

    • Poor concentration

    • Low energy

    • Changes in appetite/sleep

    • Sensations of being overwhelmed

    • Physical symptoms (e.g., breast tenderness, bloating).

Controversy

  • Questions regarding whether this disorder pathologizes severe cases of premenstrual syndrome and reinforces stereotypes regarding women and "raging hormones".

BIPOLAR DISORDERS

  • Includes:

    • Bipolar I Disorder

    • Bipolar II Disorder

    • Cyclothymic Disorder

Bipolar I Disorder

Overview and Defining Features

  • Must include at least one manic episode in the clinical presentation.

Facts and Statistics

  • Lifetime prevalence: 0.4% to 1.6%.

  • Does not significantly differ by sex.

  • Onset usually occurs in late teens or early adulthood.

  • High chance of recurrence after the first manic episode

    • 90% of individuals who experience one manic episode will have future episodes.

  • Rapid cycling: Defined as having four or more episodes in one year, present in a minority of cases.

Associated Features

  • High comorbidity with anxiety and substance use disorders.

  • Increased suicide risk; suicidal ideation and attempts more common in MDE or mixed episodes.

Bipolar II Disorder

Overview and Defining Features

  • Involves one or more MDEs alongside one or more hypomanic episodes.

Cyclothymic Disorder

Overview and Defining Features

  • A chronic form of bipolar disorder that involves hypomanic episodes and depressive symptoms persisting for at least 2 years (1 year for children/adolescents).

Specifiers for Mood Disorders

  • Used to describe the symptoms and course of mood disorders.

  • Types of specifiers include:

    • Mixed features (3 or more manic/hypomanic symptoms during an MDE)

    • Anxious distress (2 or more anxiety symptoms during an MDE)

    • Atypical (oversleep, overeat, gain weight, anxious)

    • Melancholic (loss of pleasure/interest, almost all activities)

    • Catatonic (psychomotor disturbance such as mutism, waxy flexibility)

    • Psychotic (mood congruent/incongruent hallucinations/delusions).

Bereavement

  • Bereavement defined as the objective state of having lost a loved one.

  • Symptoms can mirror those of depression; cultural context significantly influences the expression of grief.

  • A mood disorder is not diagnosed unless certain criteria are met.

Causal Factors for Mood Disorders

Biological Causal Factors

  1. Familial and Genetic Influences:

    • Family and adoption studies indicate familial clustering of mood disorders.

  2. Twin Studies:

    • High concordance rates in identical twins for mood disorders (approximately 60% for bipolar disorders).

    • Higher heritability rates in females (40%) compared to males (21%).

    • Unipolar and bipolar disorder vulnerabilities appear to be inherited separately.

  3. Neurobiological Influences:

    • Lower levels of monoamines (serotonin, norepinephrine, dopamine) link to mood disorders.

    • Low serotonin may cause dysregulation in other neurotransmitters.

    • Abnormalities in serotonin and norepinephrine receptors can be found in mood disorders.

  4. Endocrine System:

    • Regulation of hormones is crucial; the Hypothalamic-Pituitary-Adrenal (HPA) axis is often overactive in depression, causing increased levels of stress hormones (such as cortisol), which may inhibit monoamine receptors.

  5. Sleep and Circadian Rhythms:

    • Disruption in sleep patterns affects mood and depressive symptoms.

Psychological Causal Factors

  1. Stress:

    • 50%-80% of individuals experiencing severe stress develop depression.

    • Understanding the nature and timing of stress events is crucial as it can influence treatment outcomes.

  2. Learned Helplessness:

    • Individuals perceive a lack of control over stressful situations, leading to depression.

    • Depressive attributional style:

      • Internal

      • Stable

      • Global

    • This style fosters a sense of hopelessness.

  3. Cognitions:

    • Beck’s cognitive theory posits that depression results from negative event interpretations.

    • Depressed individuals often exhibit cognitive errors, including:

      • Arbitrary inference

      • Overgeneralization

    • Depressive cognitive triad:

      • Negative thoughts about self

      • Negative thoughts about the world

      • Negative thoughts about the future

Social and Cultural Causal Factors

  1. Marriage:

    • Relationship status influences mood disorders.

  2. Sex and Gender:

    • Prevalence of unipolar mood disorders often varies by sex; potential influencing factors vary.

  3. Social Support:

    • The level of perceived social support is directly related to depression.

    • Lack of support predicts late-onset depression; high support can facilitate better recovery from major depressive episodes.

Treatments for Mood Disorders

  • Treatments can be biological, cognitive, behavioral, or interpersonal in nature.

1. Medications

  • Tricyclic Antidepressants:

    • Primarily used for depression (e.g., Tofranil, Elavil).

    • Functions by blocking the reuptake of norepinephrine and other neurotransmitters but carry negative side effects and may be lethal in large doses.

  • MAO Inhibitors:

    • Agitate serotonin and norepinephrine breakdown by blocking monoamine oxidase; effectiveness is higher than tricyclics but necessitate diet restrictions (avoidance of tyramine-rich foods such as beer, red wine, cheese).

  • SSRIs:

    • Selective serotonin reuptake inhibitors (e.g., Fluoxetine or Prozac) are effective, posing no unique risk for violence or suicide but still have common side effects.

  • Lithium:

    • A mood stabilizer used primarily for bipolar disorders; effective for preventing manic episodes, though mechanisms remain unclear, similar to common side effects.

2. Electroconvulsive Therapy (ECT)

  • A biomedical technique for severe depression consisting of sending electrical currents through the brain of an anesthetized patient, resulting in temporary seizures.

  • Generally requires 6 to 10 sessions; effective against severe depression with few side effects, although memory loss can occur.

3. Psychotherapy

  • Cognitive Therapy:

    • Aims to rectify cognitive errors alongside behavioral components to improve mood.

  • Behavioral Activation:

    • Encourages engagement in rewarding activities, while decreasing unproductive behaviors.

  • Interpersonal Psychotherapy:

    • Focuses on managing problematic interpersonal relationships effectively.

4. Phototherapy

  • Specifically for Seasonal Affective Disorder (SAD) and requires exposure to bright light (2500 lux) for approximately two hours daily, best attempted in morning hours.

Summary of Mood Disorders

  • Mood disorders reflect significant deviations in mood, diagnosed based on the combination of mood episodes (the "building blocks").

  • Etiology includes a multi-faceted interplay between genetics, neurobiology, environmental factors, and interpersonal relationships, guiding treatment strategies in biological, cognitive, behavioral, and interpersonal domains.