M05.09.11 M05.09.03 Mood disorders

Mood disorders are a class of mental illnesses characterized by persistent disturbances in a person’s emotional state, which can significantly affect their thoughts, behavior, and overall well-being. This section provides an overview of some common mood disorders encountered in clinical practice. Understanding these conditions is crucial for medical students.

Major Depressive Disorder (MDD)

• Epidemiology: Women are more likely to experience MDD than men.
• Diagnostic Criteria (DSM-5):
  • Presence of depressed mood or anhedonia (loss of pleasure) for at least two weeks, along with other symptoms such as:
    • Low energy or fatigue
    • Difficulty concentrating or making decisions
    • Sleep disturbances (insomnia or hypersomnia)
    • Changes in appetite or weight (weight loss or gain)
    • Psychomotor agitation or retardation
    • Feelings of worthlessness or guilt
    • Recurrent thoughts of death or suicidal ideation
  • Symptoms must cause significant impairment in social, occupational, or other important areas of functioning.
• Biological Considerations: MDD is associated with decreased levels of neurotransmitters like norepinephrine, dopamine, and serotonin in the brain.
• Suicide Risk: Individuals with MDD have a 15% lifetime risk of suicide.

Treatment:
* Antidepressant medications are the mainstay of treatment for MDD. * Psychotherapy, particularly cognitive behavioral therapy (CBT), can also be beneficial.

Seasonal Affective Disorder (SAD):

• Description: A subtype of MDD characterized by recurrent depressive episodes occurring primarily during winter months in the Northern Hemisphere.
• Symptoms: Similar to MDD, but may also include social withdrawal, craving for carbohydrates, and hypersomnia.
• Cause:
  • Disruption in melatonin production due to decreased sunlight exposure.
• Treatment: Bright light therapy (phototherapy) is a highly effective treatment for SAD.

Persistent Depressive Disorder (PDD):

• Comparison to MDD: A less severe and chronic form of depression compared to MDD.
• Diagnostic Criteria (DSM-5):
  • Depressive symptoms present for at least two years on most days.
  • Symptoms do not meet the criteria for a major depressive episode.
  • Functional impairment is less severe compared to MDD.
• Treatment: Psychotherapy is the primary treatment approach for PDD.

Bipolar Disorder

• Genetics: Highly heritable; considered the most genetic of all psychiatric disorders. Men and women are equally affected.
• Bipolar I Disorder: Characterized by a manic episode (lasting at least one week) or a mixed episode (symptoms of mania and depression occurring simultaneously) that causes significant impairment in functioning.
  • Manic episode symptoms include:
    • Increased energy and activity level
    • Decreased need for sleep
    • Elation or euphoria
    • Inflated sense of self-esteem or grandiosity
    • Racing thoughts and flight of ideas
    • Increased talkativeness and distractibility
    • Increased risk-taking behavior
    • Poor judgment
  • Depressive episodes are also common in bipolar I disorder but are not necessary for diagnosis.
• Bipolar II Disorder: Characterized by hypomanic episodes (less severe than manic episodes) alternating with major depressive episodes.

Table 9-6. Bipolar Disorder Classification

Cyclothymic Disorder:

• Description: Characterized by numerous mood swings over at least two years, with periods of hypomania alternating with periods of mild depression (neither meeting the full criteria for a manic or major depressive episode).

Table 9-7. Mood Disorders Summary

Important Points to Remember

• Mood disorders are common and can significantly impact a person’s life.
• Early diagnosis and treatment are crucial for improving outcomes.
• Treatment options include medications and psychotherapy.