Lesson 10.1: Mood and Anxiety Disorders

Introduction

In this lesson, students, we will explore key concepts related to mood and anxiety disorders, which are crucial for the USMLE Step 2 CK examination. Understanding these disorders is essential for effective diagnosis and management. Specifically, we will focus on major depressive disorder, bipolar disorder, and differentiating between these two conditions. Additionally, we will cover anxiety disorders, including panic disorder, obsessive-compulsive disorder (OCD), and trauma-related disorders. By the end of this lesson, you should be able to confidently diagnose these disorders using clinical criteria, select appropriate pharmacotherapy and psychotherapy, and understand the nuances that differentiate unipolar from bipolar illness.

Learning Objectives

• Understand the definitions and features of major depressive disorder and bipolar disorder.
• Recognize various anxiety disorders, including panic disorder, OCD, and trauma-related disorders.
• Identify first-line pharmacotherapy and psychotherapy options for management.
• Diagnose mood and anxiety disorders utilizing clinical criteria.
• Differentiate unipolar from bipolar illness prior to treatment.

Mood Disorders

Major Depressive Disorder (MDD)

Major depressive disorder is characterized by a persistently low mood and loss of interest or pleasure in most activities. The criteria for diagnosis include:

• Depressed mood most of the day, nearly every day.
• Anhedonia, or diminished interest in all or almost all activities.
• Significant weight loss or gain, or decrease/increase in appetite.
• Sleep disturbances (insomnia or hypersomnia).
• Psychomotor agitation or retardation.
• Fatigue or loss of energy.
• Feelings of worthlessness or excessive or inappropriate guilt.
• Diminished ability to think or concentrate.
• Recurrent thoughts of death or suicide.

Example of Diagnosis:

Imagine a patient, John, a 32-year-old male, who presents with a persistent feeling of sadness for over two weeks, has lost weight, and reports significant fatigue. John also mentions he can’t sleep well and feels worthless. Based on the DSM-5 criteria, John's symptoms could lead to a diagnosis of major depressive disorder.

Bipolar Disorder

Bipolar disorder is characterized by mood swings that include emotional highs (mania or hypomania) and lows (depression). Key features include:

• Episodes of mania or hypomania are essential for diagnosis, characterized by an abnormally elevated mood, increased activity or energy, and other symptoms such as decreased need for sleep, racing thoughts, and impulsiveness.
• The depressive episode criteria for bipolar disorder are the same as those for major depressive disorder.

Differentiating MDD from Bipolar Disorder:

The key in differentiating MDD from bipolar disorder lies in the presence of manic or hypomanic episodes in bipolar patients. For example, assess Emily, a 29-year-old woman. Initially, she seems depressed, but on further questioning, she mentions experiencing a week of increased energy and decreased sleep where she felt “invincible.” This suggests a possible history of mania, indicating bipolar disorder over MDD.

Anxiety Disorders

Understanding Anxiety Disorders

Anxiety disorders encompass a range of conditions where excessive fear or anxiety interferes with daily activities. The primary anxiety disorders include:

1. Generalized Anxiety Disorder (GAD): Characterized by excessive anxiety and worry about various aspects of life.
2. Panic Disorder: Involves recurrent and unexpected panic attacks, which are sudden periods of intense fear that may include physical symptoms such as palpitations.
3. Obsessive-Compulsive Disorder (OCD): Defined by the presence of obsessions (intrusive thoughts) and/or compulsions (repetitive behaviors).
4. Post-Traumatic Stress Disorder (PTSD): Develops after exposure to a traumatic event, including symptoms like flashbacks and avoidance behaviors.

Example of Panic Disorder:

Consider Maria, a 27-year-old woman who presents to the emergency room with chest pain, rapid heartbeat, and a sense of impending doom. After ruling out cardiac events, she reveals this has happened several times without an obvious trigger, leading to a diagnosis of panic disorder.

Treatment of Mood and Anxiety Disorders

First-line Pharmacotherapy and Psychotherapy

Treatment modalities vary based on the disorder diagnosed:

• For major depressive disorder, SSRIs (Selective Serotonin Reuptake Inhibitors) like sertraline or fluoxetine are often first-line medications. Psychotherapy options include Cognitive Behavioral Therapy (CBT).
• In bipolar disorder, mood stabilizers such as lithium are crucial during manic episodes accompanied by atypical antipsychotics. Psychotherapy is supportive when the individual is stabilized.
• Anxiety disorders often respond well to SSRIs as well, with CBT considered the cornerstone of treatment.

Conclusion of Mood and Anxiety Disorders

In summary, understanding mood and anxiety disorders from a clinical standpoint is essential for diagnosis and treatment. Recognizing the symptoms and differentiating between related disorders significantly influences the choice of therapy. Being able to apply this knowledge in real-world clinical scenarios will enhance your medical practice.

Study Notes

• Major Depressive Disorder is characterized by a low mood and anhedonia with specific diagnostic criteria.
• Bipolar Disorder includes both manic and depressive episodes; differentiate from unipolar by assessing historical mood states.
• Anxiety disorders include conditions like GAD, panic disorder, OCD, and PTSD.
• First-line treatments for depression often involve SSRIs, while bipolar disorder may require mood stabilizers.
• Effective treatment often includes both pharmacotherapy and psychotherapy approaches.