Differential Diagnosis

The patient's symptoms of anxiety, intrusive thoughts, and fear of making mistakes, along with feelings of depression and fatigue, suggest several potential diagnoses. Here is a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Generalized Anxiety Disorder (GAD): The patient's symptoms of excessive worry about everyday things, feeling nervous and anxious, and second-guessing herself are classic for GAD. The absence of compulsive symptoms to relieve anxiety also aligns with GAD, as it is characterized by persistent and excessive worry without the compulsions seen in Obsessive-Compulsive Disorder (OCD).

• Other Likely Diagnoses

  • Obsessive-Compulsive Disorder (OCD): Although the patient denies compulsive symptoms, the presence of intrusive thoughts about doing things in a certain way could suggest OCD. It's possible that the patient's symptoms are not fully recognized or disclosed.
  • Major Depressive Disorder (MDD): The patient reports feeling depressed, fatigued, and sometimes feeling like she has let herself and her family down, which could indicate depressive episodes. However, the stable appetite and lack of other depressive symptoms make this less likely as the primary diagnosis.
  • Adjustment Disorder with Anxiety: Given that the anxiety symptoms started last year, it's possible that the patient is experiencing an adjustment disorder in response to a specific stressor or change in her life, although the specific stressor is not mentioned.

• Do Not Miss Diagnoses

  • Bipolar Disorder: Although less likely given the information, bipolar disorder can present with anxiety and depressive symptoms. It's crucial to ask about manic or hypomanic episodes, which could have been missed or not reported.
  • Post-Traumatic Stress Disorder (PTSD): The presence of intrusive thoughts could also suggest PTSD, especially if the patient has experienced a traumatic event. The absence of reported trauma does not rule out PTSD, as patients may not always disclose traumatic experiences.
  • Thyroid Disorders: Thyroid dysfunction, particularly hyperthyroidism, can cause anxiety, fatigue, and mood changes. A physical examination and laboratory tests could help rule out this condition.

• Rare Diagnoses

  • Anxiety Disorder Due to Another Medical Condition: Certain medical conditions can cause anxiety symptoms. Although rare, conditions like pheochromocytoma, cardiovascular diseases, or neurological disorders could present with anxiety and should be considered if other symptoms or signs are present.
  • Neurodegenerative Disorders: In rare cases, neurodegenerative diseases can present with psychiatric symptoms, including anxiety. However, given the patient's age and the nature of her symptoms, this is less likely.