What is the recommended approach for diagnosing and treating mood disorders, including the use of standardized questionnaires like the Patient Health Questionnaire (PHQ)-9 for depression or the Mood Disorder Questionnaire (MDQ) for bipolar disorder?

Standardized Questionnaires for Diagnosing and Treating Mood Disorders

The recommended approach for diagnosing mood disorders should include validated screening instruments such as the PHQ-9 for depression and the MDQ for bipolar disorder, followed by appropriate diagnostic assessment and targeted treatment based on the specific mood disorder identified. 1

Screening Instruments for Mood Disorders

Depression Screening Tools

• Patient Health Questionnaire (PHQ-9):

  • 9-item self-report scale assessing major depressive disorder symptoms
  • Focuses on depressive symptoms and functional impairment
  • Traditional cutoff score is 10, but 8 is recommended for cancer patients 1
  • Pooled sensitivity of 0.78 and specificity of 0.87 at cutoff point 10 2
  • Better screening performance in primary care than secondary care settings 2
  • Valid diagnostic tool with positive predictive value of 59% in unselected primary care populations, increasing to 85-90% when prior probability is 30-40% 3

• Initial PHQ-2 Screening:

  • Two-item quick screen focusing on:
    1. Little interest or pleasure in doing things (anhedonia)
    2. Feeling down, depressed, or helpless (depressed mood)
  • If patient scores 2 or 3 on either item, proceed with full PHQ-9 1
  • Nearly 100% sensitivity among non-institutionalized older adults 1

• Other Validated Depression Screening Tools:

  • Hamilton Rating Scale for Depression (HAM-D): 17-item clinician-administered scale
    • Scores 7-17: mild depression
    • Scores 18-24: moderate depression
    • Scores ≥25: severe depression 1
  • Hospital Anxiety and Depression Scale (HADS): 14-item self-report measure
    • Score ≥8 indicates depression or anxiety 1
  • Center for Epidemiological Studies-Depression Scale (CES-D): 20-item scale
    • Scores ≥16 suggest moderate to severe depressive symptoms 1

Bipolar Disorder Screening

• Mood Disorder Questionnaire (MDQ):
  • Self-report screening instrument for bipolar spectrum disorders
  • Overall sensitivity of 61.3% and specificity of 87.5% across studies 4
  • More sensitive for bipolar I (66.3%) than bipolar II (38.6%) 4
  • At cutoff score of 7 items: sensitivity of 0.73 and specificity of 0.90 in psychiatric outpatient populations 5
  • Performance varies by setting - lower sensitivity in general population 4
  • Significantly outperforms general practitioner assessment for detecting mood disorders (sensitivity 0.8 vs 0.2) 6

Diagnostic Assessment Algorithm

1. Initial Screening:

   • Screen all patients at initial visit, at appropriate intervals, and with changes in clinical status 1
   • Use PHQ-2 as first-line depression screen
   • Use MDQ when bipolar disorder is suspected

2. Risk Assessment:

   • Immediately evaluate risk of self-harm or harm to others
   • Note: PHQ-9 item 9 assesses thoughts of self-harm - consider risk if endorsed 1

3. Secondary Assessment:

   • If PHQ-2 positive → Complete full PHQ-9
   • If PHQ-9 score ≥8 → Conduct comprehensive diagnostic assessment
   • If MDQ positive → Refer for specialized evaluation of bipolar disorder

4. Differential Diagnosis:

   • Rule out medical causes of depressive symptoms (e.g., thyroid disorders, medication side effects)
   • Evaluate for substance-induced mood symptoms
   • Consider delirium in older adults using Confusion Assessment Method 1
   • Distinguish between unipolar depression and bipolar disorder

Treatment Approach

1. Emergency Interventions:

   • For patients at risk of harm to self/others: immediate referral for emergency evaluation
   • Facilitate safe environment and one-to-one observation
   • Initiate appropriate harm-reduction interventions 1

2. Medical Management:

   • First treat medical causes of depressive symptoms (e.g., unrelieved pain, fatigue)
   • Address any underlying delirium (e.g., infection, electrolyte imbalance) 1

3. Treatment Selection:

   • For depression:
     • Pharmacologic interventions (antidepressants)
     • Non-pharmacologic interventions:
       • Psychotherapy
       • Psychoeducational therapy
       • Cognitive-behavioral therapy
       • Exercise 1
   • For bipolar disorder:
     • Mood stabilizers
     • Atypical antipsychotics
     • Psychoeducation and psychotherapy

Clinical Pearls and Pitfalls

• Pitfall: Relying solely on clinical judgment without validated screening tools can lead to significant underdiagnosis of mood disorders 6

• Pitfall: Using the MDQ in general population settings without adjusting thresholds may miss many cases of bipolar disorder 4

• Pitfall: Failing to distinguish between unipolar depression and bipolar disorder can lead to inappropriate treatment and potential worsening of symptoms

• Pitfall: Ignoring the self-harm item on the PHQ-9 may artificially lower scores and miss patients at risk 1

• Caution: Antidepressant selection should consider adverse effect profiles, potential drug interactions, prior treatment response, and patient preference 1

• Caution: The PHQ-9 may lose accuracy in patients with cognitive impairment 1