How often should a patient complete the GAD‑7 (Generalized Anxiety Disorder‑7), PHQ‑9 (Patient Health Questionnaire‑9), MDQ (Mood Disorder Questionnaire), and CASE‑I (Clinical Assessment of Severity of Episodes) scales, and when should laboratory monitoring be performed?

Frequency of Symptom Screening Tools and Laboratory Monitoring

Screen patients with PHQ-9 and GAD-7 at initial visit, then at appropriate intervals during treatment (typically every visit or every 2-4 weeks during active treatment), at 3,6, and 12 months post-treatment, and whenever there are changes in clinical status such as symptom worsening, treatment changes, or life stressors. 1, 2

Screening Tool Administration Schedule

PHQ-9 and GAD-7 Timing

The ASCO guidelines provide the most comprehensive framework for when to administer these measures 1, 2:

• Initial diagnosis/first visit - Establish baseline
• Start of treatment - Document pre-treatment severity
• Regular intervals during active treatment - Monitor response (typically every 1-4 weeks depending on severity and treatment intensity)
• 3,6, and 12 months after treatment completion - Track sustained response
• At recurrence or symptom worsening - Detect relapse early
• During transitions - Such as medication changes, therapy completion, or major life events
• When approaching end-of-life care (if applicable)

For patients in active treatment showing moderate to severe symptoms (PHQ-9 ≥10 or GAD-7 ≥10), weekly to biweekly monitoring is appropriate until symptoms improve to mild range. 1, 2, 3

MDQ (Mood Disorder Questionnaire) and CASE-I

The evidence provided does not specifically address MDQ or CASE-I frequency. However, based on the bipolar disorder guideline principles 4:

• MDQ should be administered when bipolar disorder is suspected - particularly if patient shows treatment-resistant depression, family history of bipolar disorder, or hypomanic symptoms
• Reassess if new manic/hypomanic symptoms emerge during treatment
• Not needed for routine monitoring in patients with established unipolar depression or anxiety

Laboratory Monitoring

When Labs Are Appropriate

Laboratory monitoring is NOT routinely indicated for depression or anxiety screening itself, but IS required when specific medications are prescribed. 4

Medication-Specific Lab Schedules

For Lithium (if prescribed for bipolar disorder) 4:

Baseline labs:

• Complete blood count
• Thyroid function tests (TSH, T4)
• Urinalysis
• Blood urea nitrogen and creatinine
• Serum calcium
• Pregnancy test (females of childbearing age)

Ongoing monitoring (every 3-6 months once stable):

• Lithium levels
• Renal function (BUN, creatinine)
• Thyroid function
• Urinalysis

For Valproate/Divalproex (if prescribed) 4:

Baseline:

• Liver function tests
• Complete blood count
• Pregnancy test (females)

Ongoing (every 3-6 months):

• Serum drug levels
• Hepatic function
• Hematological indices

For Atypical Antipsychotics (if prescribed) 4:

Baseline:

• Body mass index (BMI)
• Waist circumference
• Blood pressure
• Fasting glucose
• Fasting lipid panel

Ongoing monitoring:

• BMI: Monthly for first 3 months, then quarterly
• Blood pressure, fasting glucose, lipids: At 3 months, then yearly
• White blood cell count weekly for clozapine (first 6 months), then biweekly 5

Important Caveats

Labs are only indicated when medical causes of psychiatric symptoms are suspected (e.g., thyroid dysfunction, hypoglycemia, electrolyte imbalances) or when specific psychotropic medications require monitoring. 1, 6

Do not order routine labs for patients being treated with psychotherapy alone or SSRIs/SNRIs without specific clinical indication.

Practical Implementation Algorithm

1. First visit: Administer PHQ-9 and GAD-7; consider MDQ if bipolar features present
2. If scores indicate moderate-severe symptoms (≥10): Repeat every 1-2 weeks during treatment titration
3. If scores indicate mild symptoms (5-9): Repeat every 2-4 weeks or monthly
4. Once in remission: Repeat at 3,6, and 12 months, then as clinically indicated
5. Labs: Only order if prescribing medications requiring monitoring (see schedules above) or if medical causes suspected

The PHQ-9 and GAD-7 are strongly correlated (correlation coefficient 0.74), so if resources are limited, prioritize the scale matching the primary diagnosis. 7 However, both should ideally be used as they can identify distinct symptom patterns, particularly the somatic versus cognitive-affective domains. 8, 9, 10