What is a suitable psych scale for rating the severity of post-traumatic stress disorder (PTSD) symptoms in a pregnant woman with a history of asthma and migraines?

PTSD Severity Rating Scales

Primary Recommendation

For rating PTSD severity in any population, including pregnant women, use the PTSD Checklist for DSM-5 (PCL-5), which is a validated 20-item self-report measure with strong psychometric properties (α = .94, test-retest reliability r = .82) that assesses all DSM-5 PTSD symptom criteria. 1

Gold Standard Clinical Interview

• The Clinician-Administered PTSD Scale (CAPS) remains the gold standard diagnostic interview for PTSD, providing structured assessment of frequency and intensity of all 17 symptoms using behaviorally anchored rating scales 2
• Multiple versions exist: CAPS-DX for diagnostic assessment over the past month, and CAPS-SX for symptom status over the past week for repeated assessments 2
• The CAPS-5 (updated for DSM-5) serves as the reference standard against which other measures are validated 3

Self-Report Measures: PCL-5 Details

Psychometric Properties

• The PCL-5 demonstrates strong internal consistency (α = .94), excellent test-retest reliability (r = .82), and robust convergent validity (rs = .74 to .85) 1
• In primary care samples, test-retest reliability ranges from adequate to excellent (.79-.94) 4
• The measure shows adequate fit with DSM-5's 4-factor model and superior fit with 6- and 7-factor models 1

Scoring and Interpretation

• Standard cutoff score: ≥33 indicates probable PTSD in general populations 5
• Psychiatric outpatient populations require a higher cutoff of ≥45 to balance sensitivity and specificity, as the standard cutoff produces excessive false positives in these settings 5
• Individuals with PTSD diagnosis average PCL-5 scores of 56.57, while those without PTSD average 33.56 in psychiatric samples 5

Minimal Important Difference

• PCL-5 change scores of 9-12 points represent clinically meaningful change in PTSD symptoms 4
• Change scores ≤5 points likely do not reflect reliable symptom change 4
• Distribution-based approaches indicate MID range of 8.5-12.5, while anchor-based approaches indicate 9.8-11.7 4

Abbreviated Versions for Time-Limited Settings

• 4-item and 8-item abbreviated PCL-5 versions show comparable diagnostic utility to the full 20-item scale, with high correlation to the total scale and good-to-excellent internal consistency 6, 3
• These abbreviated versions demonstrate adequate sensitivity for screening but lower specificity compared to the full scale 3
• The abbreviated measures are particularly useful in trauma center settings and routine clinical contexts where time is limited 3

Special Considerations for Pregnancy

Screening Context

• While the PCL-5 is appropriate for PTSD assessment, pregnant women should also be screened for depression and anxiety using pregnancy-validated tools 7
• The Edinburgh Postnatal Depression Scale (EPDS) is recommended for tracking mood and anxiety symptoms in pregnancy, as it is freely available and validated for perinatal use 7
• Women with PTSD history face increased risk for preeclampsia, creating a bidirectional relationship between PTSD and pregnancy complications 2

Clinical Implications

• PTSD is a known disruptor of neuroendocrine health and increases cardiovascular disease risk, particularly relevant in pregnancy 2
• Pregnancy itself can trigger PTSD symptoms or retraumatization, especially in women with previous traumatic birth experiences 8
• Low perceived coping ability during early pregnancy increases risk of postpartum PTSD symptoms 8

Additional Assessment Tools

• Symptom Checklist-90 (SCL-90): 90-item instrument evaluating broad psychological problems, useful for measuring treatment outcomes 2
• Symptom Questionnaire (SQ): Brief yes/no questionnaire assessing depression, anxiety, anger-hostility, and somatic symptoms 2

Common Pitfalls

• Avoid using the standard PCL-5 cutoff of 33 in psychiatric populations, as this produces high false-positive rates; use cutoff of 45 instead 5
• Do not rely solely on screening tools for diagnosis; follow positive screens with structured diagnostic interviews like the CAPS-5 5
• Polysomnography is not routinely indicated for PTSD assessment and may underestimate nightmare frequency 2
• In pregnant women, distinguish between general anxiety and pregnancy-specific anxiety, as the latter more strongly predicts adverse outcomes 7, 8