Life Events Checklist for DSM-5 (LEC-5) and Criterion A

Foundational Context

The LEC was originally developed as part of the DSM-IV PTSD assessment initiatives, with strong psychometric findings documented by Gray et al. (2004). The LEC-5 version aligns with updated DSM-5 trauma criteria. Its purpose is not to diagnose PTSD but to identify whether an individual has experienced a potentially qualifying traumatic event.

Criterion A—exposure to actual or threatened death, serious injury, or sexual violence—is the foundation of PTSD diagnosis. The LEC-5 ensures that clinicians accurately identify trauma exposure types and modes before interpreting PTSD symptoms. The measure is widely used in trauma therapy, primary care, military and veteran services, emergency response, and research.

What the Assessment Measures

The LEC-5 assesses lifetime exposure to traumatic events across 17 predefined categories plus an “other” item. For each event, respondents indicate the nature of their exposure:

• Happened to me
• Witnessed it
• Learned about it happening to a close family member or friend
• Part of my job (e.g., first responders)
• Not sure
• Doesn’t apply

Events span natural disasters, accidents, interpersonal violence, combat, and severe injury. The tool provides a structured map of the respondent’s trauma exposure profile.

Interpretation Guidelines

The LEC-5 does not produce a numerical score. Interpretation is qualitative and based on types and modes of exposure, helping clinicians determine whether PTSD assessment criteria are met.

Key interpretation principles:

• Identify whether at least one event meets DSM-5 Criterion A.
• Assess the respondent’s mode of exposure (direct, witnessed, learned, occupational).
• Use follow-up questions to clarify ambiguous exposures or “not sure” responses.
• The LEC-5 should always be paired with symptom assessments such as the PCL-5 or a structured clinical interview.

Interpretation Notes:

• The LEC-5 identifies potential Criterion A events; clinicians must confirm details.
• Multiple exposures may increase risk for PTSD but do not change Criterion A requirements.
• Occupational exposure is qualifying only if the individual experienced repeated or extreme exposure to aversive details (e.g., first responders).
• Non-professional media exposure (e.g., news, videos) is not considered Criterion A.

Criterion A (DSM-5) Overview

Criterion A determines what counts as a qualifying traumatic event for PTSD diagnosis.

A Criterion A trauma must involve:

1. Actual or threatened death,
2. Serious injury, or
3. Sexual violence

and occur through one or more of the following:

• Direct exposure
• Witnessing in person
• Learning that it happened to a close family member or friend (must be violent or accidental)
• Repeated or extreme exposure to aversive details of trauma (e.g., emergency responders)

Exclusions:

• Indirect, non-professional exposure through media does not satisfy Criterion A unless job-related.

Psychometric Properties

Reliability

• Good test–retest reliability across trauma-related studies
• Stable identification of exposure categories over time
• Consistent results across diverse populations

Validity

• Strong convergent validity with structured trauma interviews
• Good discriminant validity compared to general stress or non-trauma events
• High utility in both civilian and military/veteran samples
• Foundational psychometric support from Gray et al. (2004)

Administration Considerations

• Should be administered before symptom-based PTSD evaluations
• Works well as part of intake workflows in medical, mental health, and trauma-focused care
• Follow-up questioning is essential for ambiguous responses
• Can be administered verbally or via self-report
• Helps identify whether symptoms are linked to qualifying trauma exposures

Limitations

• Does not measure PTSD symptoms or severity
• Not diagnostic; requires clinical follow-up
• Respondent recall may be influenced by avoidance, dissociation, or memory gaps
• “Not sure” responses may require sensitive, trauma-informed clarification