When psychological symptoms appear after an accident, assault, medical event, or other alleged injury, the timing may suggest a relationship. Timing alone, however, does not establish whether the event caused a new condition, aggravated a preexisting condition, or coincided with other contributing factors. A personal injury psychological evaluation examines whether and to what extent the event contributed to the individual’s symptoms, diagnosis, or functional impairment. This analysis compares functioning before and after the event and integrates the clinical examination with records, testing, and other relevant information (Ciccone et al., 2024; Goodman-Delahunty & Foote, 2009; Piechowski, 2013).

The applicable legal standard depends on the jurisdiction and referral question. The psychologist addresses the psychological evidence relevant to the legal issue but does not determine the ultimate legal outcome. Forensic practitioners strive for accuracy, impartiality, fairness, and independence. They also consider plausible alternative explanations and clearly communicate the evidence, reasoning, and limitations underlying their opinions (American Psychological Association, 2013, Guidelines 1.01, 1.02, 9.01, and 11.01–11.04).

Why Do Diagnosis and Timing Alone Not Establish Causation?

A supported psychological diagnosis alone does not independently establish when the condition began, what caused it, how it affects functioning, or how much of the current presentation is attributable to a particular event. For example, an individual may meet diagnostic criteria for depression after a motor vehicle accident, but the diagnosis alone cannot determine whether the depression resulted from the accident, existed beforehand, developed in response to another stressor, or reflects several contributing factors (Goodman-Delahunty & Foote, 2009; Piechowski, 2013).

Research also demonstrates why diagnostic context must be evaluated carefully. In a study, clinicians diagnosed posttraumatic stress disorder more often when the same behavioral presentations followed a traumatic rather than mildly stressful event. This occurred even when the behaviors reflected depression or nondisordered distress. The study concerned hypothetical clinical diagnoses rather than forensic causation opinions, but it illustrates how a compelling causal context may influence diagnostic judgment (Weine & Kim, 2018).

How Does the Evaluator Analyze Causation?

1. Establishing the Pre-Incident Baseline

The evaluator examines the individual’s symptoms, treatment, diagnoses, stressors, and functioning before the alleged incident. Relevant areas may include employment, relationships, household responsibilities, recreation, and independence. A clear baseline helps distinguish a newly developed condition from the continuation, recurrence, or worsening of earlier difficulties (Goodman-Delahunty & Foote, 2009; Piechowski, 2013).

The absence of a prior diagnosis does not necessarily establish the absence of prior symptoms or impairment. Earlier medical and mental health records, treatment history, work performance, social functioning, and collateral information may provide a more complete picture of the person’s pre-incident condition (Ciccone et al., 2024; Piechowski, 2013).

The evaluator then considers when symptoms were first documented, how they changed, and whether they improved or worsened over time. The timeline may also identify changes in treatment, medical status, employment, relationships, or other circumstances that could have affected the presentation. Contemporaneous records are particularly useful because they document symptoms and functioning closer in time to the events being evaluated (American Psychological Association, 2013, Guidelines 9.01 and 9.02; Ciccone et al., 2024).

2. Identifying Documented Functional Changes

The evaluation examines whether the alleged event was followed by meaningful changes in work performance, relationships, household responsibilities, social activity, recreation, sleep, concentration, independence, or treatment needs. Functional evidence helps clarify whether the individual experienced a change extending beyond subjective distress or the presence of a diagnosis (Goodman-Delahunty & Foote, 2009; Piechowski, 2013). The evaluator also considers whether the claimed impairment is supported by records, behavioral observations, collateral information, and the individual’s documented activities. A diagnosis alone provides limited information about the nature and extent of functional impairment (Goodman-Delahunty & Foote, 2009; Piechowski, 2013).

3. Comparing Multiple Sources

A causation opinion should not rest solely on one interview, test result, or record. The evaluator compares the examinee’s account with medical and mental health records, psychological testing, behavioral observations, and collateral information when available. Important information should be corroborated whenever feasible (American Psychological Association, 2013, Guidelines 9.01 and 9.02; Ciccone et al., 2024).

Consistency across independent sources may strengthen an opinion. Significant discrepancies may require additional investigation and may limit the evaluator’s confidence in particular information. Discrepancies do not automatically establish dishonesty because records, recollections, and collateral accounts may also be incomplete or inaccurate. The evaluator must consider the quality, timing, and context of each source (American Psychological Association, 2013, Guidelines 9.01 and 9.02).

4. Evaluating Alternative Explanations

The evaluator considers factors other than the alleged incident that may explain or contribute to the current symptoms. Depending on the case, these may include:

The presence of another possible cause does not automatically eliminate the alleged incident as a contributing factor. Several factors may operate together. The evaluator must determine which explanations are supported by the evidence and seek information capable of distinguishing among plausible alternatives (American Psychological Association, 2013, Guidelines 1.02, 9.01, and 9.02; Goodman-Delahunty & Foote, 2009; Piechowski, 2013).

What Can Psychological Testing and Validity Assessment Clarify?

Psychological tests may provide information about current symptoms, personality functioning, trauma-related complaints, cognitive abilities, and response validity. Measures should be appropriate for the referral question and supported for their intended use. Interpretation should account for language, culture, disability, education, test-taking ability, and other individual or situational factors that may affect the results (American Psychological Association, 2013, Guidelines 10.02 and 10.03).

Testing does not independently identify the cause of a psychological condition. Test findings must be integrated with the interview, records, behavioral observations, functional evidence, and symptom timeline. Test-generated interpretations should be treated as hypotheses requiring further investigation rather than definitive proof of a psychological injury (Greenberg et al., 2003).

Validity assessment helps determine whether self-reported symptoms and test performance provide a sufficiently reliable basis for interpretation. Invalid findings may limit what can be concluded, but they do not automatically establish malingering. Conversely, valid symptom reporting or test performance does not independently prove onset or causation. Causation requires the additional analysis of prior functioning, symptom development, functional change, and alternative explanations (Bush et al., 2014; Greenberg et al., 2003; Sweet et al., 2021).

What Strengthens or Limits a Causation Opinion?

A causation opinion generally has a stronger foundation when the available evidence demonstrates:

• A reasonably clear pre-incident baseline
• A documented symptom and functioning timeline
• Meaningful changes following the alleged incident
• Reasonable corroboration across independent sources
• Interpretable psychological test findings
• Fair consideration of plausible alternative explanations

The opinion may be more limited when important records are unavailable, substantial gaps exist between the alleged onset and contemporaneous documentation, information cannot be corroborated, significant discrepancies remain unresolved, test findings are uninterpretable, or intervening events complicate the timeline. No single factor independently establishes or defeats causation (American Psychological Association, 2013, Guidelines 2.05, 9.01–9.03, and 10.02–10.03; Goodman-Delahunty & Foote, 2009; Piechowski, 2013).

What Can the Evaluation Ultimately Clarify?

Depending on the evidence, conclusions may fall within several broad categories:

A psychological evaluation cannot recreate every event or eliminate every possible explanation. Its purpose is to identify the conclusion most consistent with the available psychological evidence and clearly explain where the evidence remains insufficient.

What Questions Should Attorneys Ask?

When psychological causation is disputed, useful referral questions may include:

• Does the evidence support a psychological diagnosis or clinically significant symptoms?
• What was the individual’s psychological and functional baseline before the incident?
• Did the incident cause a new condition or aggravate a prior one?
• What other factors may have contributed to the current presentation?
• Are the reported symptoms and test results sufficiently valid for interpretation?
• What functional changes are supported by the evidence?
• What limitations affect the evaluator’s opinions?

Defining the referral questions helps keep the evaluation focused on the issues psychological evidence can address and reduces the risk of conclusions extending beyond the evaluator’s expertise or the available information.

Why Choose Vorwerk Forensic Psychology?

At Vorwerk Forensic Psychology, Inc., we conduct comprehensive and impartial personal injury evaluations for plaintiff and defense counsel. Our evaluations examine psychological diagnosis, functional impairment, causation, aggravation, alternative explanations, prognosis, treatment needs, and symptom and performance validity when relevant.

We integrate forensic interviews, psychological testing, records review, collateral information when appropriate, and relevant psychological research. Our goal is to provide clear, well-supported opinions identifying both the evidence and the limitations attorneys and courts need to evaluate.

For more information or to discuss whether a psychological evaluation may assist with causation issues in your case, please contact Vorwerk Forensic Psychology, Inc.