The expert’s task is not to choose one event and disregard the rest. Psychiatric conditions commonly emerge from an interaction between vulnerability, stressful experiences, physical symptoms and changes in daily life. The medico-legal question is what difference the index event made within that sequence.
Timing is the beginning, not the answer.
A condition that develops after an accident may have been caused by it. Sequence alone does not establish causation. The expert should first construct a reliable chronology. When did the initial symptoms appear? What form did they take? Was there a period of improvement? Did the presentation change after a later bereavement, redundancy, relationship breakdown or financial crisis?
The distinction can be significant. Travel anxiety beginning immediately after a collision may be readily connected to the event. A broad depressive episode beginning after dismissal from work several months later requires a different analysis, even where the accident contributed to the circumstances surrounding the dismissal.
NICE recommends that an assessment of depression should consider more than symptom count. It should examine previous history, duration, functional impairment, relationships, employment, debt, isolation and recent or earlier stressful or traumatic life events. That is good clinical practice and equally important in a medico-legal assessment. A report that records only the accident and the current symptoms may miss the part of the history that explains why the condition began, changed or persisted.
Separate the onset from the later deterioration.
An accident may cause the initial psychiatric injury without explaining every later development.
A claimant might develop a specific travel phobia following a collision and subsequently experience depression after losing employment. The loss of work may itself have occurred because the claimant could no longer drive, in which case it may form part of the accident-related sequence. Alternatively, the redundancy may have affected an entire department and would have occurred regardless of the accident. those histories should not produce the same opinion.
The expert should ask whether the later event was independent, partly connected to the accident or a consequence of the claimant’s accident-related condition. The answer may affect diagnosis as well as causation. What began as travel anxiety may later become a broader adjustment disorder or depressive episode. There is no need to force the whole presentation into one diagnosis if the clinical history supports more than one process.
Pre-existing vulnerability is not the same as an active disorder.
The claimant may have experienced earlier depression, anxiety, trauma or difficult life circumstances. That history may show a susceptibility to recurrence. It may also establish that significant symptoms were already present before the index event. Those are different findings.
A claimant who experienced depression ten years earlier but had remained well and fully functional may have had a vulnerability without an active condition. Another claimant may have been taking medication, receiving counselling and struggling at work immediately before the accident.
The expert should establish the pre-accident baseline rather than merely list earlier diagnoses. What symptoms were present? What treatment was being received? How was the claimant functioning? Was the condition stable, improving or already deteriorating?
The accident may have caused a new disorder, aggravated an active one, triggered a recurrence or brought forward an episode that would probably have occurred later. Each formulation needs an explanation grounded in the chronology and records.
Later stress does not automatically break the connection.
It is sometimes assumed that the appearance of a major later life event removes the accident as a cause, that is too simple.
A bereavement or relationship breakdown may become the dominant reason for continuing symptoms while the accident remains responsible for the original condition. Several events may also operate together, with no single event providing a complete explanation.
Conversely, the fact that the accident came first does not mean it remains responsible indefinitely. A claimant may have substantially recovered before an unrelated crisis produced a new episode. In that situation, extending accident-related causation through the later condition may not be medically supportable.
The report should identify changes in symptom type, severity and function around each event. A clear improvement followed by a marked deterioration after an unrelated stressor may carry considerable weight. Continuous symptoms with no meaningful recovery may suggest that the later event aggravated an existing accident-related condition rather than replacing it.
The expert is not required to find one exclusive cause. They are required to explain the relative medical significance of the events as far as the evidence permits.
Avoid percentages without a clinical foundation.
Solicitors sometimes ask the expert to divide responsibility between the accident, bereavement, employment problems and pre-existing vulnerability, a neat percentage may be attractive. It is rarely clinically measurable.
There may be cases in which a broad division can be explained, particularly where distinct conditions or periods can be identified. The expert might conclude that the accident caused travel anxiety, while a later depressive episode was predominantly associated with bereavement and financial pressure. That is different from stating that the accident caused precisely 40% of the claimant’s overall psychiatric disability.
Where the evidence does not permit mathematical division, the report should say so. Practice Direction 35 requires experts to consider facts that may detract from their opinions and to state any qualification where a definite conclusion cannot be reached. Uncertainty should not be disguised as arithmetic.
Records must be read as a sequence.
Individual medical entries can be misleading when removed from their context.
A GP record stating “low mood since accident” may reflect the claimant’s account rather than the clinician’s independent causation opinion. A later entry identifying marital or financial stress may not mean that the accident was irrelevant. Treatment notes may focus upon the issue discussed during that session rather than every factor contributing to the condition.
The expert should compare contemporaneous records, medication changes, treatment referrals, employment documents and the claimant’s account at examination. Attention should be paid to what happened before and after each alleged stressor. The report must distinguish reported history from established documentary fact. The GMC requires expert evidence to be accurate and not misleading, to include relevant information and to make clear where conclusions are qualified because evidence conflicts or is insufficient.
A record should not be treated as infallible, but adverse entries cannot be ignored because they make the opinion less straightforward.
Prognosis depends upon what is maintaining the condition.
Life events complicate prognosis as well as causation, a condition initially caused by an accident may continue because of unemployment, debt, chronic pain, family conflict or social isolation. These maintaining factors may reduce the likelihood of recovery even if they were not present when the disorder began.
Treatment may need to address the current presentation rather than the original trigger alone. Trauma-focused work may be appropriate for continuing accident-related symptoms, while practical, interpersonal or employment difficulties may require different support.
The expert should explain whether recovery depends upon treatment, improvement in external circumstances or both. A prognosis based solely upon the date of the accident may be unrealistic where the claimant’s life has changed substantially since then.
The court decides the legal consequence.
The psychiatric expert should provide a clinical analysis, not assume the role of the judge.
The report should state the diagnosis, identify the probable contributing factors and explain what the claimant’s condition would likely have been without the index event. Where the opinion depends upon disputed facts, alternative conclusions may be necessary.
The expert may say that the accident probably initiated the condition, that a later event became the main cause of deterioration, or that the available evidence does not allow the influences to be separated reliably.
Civil experts must remain independent, take account of all material facts and identify when their opinion is provisional or qualified. Their duty is to assist the court rather than advance the position of the party instructing them.
Life events do not make psychiatric causation impossible. They make simplistic causation unsafe.
The question is rarely whether the accident or the later stressor caused the condition. It is often how the claimant’s psychological state developed through both, and which parts of the eventual disability would probably have existed had the accident never occurred.
A defensible opinion does not remove complexity from the history. It explains what that complexity means.
