A previous mental-health diagnosis does not automatically explain the claimant’s current symptoms, and it does not prevent a later event from causing genuine psychological harm. It is one part of the pre-accident history that must be examined carefully rather than used as a convenient reason either to reject or accept causation.
A diagnosis is not a permanent state.
Mental-health conditions can remit, recur, change in severity or be replaced by a different presentation. A claimant who experienced depression several years earlier may have recovered fully and returned to unrestricted work and family life. Another may have remained on medication with continuing symptoms immediately before the index event. The diagnostic label may be identical, but the pre-accident baseline is not.
The expert should establish when the earlier condition began, how long it lasted, what treatment was provided and whether recovery occurred. Function is often more informative than the diagnosis alone. Was the claimant working? Were they socially active? Did they require continuing support? Were there further episodes or periods of sickness absence?
NICE advises that assessment of depression should consider previous episodes, coexisting conditions, past treatment and the person’s response to that treatment. It also recognises that people with a past history of depression may be at increased risk of further difficulties.
The expert should therefore distinguish a historical diagnosis from an active disorder.
Check what the original diagnosis was based upon.
The appearance of a diagnosis in the records does not make it infallible. Some entries reflect a detailed specialist assessment. Others may record a provisional diagnosis made during a brief GP consultation. Diagnostic codes can be copied forward long after symptoms have settled. A prescription may continue for relapse prevention rather than because the claimant remains significantly unwell.
The expert should consider who made the diagnosis, what symptoms were recorded and whether the available information supports the label. Earlier counselling notes, psychiatric correspondence and medication reviews may be more informative than a problem-list entry.
This does not permit the expert to rewrite the earlier clinician’s opinion simply because another diagnosis now seems preferable. The report should state what was recorded and explain any uncertainty about its significance.
A previous diagnosis of depression should not casually become “a longstanding depressive disorder” unless the history supports that description.
Medication does not settle the baseline.
Antidepressant or anti-anxiety medication is relevant, but its meaning requires context. The claimant may have continued medication while remaining well. The dose may have been stable for years, increased shortly before the accident or restarted only afterwards. The medicine may also have been prescribed for another condition.
The expert should examine prescribing dates, dose changes, reviews and the reasons documented for continuing treatment. Stopping medication is not proof of recovery, just as taking medication is not proof of active psychiatric disability. The same caution applies to therapy, and a referral may not have resulted in attendance. A completed course may have produced substantial improvement. Repeated referrals may suggest continuing or recurrent difficulty.
Treatment history should inform the baseline rather than replace it.
Ask what changed after the index event.
The central question is not whether the claimant had ever experienced mental ill-health. It is what difference the index event made.
The event may have caused a new condition that is clinically distinct from the earlier diagnosis. A claimant with a remote history of depression may develop a specific travel phobia following a collision. Another may experience a recurrence of depression after an injury disrupts employment, sleep and independence.
The event may also aggravate an active condition or temporarily increase symptoms that would otherwise have continued at a lower level. The expert should compare the nature, severity and function of the pre- and post-event presentations. Did the symptoms change in character? Was there a new pattern of avoidance, panic or intrusive recollection? Did medication increase? Was further treatment required? Did work or ordinary activity alter?
Temporal sequence is relevant but not sufficient. Symptoms beginning after an event may still have another explanation, particularly where bereavement, workplace difficulty, relationship breakdown or physical illness occurred during the same period.
Previous vulnerability does not defeat causation.
A person with an earlier mental-health diagnosis may be more susceptible to a later episode. That susceptibility does not mean that the later condition would have developed at the same time without the index event. The expert should distinguish vulnerability from inevitability.
A claimant may have remained well for years before a particular accident triggered a recurrence. In another case, records may show a worsening condition and planned treatment immediately before the accident, suggesting that a further episode was already developing.
The opinion should address what would have happened without the index event. Would the claimant have remained stable, experienced a recurrence at some later stage or continued to require treatment in any event? Exact predictions may not be possible. Where the evidence supports only a range of possibilities, the expert should say so rather than create false precision.
Do not assume the claimant concealed the history.
Claimants do not always report earlier mental-health difficulties accurately.
Some may regard a remote episode as irrelevant. Others may not recognise counselling, medication or work-related stress as a psychiatric history. Memory may be poor, particularly where the earlier period was distressing. There will also be cases in which relevant history has been deliberately withheld.
The expert should identify the inconsistency and give the claimant an opportunity to explain it. The report should record both the current account and the documentary evidence. A failure to disclose an earlier diagnosis may reduce confidence in aspects of the history. It does not automatically prove dishonesty or invalidate the current condition.
The GMC requires expert reports to be accurate, not misleading and based upon all relevant information. Experts must also distinguish facts from professional opinion and remain within their competence. Practice Direction 35 similarly requires consideration of material facts that may weaken an opinion.
Avoid diagnostic carry-over.
A previous diagnosis should not be copied into the current report without reassessment.
The present symptoms may no longer satisfy the earlier diagnosis. They may be better explained by another condition, ordinary distress, chronic pain or unrelated life events. Conversely, a claimant previously diagnosed with anxiety may now present with a more significant depressive or trauma-related disorder.
NICE identifies a range of PTSD features, including re-experiencing, avoidance, hyperarousal, altered mood and functional impairment. Those symptoms must be assessed in the current presentation rather than assumed from a historical label. Where diagnosis falls outside the first expert’s field, further specialist evidence may be required.
Prognosis must reflect recurrence risk.
Previous episodes may affect prognosis even where the claimant was well before the event.
A history of recurrence, incomplete recovery or repeated treatment may justify a more guarded view. A single remote episode followed by years of stable function may carry less weight. The expert should explain whether the previous condition is likely to lengthen recovery, increase the risk of future relapse or require treatment that would have been needed regardless of the index event.
A previous mental-health diagnosis should neither be ignored nor allowed to dominate the report. The expert’s task is to determine what the diagnosis meant before the event, what changed afterwards and which part of the current presentation can be attributed to the event under consideration.
The relevant question is not, “Has this claimant been mentally unwell before?”
It is, “What was their condition immediately beforehand, and what additional difference did this event make?”
