David Marshall, Partner
Solicitors Journal - 6 October 2009
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The development of a psychiatric illness is often a multi-factorial process. There may be more than one wrongdoer who each contributed to the development of the injury. There could also be a number of other non-negligent stressors which contributed to the development and/or severity of the injury – for instance problems in the claimant’s personal life such as bereavement, divorce or other trauma. And the claimant may have suffered from a psychiatric illness before and thus be more vulnerable than would generally be the case to further injury. These questions raise difficult questions of causation.
Material contribution
Unless public policy requires otherwise (e.g. Fairchild v Glenhaven Funeral Services Ltd & Ors [2002] UKHL 22), if there are a number of separate possible causes of the whole injury, but the claimant cannot establish that any one or more of them did so materially contribute to it, the claimant will usually fail to establish causation at all – as in Wilsher v Essex Area Health Authority [1988] 1 AC 1074. And if the claimant would have gone on to develop an illness at about the same time and of the same severity in any event, the claimant will not obtain compensation – as in the case of Hotson v East Berkshire Area Health Authority [1987] AC 750. However, neither of these scenarios usually applies in the case of a psychiatric injury where the effects of the various causes are likely to be cumulative and are obviously contributory to the overall severity.
The claimant must, however, show that the “breach of duty caused or materially contributed to the injury” and “material” in this context meant more than negligible (Bonnington Casting Ltd v Wardlaw [1956] AC 613). It is important that the medical experts understand the principle of material contribution which here displaces the usual ‘but for’ test on the balance of probabilities. It is of course entirely possible that expert evidence might establish that on the balance of probabilities as a result of the breach of duty the claimant sustained injury. If so, the claimant will obviously succeed. However, it is not necessary to establish such a degree of probability. If the court determines that the breach of duty was a more than negligible contribution to the illness the claimant will succeed.
The next question for the court is whether establishing material contribution means that the claimant recovers full compensation for the illness, notwithstanding other contributory causes, or whether the illness should be apportioned between the various contributory causes, so that the claimant only recovers part of the compensation in proportion to the relative contribution of the breach of duty. Much depends on whether the injury should be treated as ‘divisible’ or ‘indivisible’.
Apportionment
Two or more wrongdoers
If an indivisible injury is caused by two separate wrongdoers, but there is no other contributory factor, the claimant is entitled to compensation in full from either of the wrongdoers, with the court then being required to apportion the liability between the wrongdoers under the provisions of the Civil Liability (Contribution) Act 1978.
In Rahman v Arearose Ltd & University College London NHS Trust [2001] QB 351, the claimant suffered a serious assault at work for which his employer was liable. The hospital was then negligent in his subsequent medical treatment. He suffered psychiatric injuries which were caused by a combination of the trauma of the assault and the trauma of the loss of vision in one eye as a result of the operation. The psychiatric injury was treated as an indivisible injury. In determining the apportionment under the 1978 Act, the court is required to attribute blame between the two wrongdoers (his employer and the NHS Trust). This apportionment of the relative ‘blame’ of each defendant which is required under the 1978 Act is quite different from the more usual situation where the injury was caused partly by a breach of duty and partly by factors that do not give rise to any liability.
Two or more contributory causes
Assuming that the claimant can establish that the breach of duty did materially contribute to the injury, the next question is whether the responsibility for the injury can be apportioned between the various potent causes. If the injury is divisible then an apportionment will be made. The most obvious examples of this are industrial deafness where it is possible to measure the deterioration over a period of time (Thompson v Smiths Ship Repairers (North Shields) Ltd [1984] QB 405) or some kinds of asbestos exposure (Holtby v Brigham & Cowan (Hull) Ltd [2000] PIQR Q293). However, with other illnesses an injury is not divisible, but rather the various causes are cumulative. In Bailey v Ministry of Defence [2008] EWCA Civ 883, the claimant suffered brain damage as the result of a cardiac arrest suffered after she inhaled her own vomit. This was because she was in a weakened state contributed to by a negligent and a non-negligent cause. The Court of Appeal found that without the contribution of the breach of duty, she would not have been so weak. The breach was a material contribution and the claimant succeeded. The injury was seen as being indivisible and apportionment of the injury was not even argued at first instance or on appeal.
In the case of psychiatric injury caused by workplace stress, in Hatton v Sutherland [2002] EWCA Civ 76, the court held that the injury was divisible and needed to be ‘apportioned’ with the employer paying only for his share of the damage (Hatton Proposition 15). It should be noted that Hatton Proposition 15 is strictly speaking obiter as it did not fall to be decided in any of the appeals before the court. The Court of Appeal revisited this subject in Dickins v O2 plc [2008] EWCA Civ 1144. The employer had appealed a first instance decision in favour of the employee’s claim that she had suffered a nervous breakdown caused by overwork. The Court of Appeal rejected the appeal. However, the judge at first instance had allowed only 50 per cent of the claimant’s damages by way of apportionment in accordance with Hatton Proposition 15 between negligent and non-negligent causes.
In Dickins, these included a prior irritable bowel syndrome which might have been stress related, relationship problems (which may have been exacerbated by the work stress) and a subsequent flood which had required her to live in a hotel for nine months and may have delayed her recovery. This apportionment finding was not appealed by either side.
However, the Court of Appeal proceeded, obiter, as the point was not argued and was not therefore the subject of the appeal, to critique Hatton Proposition 15 on apportionment. Smith LJ revisited the question of whether psychiatric injury is in fact a ‘divisible injury’ allowing for apportionment, saying: “I am doubtful of the applicability of this type of approach to a case of psychiatric injury where there are multiple causes of the breakdown.”
At first sight, it might be thought that Hatton Proposition 15 on apportionment would continue to be applied as it forms part of a judgment that has been approved by the House of Lords. However, while generally giving support for the propositions of Hale LJ, the House of Lords expressly declined to endorse Hale LJ’s approach on apportionment in Barber v Somerset County Council [2004] UKHL 13. So the issue of apportionment has been considered separately by two distinguished Lady Justices of Appeal with great experience in personal injury law. Both comments are obiter. The issue will have to be decided in an appropriate case in the future, possibly by the House of Lords.
In the meantime, claimants should be wary of accepting arguments on apportionment of injury and should argue that as an indivisible injury the whole of the injury should be compensated by the employer.
Acceleration
Although the starting point should be that if the claimant can establish that the breach of duty was a material contribution to an indivisible psychiatric injury he should recover full compensation, the court is still entitled to ask whether the compensation should still be reduced by reason of ‘acceleration’ rather than ‘apportionment’.
If, prior to the employer’s breach of duty, the claimant had a history of psychiatric injury or a pre-existing vulnerability then the court may treat the employer’s breach not as the sole cause of the claimant’s entire loss, but rather as the trigger which accelerates the onset of an illness that would have developed in any event (Hatton Proposition 16).
Dealing with an ‘acceleration’ of injury is common for personal injury lawyers (e.g. where a negligent act accelerates back problems which already exist, whether or not they are then symptomatic, through degenerative change, see Kenth v Heimdale Hotel Investments Limited [2001] EWCA Civ 1283). In Dickins v O2, while doubting Hatton Proposition 15 on apportionment of damages, Smith LJ stressed: “It may well be appropriate to bear in mind that the claimant was psychiatrically vulnerable and might have suffered a breakdown at some time in the future even without the tort. There may then be a reduction in some heads of damage for future risks of non-tortious loss.”
There is therefore a complex interplay between ‘apportionment’ between different factors contributing to the injury and the assessment of the likelihood that the claimant would have become ill in any event (‘acceleration’). It is submitted that Smith LJ’s approach is the better one, even though, as she points out: “... ultimately the result of a different approach might not have been very different”.
Whether acceleration should apply or not in a particular case is principally a question of expert medical evidence. Care should be taken to direct the experts to properly consider this question. In MG v North Devon NHS Primary Care Trust [2006] EWHC 850 (QB), the claimant succeeded in her claim for damages against her employer for mishandling her return to work following a breakdown, but the judge reduced her compensation by 20 per cent “to reflect the claimant’s vulnerability following her [first] breakdown”. However, it is not inevitable in the case of a vulnerable employee that the damages will be reduced. In Moore v Welwyn Components Limited, a conjoined appeal in Hartman [2005] EWCA Civ 06, the court declined to find ‘acceleration’ on the basis that previously the claimant had always quickly recovered from his psychiatric injury, whereas this bullying had led to a disorder of an entirely different order. However, applying one discount for acceleration is more just than double-discounting for both apportionment and acceleration which was often the practical effect of the Hatton approach.
Psychiatric injury - key points
In psychiatric injury cases (including stress at work claims):
- the injury will normally be an 'indivisible' injury; and
- provided that the breach is more than negligible, the breach will be a 'material contribution' and thus satisfy the 'but for' test.
Hatton Proposition 15 (apportionment):
- was not endorsed by the House of Lords in Barber;
- is doubted by Smith LJ in Dickins;
- the comments on apportionment in both Hatton and Dickins are obiter, but Dickins is to be preferred; and
- 'acceleration' of injury by reason of vulnerability (Hatton Proposition 16) can still apply, but consider the particular facts with care.
David Marshall is a personal injury and employment specialist and a partner with Anthony Gold Solicitors. He is the author of 'Compensation for Stress at Work' (Jordans 2009). For further information email David Marshall or call 020 7940 4000.
