Introduction
New Zealand’s approach to personal injury is unique, operating as a dual system. The Accident Compensation Act 2001 (ACA 2001) provides comprehensive, no-fault cover for most personal injuries, and in return, section 317 of the Act bars common law claims for compensatory damages for injuries covered by the scheme. However, where an injury is not covered by the Act, the right to sue in negligence remains. This interface between the statutory scheme and the common law is particularly complex in the area of pure mental injury. The ACA 2001 provides cover for mental injury in only limited circumstances, leaving many who suffer such harm to seek a remedy through the restrictive and often inaccessible common law of negligence. This essay will argue that the current boundary between ACC-covered mental injury and common law claims is neither principled nor consistently workable. By examining the treatment of secondary victims and those suffering from work-related gradual process harm, it will be demonstrated that the existing framework creates arbitrary distinctions and significant gaps in redress. This suggests that reform is necessary to create a more coherent and equitable system for compensating mental injury.
The Legislative and Common Law Framework for Mental Injury
The ACA 2001 aims to provide rehabilitation and compensation to individuals who suffer a "personal injury" in New Zealand. Section 317(1) states that "No person may bring proceedings independently of this Act… for damages arising directly or indirectly out of… personal injury covered by this Act". The definition of "personal injury" is therefore critical. For mental injury, cover is narrowly defined. Under the Act, a "mental injury" is only considered a "personal injury" if it is:
- Suffered by a person because of a physical injury they have suffered (s 26(1)(c));
- Suffered by a person in circumstances where they have been the victim of certain criminal sexual offences (s 21 and Schedule 3); or
- A work-related mental injury caused by a single traumatic event (s 21B).
If a person’s mental injury does not fall into one of these three categories, it is not "covered by this Act," and the statutory bar does not apply. In theory, this allows the person to pursue a claim for damages in negligence. However, a common law claim for pure psychiatric harm faces significant legal hurdles. A claimant must prove they have suffered a recognisable psychiatric illness, as mere grief or distress is not sufficient (van Soest v Residual Health Management Unit [2000] 1 NZLR 179 (CA)). Furthermore, they must establish that the defendant owed them a duty of care to prevent such harm, a requirement the courts have historically been reluctant to impose broadly due to policy concerns about indeterminate liability. The interaction of these two systems at the margins of ACC cover creates outcomes that can be difficult to justify.
Boundary Scenario 1: Secondary Victims
A key area where the boundary proves problematic is in the case of "secondary victims"—individuals who suffer psychiatric harm from witnessing the death or injury of another person.
Under the ACA 2001, a person who witnesses a traumatic event is generally not covered for the resulting mental injury. The courts have held that witnessing an accident is not an "accident" to the witness themselves, and therefore does not cause a "personal injury" under the scheme (Queenstown Lakes District Council v Palmer [1999] 1 NZLR 549 (CA)). The mental harm is not consequential on a physical injury to the witness, nor does it typically fall into the other specific categories. The result is that the statutory bar in section 317 does not apply, and the secondary victim's only potential recourse is the common law.
In a common law negligence claim, the path for a secondary victim is exceptionally difficult. The leading New Zealand authority is van Soest, where relatives of patients who died during surgery sued the hospital for the psychiatric harm they suffered upon learning of the deaths. The Court of Appeal confirmed that to establish a duty of care, the psychiatric harm must be reasonably foreseeable to the defendant. While the Court declined to adopt the rigid control mechanisms from the English case of Alcock v Chief Constable of South Yorkshire Police [1992] 1 AC 310 (HL) (such as a "close tie of love and affection" and direct perception of the event), it still required a special degree of proximity between the claimant and defendant. The claims in van Soest ultimately failed because the claimants could not establish the necessary foreseeability of psychiatric illness, as opposed to normal grief.
This overall position is unprincipled. The availability of compensation for a secondary victim can depend arbitrarily on the nature of the event they witnessed. For example, if a person witnesses a loved one being negligently run over in a car crash, they receive no ACC cover and face an almost insurmountable barrier in the common law. However, if they witness a loved one being the victim of a serious assault, an event that is a criminal offence under Schedule 3 of the ACA 2001, they may be eligible for ACC cover under section 21. There is no clear principle justifying why one traumatised witness should have access to no-fault compensation while another is left with a near-impossible legal claim. This boundary is also not workable, as it creates a "justice gap" where most secondary victims, like those in van Soest, are left with no remedy at all. The common law does not function as a practical safety net but as a doctrinal barrier.
Boundary Scenario 2: Work-Related Gradual Process Injury
Another problematic boundary exists in the context of work-related mental harm. The ACA 2001 was amended in 2008 to introduce cover for "work-related mental injury" under section 21B. However, cover is tightly restricted to mental injury caused by a single, sudden event, or a series of events arising from a single source. The Act explicitly excludes mental injury caused by a gradual process, such as cumulative stress, harassment, or bullying over a period of time. The Employment Court has confirmed this narrow interpretation, holding that ongoing workplace bullying does not meet the "single event" threshold (I v The Chief Executive of the Ministry of Social Development [2019] NZEmpC 113).
Consequently, an employee who suffers a breakdown due to a long campaign of workplace bullying is not covered by ACC. The statutory bar is therefore lifted, and they may sue their employer in negligence. The common law duty of an employer to take reasonable care for the psychiatric health of their employees was recognised in Attorney-General v Gilbert [2002] 2 NZLR 342 (CA). However, the threshold for breach is very high. Following the English approach in Hatton v Sutherland [2002] ICR 613 (CA), the harm must be reasonably foreseeable to the employer. This generally requires the employer to be aware of a particular employee’s vulnerability or for there to be obvious signs of impending harm to health. Proving this, and then proving that the employer’s breach caused the illness, is a difficult, expensive, and stressful process for an employee who is already unwell.
This boundary is also unprincipled and unworkable. It draws an artificial distinction between different causes of work-related mental illness. An employee who suffers PTSD after witnessing a single horrific accident at work receives ACC cover. An employee who suffers a severe depressive disorder after months of systemic bullying by a manager is denied cover and forced into litigation. From the perspective of the injured employee, both have suffered a debilitating illness as a direct result of their employment. The legislative distinction lacks a coherent justification, treating physically analogous injuries differently; for instance, gradual process physical injuries like occupational overuse syndrome are covered by ACC.
Furthermore, the system is not workable because the common law fails to provide an effective remedy. The high foreseeability threshold means that many deserving claimants will fail. The result is another gap, where a category of genuine harm, demonstrably caused by the workplace, is effectively without a remedy. This is inconsistent with the core purpose of the ACC scheme, which was designed to replace the lottery of the tort system with comprehensive cover.
The Need for Reform
The scenarios above demonstrate that the current boundary between ACC and common law for pure mental injury is flawed. The distinctions it draws are often arbitrary and create inequitable outcomes. While the common law exists in theory to fill the gaps left by ACC, in practice its restrictive rules on duty and foreseeability mean that it is a remedy in name only for most claimants.
Reform is therefore needed. A principled approach would aim for greater consistency in the treatment of mental injury. One option is to expand ACC cover. For instance, the definition of "personal injury" could be amended to include secondary victim trauma arising from witnessing any accident, not just specific crimes. Similarly, section 21B could be broadened to cover mental injury caused by gradual processes like workplace bullying, bringing the treatment of mental harm in line with that of gradual physical harm. Such reforms would provide a more coherent and equitable system, ensuring that compensation is based on the fact of the injury rather than the arbitrary manner in which it was caused. While extending ACC cover would have significant financial implications that require careful consideration, the current framework's failure to provide a principled and workable system for many who suffer pure mental injury suggests that the status quo is untenable.
Conclusion
In conclusion, the boundary between ACC-covered mental injury and common law negligence claims is neither principled nor consistently workable. The limited scope of ACC cover, particularly concerning secondary victims and gradual process workplace harm, creates arbitrary distinctions that are difficult to justify. It leaves significant categories of individuals who have suffered genuine psychiatric harm with no realistic prospect of redress. The common law, while theoretically available, has proven to be an inadequate safety net due to its high and uncertain doctrinal hurdles. This "justice gap" undermines the comprehensive and equitable vision of the original ACC scheme. For New Zealand to have a truly fair system for personal injury, reform is needed. Expanding ACC’s criteria for mental injury would be a significant step towards creating a more principled, workable, and just boundary.
References
Attorney-General v Gilbert [2002] 2 NZLR 342 (CA).
I v The Chief Executive of the Ministry of Social Development [2019] NZEmpC 113.
Queenstown Lakes District Council v Palmer [1999] 1 NZLR 549 (CA).
van Soest v Residual Health Management Unit [2000] 1 NZLR 179 (CA).
Accident Compensation Act 2001.
Alcock v Chief Constable of South Yorkshire Police [1992] 1 AC 310 (HL).
Hatton v Sutherland [2002] ICR 613 (CA).
