English law suffers from a Latin hangover, as illustrated by the antiquated maxim de minimis non curat lex, literally meaning “The law does not concern itself with trifles”. As we shall see, psychiatric injury claims are not exempt from the de minimis principle. Injuries to a person’s mental health caused by the circumstances of his or her employment are frequently referred to by lawyers as ‘stress’ claims, which is an oxymoron as stress is not a psychiatric condition and therefore cannot give rise to a claim. Indeed, stress is an essential aspect of the human condition, and may just as equally be beneficial.
In truth, anxiety and depression are ordinary human emotions, so said Lord Bridge in McLoughlin v O’Brian  1 AC 410. He continued – “So, the first hurdle which a plaintiff claiming damages… must surmount is to establish that he is suffering, not merely grief, distress or any other normal emotion, but a positive psychiatric illness.” A decade later, in Hicks v Chief Constable of the South Yorkshire Police  All ER 65, he repeated “it is perfectly clear that fear by itself, of whatever degree, is a normal human emotion for which no damages can be awarded”. This was applied most recently by Mr Justice Stewart, who in the Kenyan Mau Mau litigation held that fear alone does not amount to personal injury: see Kimathi v FCO  EWHC 1305 (QB).
The term ‘nervous shock’ is one used by lawyers to describe a category of cases concerning those who have been traumatised by terrible events, whether as a primary victim or as a witness. Speaking in Alcock v Chief Constable of the South Yorkshire Police  4 All ER 907, Lord Ackner explained “‘Shock’, in the context of this cause of action, involves the sudden appreciation by sight or sound of a horrifying event, which violently agitates the mind. It has yet to include psychiatric illness caused by the accumulation over a period in time of more than gradual assaults on the nervous system.” Again, in Page v Smith  AC 155, Lord Keith defined it as “a reaction to an immediate and horrifying impact, resulting in some recognisable psychiatric illness. There must be some serious mental disturbance outside the range of normal human experience, not merely the ordinary emotions of anxiety, grief or fear.” A simple application of the principle was seen in Reilly v Merseyside RHA  6 Med LR 246, in which the unsuccessful claimant sought damages for claustrophobia and fear suffered when trapped in a lift. Ordinary emotional responses to unpleasant experiences of even the most serious type cannot found a claim for damages.
Likewise, distress brought about by the apprehension of a physical injury that has not materialised, and may never do so, is not actionable. This was the conclusion of the House of Lords in Rothwell v Chemical and Insulating Co Ltd  UKHL 39, in which it was held that the inhalation of asbestos dust and fibres leading to innocuous pleural plaques could not give rise to a claim for anxiety arising from concern over the possibility of suffering a future disease.
In the workplace context employers are under no obligation to protect their staff from normal reactions. An employee who suffers no more than distress at work, falling short of a psychiatric injury, cannot recover damages for negligence. As was explained in Fraser v State Hospitals Board for Scotland  ScotCS 191 (11 July 2000) “…the duty is only to take reasonable care to prevent psychiatric harm. It is not to protect an employee from unpleasant emotions such as grief, anger and resentment or normal human conditions such as anxiety or stress. These do not involve and form of ‘injury’ at all.”
In Hussain v Chief Constable of West Mercia Constabulary  EWCA Civ 1205 the claimant sought damages from the police for misfeasance in public office by failing to respond to his numerous calls for assistance. As it is tort that is non-actionable without proof of damage, the Court of Appeal was concerned with the question of whether the superimposition of transient “somatised physical symptoms of anxiety such as numbness and discomfort in the left arm and left leg” was sufficient. Perhaps unsurprisingly, it was unanimous in its conclusion that this did not amount to material damage.
The practical application of this principle is straightforward. To advance a claim it is necessary first to obtain expert psychiatric evidence diagnosing an illness recognised by a consensus of professional opinion, such as those contained within The World Health Organisation’s Classification of Mental and Behavioural Disorder (ICD-10), or the American Psychiatric Association’s statistical diagnostic criteria (DSM 5). Any psychiatric injury will suffice, however peculiar: Hinz v Berry  2 QB 40. In reality the psychiatrist’s first port of call is the patient’s medical history. Absent any past GP attendances presenting with symptoms of psychological illness it is likely that the individual’s condition will be seen as ‘sub clinical’, for which read non-actionable.
If there’s one thing that lawyers enjoy more than Latin then it’s laws that they can disregard. Having illustrated the rule, therefore, in the next post we shall examine its exceptions.