Page "M'Naghten rules" Paragraph 20

: In our judgment, stress, anxiety and depression can no doubt be the result of the operation of external factors, but they are not, it seems to us, in themselves separately or together external factors of the kind capable in law of causing or contributing to a state of automatism.

They constitute a state of mind which is prone to recur.

They lack the feature of novelty or accident, which is the basis of the distinction drawn by Lord Diplock in R v Sullivan 1984 AC 156, 172.

It is contrary to the observations of Devlin J., to which we have just referred in Hill v Baxter 1958 ) 1 QB 277, 285.

It does not, in our judgment, come within the scope of the exception of some external physical factor such as a blow on the head or the administration of an anaesthetic.