While no one who has experienced it has happy memories of acne, most of us recall it as a mild and fleeting irritation of adolescence. Most teenagers suffer to some extent from spots, but the worst usually passes with age and we do not think of it as a serious medical problem.

This perception explains to a large extent why stories about a possible side-effect of Roaccutane, a treatment for acne, look particularly shocking. In several dozen cases, young adults with no history of mental illness have committed suicide after starting the drug, while others have developed severe depression. Many bereaved parents blame Roaccutane and some have called for it to be withdrawn.

This reaction is quite understandable. For most people, the idea that treating acne might be worth even a remote risk of psychiatric problems and suicide seems unfathomable. The evidence for a connection is largely circumstantial, and if there is one it is rare: the World Health Organisation reports 720 cases of mental illness and 84 suicides and suicide attempts, among 13 million people treated with Roaccutane since 1982. But it is easy to see why parents make it, and research has this week suggested a potential biological cause. Mice given the drug show increased signs of depression-linked behaviour, a study at the University of Bristol found.

This is important work that needs to be followed up.

A potential side-effect as serious as suicide cannot be ignored. There are good reasons, though, to pause before condemning Roaccutane as a “danger drug”, as the Daily Mail did on Tuesday, or calling for a ban. Its withdrawl would likely do more harm than good and could even cause more suicides than it prevents.

What tends to be forgotten in discussion of this medicine is the devastating effect that acne can have. It does not always amount to just a few zits: in its severe form it can last for years, destroying the confidence and psychological health of those who suffer. It tends to strike at an emotionally vulnerable age, making some young adults so self-conscious that they avoid social contact with their peers.

Acne is well-established as a contributory factor in itself to anxiety, depression and even suicide. This, indeed, is one of the reasons why it has been so hard to establish whether Roaccutane has a negative impact on mental health: such problems are common already among the population that takes it, making any signal difficult to separate from background noise.

What is not in doubt is that Roaccutane works. The drug is effective in between 80 and 90 per cent of those who take it. Many patients say, without exaggeration, that it has changed their lives, saving them from depression and eliminating suicidal thoughts.

It is also the subject of more existing safeguards than the vast majority of other drugs. Along with the possible link to depression, Roaccutane can cause severe birth defects if taken during pregnancy. For these reasons it can be prescribed only by a consultant dermatologist, not by a GP, and only to patients with severe acne, not those with less serious complexion problems. Even though its impact on mental health is not proven, the British Association of Dermatologists recommends a psychiatric assessment before it is approved. This is not a drug that is given out lightly; it is a powerful medication for treatment of a serious disease.

None of this means that the link to depression and suicide should not be more thoroughly investigated. It must be, not least because if there is a causal effect it might be possible to monitor patients for warning signs or to predict who is most at risk. Exaggerations of the danger, however, pose a greater hazard than any that might come with the drug itself, denying people with acne an opportunity to transform their quality of life.

Mark Henderson is the Science Editor of The Times