People who suffer from severe acne are at an increased risk of attempting suicide, the results of a new study indicate.

The study also found an additional risk may be present during and up to one year after treatment with isotretinoin (marketed here as Roaccutane), a commonly prescribed drug for severe acne. However, the researchers emphasised that this additional risk is most likely due to the acne itself, rather than the drug treatment.

Isotretinoin has been used to treat severe acne since the 1980s. The treatment can be effective but there have been reports linking the drug to depression and suicidal behaviour. However studies have had conflicting results.

Using the hypothesis that acne sufferers are at a higher risk of suicide, regardless of whether they are on isotretinoin or not, Swedish researchers investigated suicide attempts before, during and after isotretinoin treatment for severe acne.

They assessed the data of individuals who had been prescribed the drug between1980 and 1989, and linked these to hospital discharge and cause of death registers between 1980 and 2001.

The data involved 5,756 people, two in three of whom were male. The average age of men when they were first prescribed isotretinoin was 22 years, while for women, it was 27.

The study showed that 128 patients were admitted to hospital following a suicide attempt. The researchers also found that between one and three years before starting isotretinoin treatment, the number of suicide attempts increased. However the risks were highest within six months after treatment ended.

The team from the Karolinska Institute speculated that the increased risk after starting isotretinoin might be because patients whose acne and physical appearance improved following treatment were distraught if there was no improvement in their social life.

The researchers believe it is impossible to say for certain that the continued rise in suicide risk ‘is due to the natural course of severe acne, or to negative effects of the treatment'. However, while acknowledging that the increased risk could be ‘as a consequence of exposure to the drug', they believe ‘a more probable interpretation is that the underlying severe acne may best explain the raised risk'.

They stressed that attempted suicide is an uncommon event - one first suicide attempt would equate to 2,300 individuals being on isotretinoin - and this assumes that the entire increase in risk is due to the drug.

"The most important proactive measure to be taken would be to closely monitor all patients' psychiatric status, not only during treatment, but also for at least a year after treatment with isotretinoin," they concluded.

They added that it is not only important to monitor the mental health status of patients receiving isotretinoin, but also sufferers of severe acne who are not on treatment.

Details of these findings are published in the British Medical Journal.