Acne drug Roaccutane (Accutane, isotretinoin) has been officially linked to depression, study shows.

Since Roaccutane has been introduced for acne treatment in the early 1980s there have been numerous reports of depression and suicidal behaviour that occurred in some people who were taking Roaccutane.

In 2002, the makers of Accutane, Roche, won a case against a woman who claimed that popular acne drug Accutane caused her to suffer from depression. In a related story, the family of a 15-year-old boy who crashed a stolen plane into a Tampa high-rise building was unsuccessfully suing Roche for $70 million, accusing the medicine of prompting her son's suicide.

"Even the plaintiff's own experts had to admit that the theory that Accutane can cause depression is not accepted in the scientific community," said Roche's attorney, Harry Woods, at that time.

In the 20 years that Accutane has been available to patients with severe recalcitrant nodular acne, this is the first scientific evidence that shows that Accutane causes depression.

Roche, however, has placed a warning in the Accutane information that taking the medication may cause depression, psychosis and suicidal behaviour.

However, how exactly the drug causes depression was never established. Until now, when the new independent research by scientists at the universities of Bath and Texas at Austin have shown that isotretinoin (the scientific name of Accutane and Roaccutane) is indeed capable of causing depression and even suicidal behaviour in living creatures.

Scientists gave isotretinoin to mice over a period of six weeks, and then monitored the rodents' behaviour. Mice appeared to be less active and responded to stress less acutely. The mice were given Roaccutane in doses equivalent to that given to human adolescents.

"Establishing a link between the active molecules within the drug and a change in depression-related behaviour, albeit in mice, is an important step forward in our understanding of the effects of this drug in the wider context of brain function," said Dr. Sarah Bailey from the Department of Pharmacy and Pharmacology at the University of Bath.

"To date the only evidence for any link with patients has come from individual case reports and such patient data is complicated by the psychosocial effects of having severe acne."

Roaccutane belongs to a group of acne treatment medicines called retinoids. Topical retinoids have been a mainstay of treatment for acne for many years. These vitamin A-related compounds are known to affect development of the nervous system and cause severe damage to the fetus in pregnant women.