Shire Pharmaceuticals Group plc announced its treatment for Attention Deficit Hyperactivity Disorder (ADHD), Adderall XR (mixed salts of a single-entity amphetamine) has been approved by the US FDA as a once-daily treatment for adults.

In addition, the FDA has confirmed to Shire that new 40mg, 50mg and 60mg dose strengths of Adderall XR will require additional clinical data for approval.

Shire CEO, Matthew Emmens stated, "Adderall XR is the most prescribed brand for the treatment of ADHD in the US, a market that expanded by 20 per cent over last year. The impact of ADHD on people's ability to carry out their daily lives and work effectively is being increasingly acknowledged and the market for adult patients could ultimately be double that for paediatric patients. Although we have not been able to promote adult usage, many physicians have been prescribing Adderall XR for adults 'off label' for some time. Adults represent 15 - 20 per cent of the current Adderall XR total prescriptions. We can now support the expansion of this adult market segment."

Studies have shown that up to 65 per cent of children with ADHD continue to exhibit symptoms into adulthood and an estimated 4.4 per cent of the US adult population is affected by ADHD. If left untreated, this disorder may lead to other psychological difficulties, such as depression, as well as occupational and social disability. Appropriate diagnosis and treatment of ADHD in adults helps improve self-esteem, work performance and skills, educational attainment and social competencies. Over 8 million adults in the US may exhibit the symptoms of ADHD, while only an estimated 600,000 are being treated.

Dr Richard H Weisler, adjunct Professor of Psychiatry at the University of North Carolina, Chapel Hill (UNC) School of Medicine and principal investigator for Adderall XR studies in adults, commented:

"ADHD in adult patients may significantly impair a person's social and family relationships, as well as his or her career. Stimulant therapies, such as Adderall XR, have been used successfully in patients for more than 60 years. It's an important step that Adderall XR is the first stimulant to be approved for use in adults."

The US FDA approved Adderall XR in November 2001 for the treatment of ADHD in children.

Adderall XR net sales for the 6 months to June 2004 were US $283 million, 30 per cent up on the same period in 2003. Shire will begin promoting the adult indication in the US immediately.