A significant number of adults with unresolved depression, anxiety or addiction may actually have Attention Deficit Hyperactivity Disorder (ADHD), a condition that has been widely considered to resolve in late adolescence.

Armed with the correct diagnosis, adult ADHD sufferers could soon be prescribed Ritalin-style stimulant medications for a range of mental health problems that are not usually associated with the disorder, the Royal College of Psychiatrists’ annual meeting was told today (Friday 4 July).

Stimulant medication is currently only licensed for children with ADHD. However, the National Institute for Health and Clinical Excellence (NICE) is expected to recommend that this class of drug can be prescribed adults with ADHD in September 2008 – following the recognition that the condition persists into adulthood in about 20 per cent of cases diagnosed in childhood.

But while ADHD symptoms in children include inattentiveness, hyperactivity and impulsiveness, the condition in adults is associated with a much wider range of co-existing mental health problems.

Professor Phillip Asherson, professor of molecular psychiatry at the Institute of Psychiatry, told the meeting: “Most frequently, adults with ADHD are diagnosed with chronic and persistent depression and anxiety, difficult-to-treat alcohol and drug addiction and personality disorders.

“We don’t yet know whether these co-existing disorders are separate problems or whether these people are actually suffering from a form of ADHD that is presenting in a different way from the normal symptoms. It could be that many people are being diagnosed as having a separate disorder when in fact they have got ADHD.”

Currently, clinicians are wary of using stimulant medication in adults, as the only group of drugs that are licensed only for use in children. However, Professor Asherson said: “This is likely to change once the new NICE guidelines are launched in September.”

Meanwhile, Professor Asherson is about to embark on a major study to identify adults with ADHD who present in GP surgeries and addiction centres. “We have no idea as yet whether these problems will respond to stimulant medication. If they do, then this type of drug could provide effective treatment for a significant number of adults who currently have unresolved mental health problems,” he said.