Adults diagnosed with attention deficit hyperactivity disorder (ADHD) claim their symptoms affect their ability to perform at work, a new survey shows.

Conducted by McNeil Pediatrics in the United States, the research reveals that ADHD is a "relatively common" condition among adults of working age.

Some 56 per cent of those questioned said their disorder strongly affects their ability to succeed in the workplace.

Almost three quarters said they have trouble concentrating at work, while 61 per cent said they find it difficult to wrap up projects and 60 per cent said they find it hard to sit still in meetings.

Furthermore, half of those polled said they believe their ADHD negatively affects their chances of progression and promotion.

Only a small number of those known to have the disorder are being treated for it, the survey shows, even though medication can help to ease symptoms.

According to NHS Direct, while people with ADHD tend to suffer problems such as learning difficulties, the condition has no impact on intelligence.