THE number of patients in Scotland being prescribed drugs for Attention Deficit Hyperactivity Disorder (ADHD) has reached a new high of more than 12,000.

The majority of patients are boys aged between 10 and 14. The condition refers to a range of behavioural problems associated with a poor attention span, such as poor concentration, restlessness and hyperactivity, that can obstruct their ability to learn and socialise.

The majority of ADHD patients are not on drug treatments. However, the latest data from ISD Scotland shows that the total number of ADHD patients receiving medicines for the condition in 2016/17 was 12,145, up 81 per cent from 6,711 in 2009/10.

The statistics also show that there was a 119 per cent increase in the number of ADHD prescription items dispensed in the past 10 years. However, only three health boards - NHS Borders, Fife and Tayside - have substantially higher rates of ADHD drug dispensing than the Scottish average.

The cost of to the NHS of prescribing ADHD drugs is now £6.4 million a year, compared to £2.5m in 2006/7.

The data comes amid an ongoing debate, highlighted by the Herald's 'Bitter Pill' series, over ADHD. While some professionals argue that the condition is being over-diagnosed and children needlessly medicated, other psychiatrists - as well as patients and their families - insist that drugs such as Ritalin have had a major positive affect on their ability to function.

Meanwhile, the latest batch of figures on mental health prescribing also highlight an increase in prescriptions for antidepressants, antipsychotics and dementia.

The number of patients in Scotland being prescribed at least one antidepressant reached a new high of 877,453 in 2016/17. However, patients can be prescribed antidepressants for conditions other than depression, such as neuropathic pain, post-traumatic stress disorder and anxiety disorders. The total number of antidepressant prescription items dispensed rose 75 per cent in the decade, but the costs have remained almost unchanged - at £44.6m last year - on account of falling prices.