One of the difficulties in psychiatry is that of threshold. When is something severe enough to require assessment, or intervention. Most guidelines suggest interventions should be step-wise, with medication considered after the use of talking therapy or behavioural treatment.

Another issue is recognition. There are patterns, that once described, are seen by clinicians. Often the original paper describes a group of people who did not quite fit into other classification systems, or are redefined as meeting these new criteria and not outmoded ones. The DSM, with its explicit criteria, freezes this process, which is fluid.

For there are risks: some disorders promulgated are false syndromes (such as ritual abuse, or multiple personality disorder). Others are real and no one who has seen the extreme end argues about that.

ADHD is an example of the latter. At the extreme end, no one would disagree that the child is disabled. But mild inattention, boredom and fidgiting? That was my primary and secondary schooling. I did not need things repeated overmuch: most of the time I heard them the first time and did not forget.

All stimulants — coffee included — do is make a touch slower. Useful in social situations.

The US influenced the UK somewhat, and then it is fairly clear that the UK clinicians agreed on a threshold for treatment, which is much higher than in the US, but lower than in France.

First, it is important to note that UK rates of ADHD drug prescribing in children are ?10 times lower than US rates (0.4% UK vs 4.4% in the USA in 2005),16 two to five times lower than Germany (0.49% in UK vs 2.21% in Germany in 2007 or 0.45% in UK vs0.9% in Germany in 2006)17 ,18 and more than four times lower than in the Netherlands (4.5 vs 19.5/1000 in 2006).6 However, UK rates are twice as high as in France (4.0 UK in our study vs 1.8/1000 children in 2005).19

Our analysis highlights two trends in UK ADHD drug prescribing in children. The first a strong increase after 1995, also observed in many other studies. Several studies reported a large increase between 1992 and 2008 in the prevalence of stimulant use in children under 18 in the UK. In the USA, the prevalence of ADHD drug use increased from 2.8% to 4.4% between 2000 and 2005. France also reported rising rates of methylphenidate use between 2003 and 2005 with lower absolute prevalence than in the UK at 1.8/1000 children in 2005. In Germany, a 45% increase in prevalence of ADHD drugs in children under 18?years was observed between 2000 and 2007.Finally, a sevenfold increase of the use of stimulants was observed in the Netherlands between 1996 and 2006.

Our study shows a clear break in the increasing trend of ADHD drug prescribing in children from 2007. Unfortunately, only few studies report rates of ADHD medication prescribing worldwide in children later than 2006. However, although an 1.84-fold increase in ADHD drug prescription was observed between 1995–1996 and 2003–2004 in the USA, the absolute rate of ADHD prescriptions changed little between 2002 and 2010 and the rate of methylphenidate use had no significant change between 2002 and 2010. In addition, a study investigating ADHD medication use in children in the US MEPS (medical expenditure’s panel survey) shows a relatively stable rate with 3.43% of ADHD medication use in children in 2004 and 3.45% in 2008. In Germany, a recent study shows the rate of ADHD drug prescribing in children in DDD (defined daily doses) between 1990 and 2010 using large insurance company data. They showed a slight change in the curve from 2008 although accurate numbers are not reported. As expected, the prevalence and incidence of diagnosed ADHD in the UK seems to follow a similar pattern from 2007. Stable or decreasing trends in ADHD diagnosis were also reported in Denmark and Germany.

Yes, this is drug data.

Yes, there is a place for methylphenidate. But the prescription of methylpheidate for ADHD is not something you should do urgently. One should assess: one should measure. And one should warn. These medications have side effects: cardiovascular risks, stunted growth, and being a target for theft. For the same basic molecule has a considerable street value.