The rise and fall of ADHD child prescribing in Western Australia: Lessons and implications

From 1989 to 2000 the number of Western Australians prescribed stimulant medication grew twenty-threefold. By 2000 there were 20,648 Western Australians on prescription stimulants. The Western Australia (WA) Health Department estimated 85% to 90% (17,551 to 18,583) were children. This represented 4.2% to 4.5% of all WA children aged between 4–17 years (Department of Health, 2002).

All through this period WA was the highest per capita prescribing Australian state or territory and in 2000 exceeded the USA national rate (Berbatis et al., 2002). By 2003 the number of Pharmaceutical Benefits Scheme (PBS) per capita Attention Deficit Hyperactivity Disorder (ADHD) prescriptions in WA was approximately three and a half times the Australian average (Whitely, 2010). There is limited data available, however, it appears the disproportionate rates were due both to higher per capita patient rates and higher than average doses.

In August 2003, prescribing accountability measures were tightened and subsequently there was a massive downturn in WA child prescribing rates. By 2005, only 8,057 children were on stimulants (Department of Health, 2006). Child prescribing rates continued to fall and in 2010 only 5,741 children were prescribed all forms of ADHD medications (Whitely, 2010b).

Even if in 2000 the WA Health Department estimate of children as a 85-90% proportion (based on ADHD prescription cohort in New South Wales) of the ADHD cohort was an overestimate, and the proportion of children in the ADHD cohort was only 70% (14,597), this still indicates a fall in the number of WA children prescribed ADHD ‘medications’ of over 60% between 2000 and 2010. Over a similar time period (2002–08) there was a 51% decline in teenage amphetamine abuse rates (Griffiths et al., 2008).

1989-2003: Perth’s child ADHD epidemic

Concerns about WA prescribing practices first emerged in the mid-1990s. In response the Court Liberal state government set up the Technical Working Party on Attention Deficit Disorder. The 1997 Report of the Technical Working Party highlighted concerns with the diagnostic practices of some unnamed Perth paediatricians and also identified two ADHD hotspots; one in Perth’s affluent western suburbs and the other in Perth’s economically disadvantaged south-east corridor. It concluded this patchy geographical distribution was probably ‘more reflective of the prescribing patterns of paediatricians servicing the various areas than it is of social or other factors’ (The Report of the Technical Working Party, 1997: p6). To address this inconsistency in prescribing rates it recommended ‘random audits into the use of block authorisations, and that paediatricians and psychiatrists found to be failing to abide by the appropriate criteria have their block authorisation capacity removed’ (The Report of the Technical Working Party, 1997: p20).

In WA only psychiatrists and paediatricians could (and can) initiate treatment with psycho-stimulants. Those who prescribed infrequently, as a last resort, were required to obtain approval for stimulant prescriptions written for each patient. ‘Block authorisation’ granted an exemption from these patient-by-patient prescribing accountability requirements to frequently prescribing psychiatrists and paediatricians considered to be ‘familiar with the prescribing guidelines’ (The Report of the Technical Working Party, 1997: p20). In effect, it meant that heavy prescribers were the least accountable. This seems completely irrational – why wouldn’t the heaviest prescribers have been the most accountable?

Despite the Working Party recommendations the audits never occurred and block authorisation was left unchanged. However, in 1997 the WA Department of Health established the WA Stimulants Committee. The Stimulants Committee was supposed to monitor the prescription of psycho-stimulants to ensure appropriate prescribing. The Committee gave the appearance of requiring accountability of prescribers, however, it included some of Perth’s heaviest prescribers, who had block authorisation, and were therefore exempt from oversight. Stimulants Committee minutes revealed that the committee took no action against illegal prescribers and a softly- softly approach to the most reckless prescribers, even when off label prescribing resulted in children being hospitalised (Whitely, 2010a).

August 2003 turning point: the abolition of block authorisation

In 2001 I was elected, as the Member for Roleystone, as part of the new Gallop Labor government. I raised the issue of block authorisation in my inaugural speech stating, ‘I believe making doctors accountable on a case-by-case basis for the prescription of stimulant medication is essential to dealing with the problem of over-prescription’ (Whitely, 2001). The change of government and the appointment of the Honourable Bob Kucera as Health Minister provided the opportunity for the direction of policy to be reversed. Minister Kucera, a former senior policeman, having seen the problems caused by the diversion of prescription dexamphetamine, was sympathetic to my arguments.

In 2002, the report Attentional Problems in Children and Young People was published by the Western Australian Mental Health Division (Department of Health, 2002). An earlier draft of the report proposed a tiered approach, with teachers and childcare workers spotting potential ADHD children and referring them up the chain for diagnosis by specialist clinicians. The draft report was, as a result of Minister Kucera’s and my input, significantly altered. The final report abandoned the ‘tiered spotters’ approach and recommended the abolition of block authorisation.

Despite fervent criticism from the then WA President of the AMA, Minister Kucera announced the decision to end block authorisation in December 2002 and the practice was stopped in August 2003 (James, 2002). The Stimulants Committee was replaced by the Stimulants Panel which had a significantly different membership and every prescriber was compelled to ‘apply to the (WA) Department of Health and obtain a unique Stimulant Prescriber Number to initiate stimulant treatment in any patient’. (Education and Health Standing Committee, 2004: p27). The abolition of block authorisation was followed by a massive (60-70%) decrease in the number of WA children on ADHD drugs. Perth is the world’s only ADHD hot spot to have seen such a dramatic downturn in prescribing rates for children.

While since 2003 prescriptions rates for WA children have plummeted, they have skyrocketed in all other Australian states. Although WA still has the highest (and rising) adult prescribing rates in Australia, in 2010 WA ADHD child prescribing rates were 4% below the national average. Perth has forfeited its claim to be the ADHD child prescribing capital of Australia. Sydney, Brisbane and Hobart now vie for that dubious honour (Whitely, 2010b).

Drug abuse and ADHD prescribing

Throughout the 1990’s and early 2000’s there was considerable anecdotal evidence of the diversion of ADHD amphetamines amongst WA teenagers and young adults. When data became available through the 2005 Australian Secondary Students’ Alcohol and Drug Survey (ASSAD) these suspicions were confirmed. Even though prescription rates had begun to drop by 2005 the ASSAD survey estimated that 9,492 (5.5%) of WA secondary school students had abused prescription ADHD amphetamines in the last year.

The same survey found that amongst 12-17 year-olds, 84% of those who had abused amphetamines in the last year had abused diverted stimulants, and that 27% of those who had been prescribed stimulant medication either gave it away or sold it. It also showed that 45% of WA high school students who had ever taken dexamphetamine or methylphenidate were not prescribed the drugs by a doctor (Drug and Alcohol Office, 2007).

In addition, ASSAD surveys indicated a reduction in ‘last 12 month amphetamine abuse’ by 12-17 year-olds from 10.3% in 2002 to 6.5% in 2005 (Griffiths et al., 2009). This 38% reduction occurred over a similar time period as the 50-60% fall in ADHD child stimulant prescribing rates. And between 2005 and 2008 as prescribing rates continued to fall so did teenage amphetamine abuse rates. In total between 2002 and 2008 there was a massive 51% decline in teenage (last 12 months) amphetamine abuse rates (Griffiths et al., 2009).

Far from supporting the commonly made assertion that medicating for ADHD prevents illicit drug abuse by self-medicating untreated ADHD sufferers, the WA experience is that there is a positive correlation between amphetamine abuse rates and the legal prescribing rates for amphetamines for the treatment of ADHD. This supports the common sense proposition that prescribing amphetamines facilitates the abuse of amphetamines. This view was accepted by the Western Australian Government with the then Premier Alan Carpenter telling the WA Parliament on 27 September 2007 ‘The evidence shows that if amphetamine prescribing rates are decreased, abuse rates are decreased.’ (Government of Western Australia, 2007).

WA study provides unique long-term data on the safety and efficacy of stimulants

The start of WA’s child ADHD epidemic coincided with the commencement of the Raine Study; a longitudinal, large-scale, generalised study of WA children’s health and wellbeing conducted in Perth. The ongoing Raine Study began in 1989 following a pregnancy cohort of 2868 women. Data was collected from the mother pre-birth and then her child at regular intervals (Telethon Institute for Child Health Research, 2011).

As was typical for Perth children born in 1989, a significant number of Raine Study children were later diagnosed ADHD. The data collected about the Raine Study ADHD cohort unintentionally provided a unique opportunity to review the long term effects of stimulants on children (Department of Health, 2010a). In 2010 this data was analysed to evaluate the long term safety and efficacy of ADHD stimulants.

By age fourteen ‘of the 1785 adolescents (remaining) in the study, 131 (7.3%) had received a diagnosis of ADHD’. At age five none of the 131 had taken ADHD stimulants. By age 14, 29 had never taken stimulants, 41 had been on prescription stimulants in the past but were not taking them, and 61 were on ADHD stimulants. This gave three groups for comparison, the ‘never medicated’, ‘previously medicated’ and the ‘currently medicated’ groups. In addition analysis of the effect of the duration of stimulant treatment was undertaken.

The review of the data was published in February 2010. The two most significant findings of the Raine Study ADHD Review were:

1. Long-term cardiovascular damage: ‘Compared to not receiving medication, the consistent use of stimulant medication was associated with a significantly higher diastolic blood pressure (of over 10mmHg). This effect did not appear to be solely attributable to any short-term effects of stimulant medication, as when comparing groups who were currently receiving medication, it was found that those who had consistently received medication at all time points had a significantly higher mean diastolic blood pressure than those who had not consistently received medication in the past (difference of 7mmHg). These findings indicate there may be a lasting longer term effect of stimulant medication on diastolic blood pressure above and beyond the immediate short-term side effects’ (Department of Health, 2010a: p52).

2. School failure: ‘In children with ADHD, ever receiving stimulant medication was found to increase the odds of being identified as performing below age-level by a classroom teacher by a factor of 10.5 times’ (Department of Health, 2010a: p6).

In addition the report indicated that there was a marginally negative outcome for both ADHD symptoms (inattention and hyperactivity) and depression with the long-term use of stimulant medication (Department of Health, 2010a).

The finding that amphetamine use may permanently raise diastolic blood pressure is of great significance. It had been previously recognised that while stimulants were in the patient’s system, heart rate and blood pressure were elevated, leading to the associated risks of heart attacks and strokes. But it was assumed that when the short-term stimulant effects wore off the cardiovascular system returned to normal.

However, the most startling finding was that past stimulant use increased the probability of an ADHD child falling behind at school by a massive 950%. This finding completely undermines the hypothetical ‘educational benefits’ basis of medicating for ADHD.

Initially, pro-medication proponents on the committee that commissioned the report claimed that the outcomes for the medicated ADHD children were most probably worse than those for un-medicated ADHD children because they had more ‘severe ADHD’. However, an analysis of the children’s data at age five established that there were no statistically significant differences in developmental, behavioural and health measures before the children were medicated (Department of Health, 2010a: p21).

As with all studies there are limitations with this study. While the sample size (131) was small; ‘it was larger than those in many short-term studies that supported the use of stimulants as a safe and effective treatment for children with ADHD’ (Department of Health, 2010b). Although the evidence now available from the Raine Study data review does not prove that amphetamines cause failure at school and permanent cardiovascular damage, it is compelling real world data free of design bias.

Conclusions and implications

WA’s history as the world’s first ADHD hot spot to see a massive decline in child prescribing rates offers valuable insights into the consequences of diagnosing and prescribing for ADHD.

The imposition of tighter accountability measures and changes in the panel oversighting ADHD prescription approvals in 2003 was followed by a 60-70% decline in ADHD child prescribing and a 50%+ fall in teenage amphetamine abuse rates. In addition the unique data from the Raine Study indicates children diagnosed ADHD who are treated with stimulants may be at significantly higher risk of permanent adverse cardiovascular and poor educational outcomes than never medicated ADHD diagnosed children.

In conclusion, WA’s unique experience indicates that in the absence of effective external controls, enthusiastic prescribers may create a child ADHD epidemic which facilitates the widespread abuse of prescription amphetamines and exposes children to the risk of permanent cardiovascular damage and academic failure.