Abstract
Introduction: build capacity first
In their article in this issue of the Australian & New Zealand Journal of Psychiatry, Young et al. make an aspirational call to address unmet need for attention deficit hyperactivity disorder (ADHD) assessment and treatment in people with a coexisting substance use disorder (SUD). They argue that ADHD can be reliably diagnosed during periods of active substance use, and that treatment of ADHD in this context improves outcomes.
In our response, we argue that active ADHD cannot be easily and reliably diagnosed among people with current SUD. Even if ADHD can be diagnosed and treated in this setting, the mental health and addiction sector cannot currently meet this need. The cart must not come before the horse: before creating an expectation that services should expand into this complex area, we need better evidence on the safety and efficacy of stimulant treatment in people with active SUD, clear local practice guidelines and a workforce that can meet the demand for treatment.
Diagnostic challenges
While estimates vary greatly, studies using structured self and informant ratings and appropriate diagnostic thresholds suggest at least 40–50% of people with childhood ADHD continue to be impaired by their symptoms as adults (Sibley et al., 2016). More awareness of these ongoing symptoms has led to a doubling in ADHD medication use in adults in Australia between 2007 and 2015 (Brett et al., 2017).
As Young et al. note, ADHD is very common in adults with SUD, and the two conditions tend to worsen each other. Other diagnoses including antisocial personality disorder (ASPD), anxiety disorders, and mood disorders are also common in both people with ADHD and those with SUD. All these conditions have symptoms which overlap with ADHD, increasing diagnostic challenges (see Table 1 for examples). Thus, while Young et al. advocate for routine ADHD screening, without comprehensive assessment of these comorbid conditions, screening will produce many false-positives – particularly since ADHD symptoms which start in adulthood are usually better explained by these comorbid conditions (Sibley et al., 2018).
Other clinical conditions which may mimic ADHD.
ADHD: attention deficit hyperactivity disorder.
Longitudinal data on employment, educational attainment, criminality and medical history should also be obtained. Incorporating validated self-report and collateral informant measures and formally assessing impairment is also a necessary part of a valid diagnostic assessment (Sibley et al., 2016). However, such comprehensive assessment is not only time-consuming and costly but also requires sophisticated clinical skills.
Treatment challenges
It is now accepted that stimulant therapy can help improve functioning for adults with ADHD. However, while Young et al. argue that treating ADHD in people with SUD is beneficial, there have been relatively few studies in this area. Furthermore, outcomes have been heterogeneous across studies and individual studies have had limitations including short follow-up durations, high dropout rates and the use of subjective outcome measures (Cook et al., 2017).
Many clinicians are reluctant to prescribe stimulants for ADHD symptoms in people with SUD due to the diagnostic challenges mentioned above, and concern about misuse or diversion for extramedical use. Detecting stimulant misuse or diversion in high-risk patients requires prescribers to see patients often, to develop a good alliance and to use urine drug testing judiciously. When these problems are suspected, collateral information gathering should be an ongoing process involving family members and other health professionals such as pharmacists. ADHD treatment therefore places a high demand on clinicians’ time. This is on top of the routine requirements for stimulant therapy which include physical monitoring, paperwork for treatment permits and adherence to controlled drug regulations.
The risk of misuse or diversion of prescribed stimulants can be reduced by using long-acting stimulant preparations (e.g. lisdexamfetamine or extended-release methylphenidate) or non-stimulant ADHD drugs such as atomoxetine. However, finding out whether misuse or diversion is occurring can be difficult. Despite this, many prescribers do not use strategies to detect these behaviours because either they think the strategies are ineffective or they lack the skills to use them (Colaneri et al., 2017). In this respect, we agree with the comments of Young et al. about the need to improve ADHD-specific knowledge and capability in the SUD treatment sector, and in particular knowledge about how to manage the risks just mentioned.
Achieving consistency in stimulant prescribing policies is also vital. This is particularly important when there are several clinicians seeing the same patient over time, for example, when patients enter prison or hospital care or move between regions. Major differences in prescribing practices are confusing and distressing for patients, and they can generate conflict between clinicians and complaints about care.
Workforce challenges and ethical issues
Young et al. argue for routine screening for ADHD to be implemented for adults with SUD. However, we believe this is not currently a realistic or ethical goal in places where public-sector mental health and addiction services are already struggling to keep up with demand. The lack of psychiatrists working in the addiction sector is also a major barrier to routine treatment of ADHD in people with SUD, and this problem is unlikely to be easily solved. An expectation that services should screen for ADHD would therefore have unintended consequences. This includes both failure to meet demand both for ADHD screening and treatment and, more importantly, demand for other types of healthcare. It may also lead to ADHD assessment and treatment being devolved to less qualified clinicians, meaning less careful patient selection, lower quality care and higher risk of inappropriate use of medications with likely harmful consequences.
The highest uptake of ADHD treatment is likely to be in the private sector, particularly in Australia where this sector is larger and more developed than New Zealand’s. However, more severe, complex or disadvantaged groups are less likely to be able to access private healthcare. Thus, a push to increase access to ADHD treatment for people with SUD is likely to increase inequality.
Solutions
Currently, the Royal Australian and New Zealand College of Psychiatrists endorses guidelines from the United Kingdom (see https://www.nice.org.uk) and Canada (see https://www.caddra.ca). However, there is a need for better local consensus on what the accepted standard of care is for people with coexisting ADHD/SUD before embarking on the type of broad case-finding strategy which Young et al. advocate. Consensus guidelines will need to be supported by high-quality randomized controlled trials on stimulant therapy in populations with other coexisting problems, including SUD, a history of stimulant misuse or diversion and ASPD. Local translational studies are also needed to ensure such evidence can be applied in the Australasian context.
If guidelines suggest these populations need better access to ADHD treatment, then this will require a highly trained and well-funded workforce to deliver on this expectation. In particular, more psychiatrists with specialized addiction training will be needed. Local consensus guidelines for Australia and New Zealand also need to address equity, to ensure that disadvantaged groups including women, people in prison and indigenous people have equal access to treatment.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
