Attention deficit/hyperactivity disorder, commonly known as ADHD, is a persistent developmental condition affecting approximately 2-5% of people, characterised by a mix of inattentive, impulsive and hyperactive behavioural symptoms (American Psychiatric Association, 2013). While the precise mechanism of ADHD remains unknown, it demonstrates significant heritability (Faraone et al., 2000), and its diagnosis is a clinical one by a mental health professional.
In considering therapeutics, it is estimated up to 4% of the British adult population might benefit for treatment for ADHD (Faraone & Biedermann, 2005). Currently, medication targeting the neurochemistry of dopamine transmission alongside behavioural interventions are the mainstay of efficacious ADHD therapy.
There remains uncertainty over the long-term persistence of any beneficial therapeutic effects of behavioural interventions. This is often accompanied by an imprecise definition of what ‘behavioural intervention’ might mean for the patient – with modalities including cognitive behavioural therapy (the most common), as well as neurofeedback, psychoeducation and ADHD coaching. However, since there is mounting evidence that adult patients around the world, for instance in Ireland, struggle to access appropriate diagnosis and pharmacological ADHD treatments, it is important that the efficacy of a variety of behavioural interventions can be tested against controls. This is the aim of this timely systematic review by Scholz et al. (2020), which further considers the feasibility of delivering efficacious therapies with a range of settings and professionals.
This systematic review evaluated inclusion by the following criteria:
Any cohort studies with mean participant age of 18 years or older (to indicate ‘adult ADHD’), meeting the DSM-5 criteria of Attention Deficit/Hyperactivity Disorder, or ICD-10 F 90 (.0, .1, .8, .9) and F98.8 as diagnosed by a specialist neurologist, psychologist, psychotherapist or psychiatrist.
Studies evaluating a range of behavioural interventions were eligible for inclusion, such as:
- Neurofeedback (NF) self-regulation of brain-activity
- Cognitive training (CT) for broad cognitive ADHD deficits such as memory and attention
- A broad range of behavioural therapies from Cognitive or Dialectical (CBT/DBT) to lesser-known Mindfulness or Metacognitive (MBCT/MCT), acknowledging the use of ‘a mix of methods’ in clinical practice
- ADHD coaching for improvement of ‘executive function’ symptoms such as time-management and organisation – notably, not requiring a licensed psychotherapist or psychologist
- Psychoeducation (PE) promoting self-acceptance of symptoms and resolving of associated guilt – usually also a component of behavioural therapies.
Studies were only included if they specifically analysed effects on inattention symptoms, or where authors could be contacted up to three times to provide essential sub-scale data for the review, using the most-common self- or observer-rated scale (e.g. CAARS-inattention) where multiple were available.
Assessment of bias
The Cochrane manual for assessing bias risk, modified with attrition bias rules from Babic et al. (2018) was used to define remits for risk of bias based on dropout rates of 9.4% (low), 9.5% to 19.4% (unclear), and >19.5% (high); these remits were shifted up by 10% for each category, if an intention to treat analysis was carried out for a study.
Measuring effect of treatment and feasibility
RevMan5 was used to analyse every intervention type separately, identifying and separating inactive (treatment as usual or waitlist) and active (other support/intervention) control groups.
P-values of 0.05 were significant in between-group comparisons, and effect sizes were evaluated by standardised mean differences (SMD) of 0.20 (small), 0.50 (moderate) and 0.80 (large), with a random effects model.
Feasibility was evaluated by total / session intervention duration, number of sessions and session frequency, as well as interventional settings.
Studies and participants
19 studies from 10 countries were ultimately included in the review, including an average patient age range of 20.21 – 41.04 years, who had a considerable percentage of varied psychiatric comorbidity (as high as 72.5% in Bachmann et al. 2018).
There were no studies with a low bias rating across all domains. Selection bias was often unable to be ascertained as randomisation and allocation concealment were poorly described across studies. Performance bias was inevitably high across all studies as it is not possible to blind patient or physician in the psychotherapeutic setting.
One study (Youngs et al. 2017) was excluded from analysis, due to high attrition bias rates.
- Results varied between studies, yet overall behavioural therapy was demonstrated to be the only modality among those reviewed, to effectively reduce inattentive symptoms in adults with ADHD, when compared against inactive controls, i.e. treatment as usual or waitlist.
- There were no studies which demonstrated any superior effects of Neurofeedback, Cognitive training, and Psychoeducation interventions alone.
- No clinical studies were available to evaluate ADHD coaching.
- Short term interventions were similarly efficacious to more long-term interventions.
In conclusion, this review indicates that behavioural therapy – encompassing benefits of psychoeducation – has superior outcomes for the management of inattentive symptoms for adults with ADHD. No superior effects of Neurofeedback, Cognitive training or Psychoeducation on inattention are demonstrated in current literature. As no studies have applied the scientific method to evaluate the effects of ADHD coaching on inattention, outcomes in this area are inconclusive.
There is room for future investigation into whether interventions such as psychoeducation or ADHD coaching, which have loosely defined remits of practice and can often be delivered by parties other than licensed medical practitioners, can deliver tangible benefit for adults experiencing inattentive symptoms of ADHD. Additionally, it is important to evaluate the duration and timing of these interventions in patients’ lives, to make the best possible breakthrough and longstanding improvements to patients’ quality of life.
Strengths and limitations
The narrowing of focus to exclusively inattention symptoms is treated as “very strict” by the authors, suggesting further research is needed to evaluate the efficacy of one or more of these therapies, on the broader clinical picture of ADHD.
While this is certainly true, as broader research questions might enable them to include any research studies on the efficacy of ADHD coaching for adults, as well as CT and NF in alternative active/inactive control contexts – they are excellent at contextualising their data retrieved and any conclusions derived, against the wider picture of ADHD symptomatology consistently throughout the article. They highlight that patients experience “cognitive heterogeneity” and a “non-linear relationship to ADHD symptomatology”, which contextualises even a narrow research question well in a varied setting of clinical practice.
A notable limitation of outcome is that this granular systematic review was unable to establish that any single modality shows conclusive benefits against inactive and active control groups, in individual or group settings; and they did not configure the study to assess long-term follow-up outcomes. However, they acknowledge that modalities such as PE and CT may not show superiority in isolation, but educative or cognitive elements of these modalities over time may contribute to the superiority of behavioural therapies against inactive controls – hence clearer future research is needed to “assess single elements of behavioural therapy for adult ADHD”.
Implications for practice
Overall, the researchers remark:
Taken together, inattentive symptoms among adult patients with ADHD may be successfully treated with psychotherapeutic strategies, however specificity of the psychotherapeutic intervention might not be the crucial factor.
This paper specifically analyses and is more pertinent to adults with ADHD who primarily exhibit inattentive symptomatology. In this context the current evidence base indicates that active pharmaceutical intervention is still superior to most forms of psychotherapeutic engagement for this patient subset. However, behavioural interventions with elements of psychoeducation and cognitive self-regulation may provide an appealing therapeutic adjunct / alternative to waitlisting for patients struggling with inattention or disorganisation.
Particularly in resource poor / non-public healthcare systems like Ireland, where adult access to psychiatrists or pharmaceutical treatments are prohibitively expensive with long waiting lists, adults are forced to survive with a worse quality of life until such a time they can approach the diagnostic process. They may also be diagnostically disadvantaged, if they are additionally from a minority ethnicity or other minoritised social group. For this group, if behavioural therapies are employed by psychiatrist or coaches with adequate additional training in cultural sensitivity, they may provide a more accessible and affordable route to symptom management and a better quality of life as an interim or indeed long-term solution.
Statement of interests
There are no conflicts of interest for the author, in writing this article.
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