Assessment
This guideline provides an overview of the recommended Adult ADHD assessment steps, differentials to be considered and options for treatment according to the best available evidence based guidelines.
Medical, laboratory and other special examinations
Recognition of adult ADHD as a chronic disorder which needs chronic treatment is crucial. ADHD is a clinical diagnosis, which should only be made by a specialist psychiatrist, paediatrician or other healthcare professional with training and expertise in the diagnosis of ADHD. Adults with suspected ADHD whom have previously been diagnosed with ADHD during childhood with symptoms suggestive to ongoing ADHD can consult general adult psychiatric service for confirmation of diagnosis and ongoing treatment. Adults with suspected ADHD without previous diagnosis during childhood should be assessed by a specialist psychiatrist with adequate training and experience in assessments of adults with suspected ADHD for confirmation of diagnosis and treatment initiation.37
It is important to consider the history of presenting complaints, but also to use (semi-)structured interviews, rating scales, school- or work-related assessments, social functioning assessments and collateral information in the diagnosis of the disorder.
Screening
Commonly used rating scales for screening adult ADHD include the World Health Organisation Adult ADHD SelfReport Scale (ASRS) Symptom Checklist,38 the Barkley adult ADHD rating scale,39 the Brown ADD Scale Diagnostic Form (BADDS),40 the ADHD Rating Scale,41 the Conner’s Adult ADHD Rating Scale (CAARS) (DSM–IV),42 the Wender Utah Rating Scale (WURS),43 and the Wender-Reimherr Adult Attention Deficit Disorder Scale.44 The WHO ASRS is the best researched, and the shortened 6-item version has a sensitivity of 68.7% and specificity of 99.5% with total classification accuracy of 97.9% evaluated using population survey data. However, specificity of this and other screening tools may be lower within clinical samples with high rates of other mental health disorders, and positive screens should always be followed by full diagnostic evaluations based on clinical interview data.
Clinical Evaluation
The clinical interview is one of the cornerstones of the assessment process in diagnosing adult ADHD. Although various standardised, structured interviews and rating scales are available, these cannot replace the clinical assessment, but can add some rigor, standardisation and a quantifiable dimension to the areas being evaluated.
For the main diagnostic assessment, the use of the following structured diagnostic interviews may be considered: the Brown Adult ADHD Diagnostic Interview,40 the Conners Adults ADHD Diagnostic Interview for DSM-IV (CAADID),45 or the Diagnostic Interview for ADHD in adults (DIVA).46
A thorough interview is needed, documenting present symptoms and functionality across all spheres of the patient’s life. An assessment of the following would be essential: exploring the presence of the core symptoms of ADHD (inattention, hyperactivity and impulsivity), establishing the pervasiveness thereof throughout the individual’s lifespan and across different settings (work, school and social domains) and the presence of significant functional impairment throughout the lifespan and across different settings. It has to be noted that the expression of ADHD in adults differs to some extent from that in children, and the diagnostic descriptions of some of the features need to be adapted to adult expression of the disorder (physical over-activity in childhood could be replaced in adulthood by constant mental activity, feelings of restlessness and difficulty engaging in sedentary activities). The Barkley Functional Impairment Scale for adults39 and the Weiss Functional Impairment Rating Scales (WFIRS)47 are useful measures to assess the impact of symptoms on clinically relevant domains of functioning.
Differential diagnoses (e.g. a lack of effort, poor vocational match, or transient situational or environmental circumstances) and other psychiatric or medical diagnosis (and treatment thereof) that can explain the symptoms should be excluded. Furthermore, a thorough evaluation for the presence of comorbid psychiatric disorders (including substance use) is essential.
Comorbidity in individuals with adult ADHD is very common. Comorbid disorders can be the presenting problem in many adults and is a confounding factor in the diagnosis of ADHD, with a negative impact on treatment decisions and response. International studies indicated that the majority of adults with ADHD have complicating and clinically significant comorbid psychopathology, with more than one psychiatric disorder in up to 87%, whereas at least 57% of individuals have more than two psychiatric disorders.
In a South African database analysis,19 psychiatric comorbidity was also more prevalent in individuals with adult ADHD than in the general population for both anxiety disorders (13.1% vs. 8.1%) and mood disorders (13.8% vs. 4.5%). The presence of adult ADHD also more than tripled the prevalence of multiple comorbidity (9.09% vs. 3.9%). The most common psychiatric comorbidities were adjustment disorders in 29.5% of patients with comorbid psychiatric conditions (2.7% of the sample), followed by non-organic sleep disorders in 19.4% (1.8% of the sample) and anxiety disorders in 13.1% (1.2% of the sample). Mood disorders occurred as comorbid disorders in 13.8% of the patients (1.2% of the sample), whereas substance-related disorders occurred in 2.3% of adults with ADHD (0.2% of the sample).
In clinical psychiatric practice settings,19 psychiatrists indicated the presence of comorbid disorders in patients with adult ADHD as follows: anxiety disorders in 40.33% (the most prevalent being generalised anxiety disorder), SUD in 33.81% (with alcohol abuse being the most common substance of choice), major depressive disorder in 33.28% and bipolar mood disorder in 13.75%. Personality disorders as a group (mostly cluster B) were present in 28.26% of patients with adult ADHD.
Although a diagnosis based only on self-report is possible, such an approach may lead to an under- or over-diagnosis of ADHD, and it may be more reliable to obtain collateral information from other sources. Whenever possible, corroborating information should be obtained from a living parent, or older relative for childhood behaviour and a partner, relative or close friend for current behaviour and symptoms. This should include additional information on developmental and family history. Although Breda et al.48 found that collateral report has no incremental value in the evaluation of childhood ADHD symptoms in adults with a self-reported history of ADHD assessed in clinical settings, obtaining collateral information from parents on childhood ratings protect against possible student and adult malingering to obtain ADHD medications or accommodations.49
Medical, Laboratory and Other Special Examinations
It is important that each patient should have a thorough medical evaluation which would include a complete medical history and comprehensive physical examination with the purpose of excluding causative or comorbid medical disorders, and a baseline safety assessment. The minimum requirements are the documentation of vital signs, weight and height. Screening for visual and auditory deficits or processing and integration problems should be considered and appropriate referrals to specialist optometrists and speech and language pathologist considered. Special examinations are a significant cost-driver in the management of ADHD and should not be requested routinely. ECGs should be requested in any patient with personal or familial cardiac risk factors. Liver function tests should be requested in patients with a history of liver disease prior to initiating treatment with atomoxetine. A comprehensive neurological examination should be considered if any symptoms suspicious of neurological disorders, including head injuries or symptoms of epilepsy, are present, with an appropriate referral to a neurologist or for an EEG where indicated. There are at present insufficient data for the use of brain imaging modalities in the diagnosis of adult ADHD. Although the US Food and Drug Administration (FDA) has approved an electroencephalogram-based instrument as a diagnostic aid, demonstrating higher resting theta:beta waves, for ADHD in children (as part of a complete medical and psychological evaluation), there is currently no evidence for the use thereof in the diagnosis of adults with ADHD.50 Brain mapping, event-related potentials and neuroimaging are also of limited clinical use. It lacks diagnostic specificity, is costly and is not readily available.
Psychometric Evaluation
There are currently no neuropsychological tests for ADHD with sufficient sensitivity and specificity to serve as an individual diagnostic test.51,52,53 Although specific neuropsychological tests, especially those examining executive dysfunction, can be useful, it should not be used in isolation as a diagnostic tool in the absence of a comprehensive clinical evaluation by an experienced clinician, but as complementary to diagnostic assessments in order to determine individual deficits and to suggest individualised interventions.54 Current neuropsychological tests based solely on executive function are of limited value, whereas multi-domain assessments and computerised assessments (the Quantified Behavioural Test QbTest),55 the MOXO d-CPT,56 and the Test of Variable of Attention (TOVA)57 have not yet established utility and cost-effectiveness.
Neuropsychological assessments should be considered when the functional impairment the patient is experiencing is more than what would be expected from the core symptoms alone. Neuropsychological testing is also useful to supplement core treatment in the development of personalised treatment approaches and interventions for educational or work purposes, as well as monitoring treatment response and identifying areas which may need further interventions, but should not be used to establish treatment response.50
Sensitive use of general intelligence tests can be useful to ascertain potential attainment and to diagnose co-morbid learning disabilities for educational interventions.53 Appropriate referral to an educational psychologist should be considered.
Interest, reward and educational achievement are important complicating factors during the assessment of ADHD. A significant percentage of those making suspect effort during neuropsychological evaluation will be diagnosed with ADHD using the most commonly employed assessment methods: interview alone (71%), interview and behaviour rating scales combined (65%) and an interview, behaviour rating scale and Continuous Performance Test (CPT) test combined (57%). It is therefore essential to evaluate task engagement and possible symptoms amplification during clinical evaluation.58
Click here for the ADHD Treatment Armamentarium in South Africa
Schoeman R, Liebenberg R. The South African Society of Psychiatrists/Psychiatry Management Group Management Guidelines for Adult Attention-Deficit/ Hyperactivity Disorder. S Afr J Psychiat. 2017;23(0), a1060. https://doi.org/10.4102/sajpsychiatry.v23i0.1060 - An Update on the ADHD Treatment Armamentarium in South Africa., Prof Renata Schoeman
South African Journal of Psychiatry; The South African Society of Psychiatrists/Psychiatry Management Group the Management Guidelines for Adult Attention-Deficit/ Hyperactivity Disorder, 28 April 2017_An Update on the ADHD Treatment Armamentarium in South Africa, 2023