Identifying ADHD in an Outpatient Substance Use Disorder Clinic
Introduction
Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by persistent patterns of inattention, hyperactivity, and impulsivity. Individuals with ADHD are at a higher risk of developing substance use disorders (SUDs), and a significant proportion of patients with SUDs also meet the criteria for ADHD. Identifying and treating ADHD in an outpatient SUD clinic is crucial for improving patient outcomes, including reduced substance use, improved adherence to treatment, and enhanced overall functioning.
Prevalence and Importance
High Comorbidity: Research has shown that ADHD has a prevalence of 2.5% in adults (Simon et al., 2009) and 3.4% in childhood (Polanczyk et al., 2014). Recent studies indicate that approximately 20–30% of adults with SUDs may have comorbid ADHD (Rohner et al., 2023).
Impact on Treatment Outcomes: Untreated ADHD can hinder the effectiveness of SUD interventions, leading to higher relapse rates and poorer psychosocial outcomes (Fluyau et al., 2021). One study showed that among patients in an addiction psychiatry clinic, only 5% of those receiving ADHD medication as part of their treatment dropped out within 90 days of admission, whereas 35% of patients not taking ADHD medication discontinued treatment by the 90-day mark (Kast et al., 2021). See figure below.
Early Identification: Prompt recognition and management of ADHD can improve engagement in SUD treatment programs and enhance recovery rates. A recent analysis of RCTs demonstrated that patients receiving stimulant medications experienced a range of beneficial effects compared to those given a placebo. These benefits included reduced substance use, increased abstinence rates, diminished cravings, improved management of withdrawal symptoms, and decreases in both the frequency and severity of ADHD symptoms (Fluyau et al., 2021)
Identifying ADHD in SUD Patients
Challenges in Diagnosis
Symptom Overlap: Symptoms of ADHD and substance use can overlap, making differential diagnosis challenging. Studies continue to show that both ADHD and SUD cause disruptions in various cognitive domains, including (Slobodin et al., 2020):
Planning: Organizing and sequencing actions to achieve goals.
Working Memory: Holding and manipulating information over short periods.
Decision-Making: Choosing between different actions or responses.
Inhibition Control: Suppressing inappropriate or unwanted behaviors.
Attention: Sustaining focus on specific tasks or stimuli.
Substance-Induced Symptoms: Acute or chronic substance use can mimic or mask ADHD symptoms. For example, the use of stimulants can lead to changes in attentional capacity and activity levels during both intoxication and withdrawal. Similarly, chronic marijuana use may result in attention deficits (Mariani & Levin, 2007).
Withdrawal Effects: Withdrawal from substances may temporarily exacerbate attentional and behavioral symptoms.
Screening Tools
Identifying ADHD in individuals with co-occurring SUD presents unique challenges due to overlapping symptoms and the influence of substances on cognitive and behavioral functions. Below is a discussion of the pros and cons of four commonly used ADHD screening tools when applied in this context.
Adult ADHD Self-Report Scale-Version 1.1 (ASRS-V1.1)
Pros:
Freely available for use and can be downloaded from reputable sources, including the WHO website.
Brief and Practical: Consists of 18 questions, with a short version of 6 items, making it suitable for quick screening in clinical settings.
Validated Tool: Developed in conjunction with the WHO and has strong psychometric properties.
High Sensitivity and Specificity: Effective in identifying ADHD symptoms in the general adult population.
Cons:
Self-Report Limitations: Accuracy may be compromised in individuals with SUD due to factors like cognitive deficits, denial, or manipulation.
Overlap with Substance Effects: Symptoms like inattention and restlessness can be caused by active substance use or withdrawal.
Does Not Confirm Diagnosis: As a screening tool, positive results require further evaluation for a definitive diagnosis.
Considerations in SUD Context:
Screening Tool, Not Diagnostic: Positive screens should prompt a more comprehensive assessment, ideally during a period of abstinence.
Adjunct to Clinical Judgment: Should be used alongside clinical interviews and collateral information for accurate diagnosis.
Wender Utah Rating Scale (WURS)
Pros:
Available for free and can be found in various academic publications and online resources.
Retrospective Focus on Childhood Symptoms: Specifically designed to assess childhood ADHD symptoms in adults, helping establish the onset before the age of 12 as required by DSM-5 criteria.
High Sensitivity: Effective in identifying individuals who may have had ADHD symptoms during childhood.
Cons:
Retrospective Recall Bias: Reliance on adult recollection of childhood behaviors can be problematic, especially in patients with SUD who may have memory impairments.
Limited Assessment of Current Symptoms: Does not evaluate current ADHD symptoms, necessitating additional tools for a complete assessment.
Less Specific in SUD Populations: May not adequately distinguish between ADHD and other psychiatric conditions or the effects of long-term substance use.
Considerations in SUD Context:
Use as Part of a Comprehensive Assessment: Should be combined with current symptom assessments and collateral information.
Potential for Inaccurate Recall: Memory distortions due to chronic substance use may affect the reliability of retrospective self-reports.
Diagnostic Interview for ADHD in Adults (DIVA-5)
Pros:
Can be downloaded for 10 euros from the DIVA Foundation's official website for non-commercial purposes.
Structured Diagnostic Tool: Based directly on DSM-5 criteria, covering both current and childhood symptoms thoroughly.
Includes Examples: Provides concrete examples for each symptom, aiding patient understanding and accurate reporting.
Assesses Impairment: Evaluates the impact of symptoms on various domains of functioning (e.g., work, relationships).
Cons:
Time-Intensive: Can take 60 to 90 minutes to administer, which may be challenging in certain clinical settings.
Requires Training: Effective use necessitates familiarity with the instrument and interviewing skills.
Patient Engagement: Length and depth of the interview may be taxing for patients with SUD, especially if they are experiencing withdrawal symptoms.
Considerations in SUD Context:
Optimal Timing: Best administered when the patient is sober and cognitively stable to ensure reliable responses.
Combines Multiple Sources: Encourages the use of collateral information to validate patient reports.
Differentiation of Symptoms: Aids in distinguishing between ADHD symptoms and those related to substance use or other psychiatric conditions.
Conners Adult ADHD Rating Scale (CAARS)
Pros:
Comprehensive Assessment: Offers both self-report and observer-rated forms, covering a wide range of ADHD symptoms including inattention, hyperactivity, impulsivity, and problems with self-concept.
Norm-Referenced Scores: Provides normative data, allowing clinicians to compare an individual's scores with those of a representative adult population.
Multiple Subscales: Includes subscales that can help differentiate between ADHD symptom clusters, which is valuable in tailoring interventions.
Cons:
Requires purchase
Time-Consuming: The full version can be lengthy to administer (42 to 66 items), which may be impractical in busy outpatient settings or for patients with limited attention spans.
Symptom Overlap with SUD: Many ADHD symptoms assessed (e.g., restlessness, impulsivity) can be mimicked by substance intoxication or withdrawal, potentially leading to false positives.
Self-Report Bias: Individuals with SUD may underreport or overreport symptoms due to cognitive impairments, denial, or secondary gain (e.g., seeking stimulant medications).
Considerations in SUD Context:
Interpretation Requires Caution: Clinicians need to carefully differentiate between symptoms arising from ADHD and those induced by substance use.
Supplement with Collateral Information: Gathering information from family members or significant others can enhance diagnostic accuracy.
Selecting the appropriate ADHD screening tool in the context of co-occurring substance use disorders depends on several factors, including the clinical setting, time constraints, and the patient's cognitive and emotional state. While tools like the ASRS-V1.1 offer practicality and ease of use, comprehensive instruments like the DIVA-5 provide a more detailed assessment but require more time and expertise. Clinicians should balance these factors and consider using a combination of tools to enhance diagnostic accuracy. Ultimately, a thorough and nuanced approach is essential to differentiate ADHD from substance-induced symptoms and to develop effective treatment plans.
DSM-5 Criteria for ADHD
ADHD is characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), outlines specific criteria for diagnosing ADHD, which are summarized below:
A. Core Symptoms
An individual must exhibit six or more symptoms from either (or both) of the following categories for at least six months. For adolescents aged 17 and older and adults, five or more symptoms are required.
1. Inattention
Careless Mistakes: Often overlooks details or makes errors in schoolwork, work, or other activities.
Difficulty Sustaining Attention: Frequently has trouble maintaining focus during tasks or play.
Seeming Not to Listen: Often appears not to listen when spoken to directly.
Failure to Follow Through: Does not complete instructions, chores, or duties in the workplace.
Organizational Problems: Struggles with organizing tasks and activities.
Avoidance of Sustained Effort: Reluctant to engage in tasks requiring prolonged mental effort.
Losing Necessary Items: Misplaces items like tools, wallets, keys, or documents needed for tasks.
Easily Distracted: Gets sidetracked by extraneous stimuli.
Forgetfulness: Often forgets daily activities like running errands or keeping appointments.
2. Hyperactivity and Impulsivity
Fidgeting: Frequently fidgets with hands or feet or squirms in seat.
Leaving Seat: Often gets up from seat when remaining seated is expected.
Inappropriate Running or Climbing: Feels restless in situations where being still is required.
Difficulty with Quiet Activities: Has trouble engaging in leisure activities quietly.
"On the Go": Acts as if driven by a motor; uncomfortable being still for extended periods.
Excessive Talking: Talks more than what is considered appropriate.
Blurting Out Answers: Answers questions before they have been fully asked.
Difficulty Waiting Turn: Has trouble waiting in lines or for their turn in activities.
Interrupting or Intruding: Frequently interrupts conversations or intrudes on others' activities.
B. Age of Onset
Early Presentation: Several symptoms were present before the age of 12.
C. Symptom Presence in Multiple Settings
Consistency Across Environments: Symptoms are evident in two or more settings, such as at home, school, work, or in social situations.
D. Functional Impact
Clear Evidence of Impairment: Symptoms interfere with or reduce the quality of social, academic, or occupational functioning.
E. Exclusion of Other Disorders
Not Better Explained by Other Conditions: The symptoms are not solely a manifestation of another mental disorder (e.g., mood disorders, anxiety disorders, personality disorders) and do not occur exclusively during the course of schizophrenia or another psychotic disorder.
Specifiers
Based on the predominant symptom presentation over the past six months:
Combined Presentation: Both inattention and hyperactivity-impulsivity criteria are met.
Predominantly Inattentive Presentation: Inattention criteria are met, but hyperactivity-impulsivity criteria are not fully met.
Predominantly Hyperactive-Impulsive Presentation: Hyperactivity-impulsivity criteria are met, but inattention criteria are not fully met.
Severity Levels
Mild: Few symptoms beyond the minimum required for diagnosis; minor impairments in functioning.
Moderate: Symptoms and functional impairment are between mild and severe.
Severe: Many symptoms beyond the minimum, or several symptoms are particularly severe; significant impairment in functioning.
Notes:
Many adults with ADHD were not diagnosed during childhood, and this underdiagnosis can be attributed to several factors. Historically, there was less awareness of ADHD, especially regarding its presentation in inattentive forms that are less disruptive and therefore less likely to be identified by parents and teachers. Girls are particularly underdiagnosed because they often exhibit fewer hyperactive symptoms compared to boys, leading to their struggles being overlooked. Additionally, diagnostic criteria have evolved, and increased recognition of ADHD in adults has resulted in more individuals being diagnosed later in life when they seek help for ongoing difficulties in work or personal life (Kooij et al., 2019).
Collateral Information: Gathering information from family members or significant others can enhance diagnostic accuracy, especially in determining whether ADHD symptoms were present before substance use began. Collateral reports provide objective evidence of early-onset symptoms of inattention, hyperactivity, and impulsivity, supporting accurate diagnosis. This is especially important when patients have impaired recall or may underreport symptoms (Kooij et al., 2019).
References:
Fluyau, D., Revadigar, N., & Pierre, C. G. (2021). Systematic review and meta-analysis: Treatment of substance use disorder in attention deficit hyperactivity disorder. The American Journal on Addictions, 30(2), 110–121.
Kast, K. A., Rao, V., & Wilens, T. E. (2021). Pharmacotherapy for attention-deficit/hyperactivity disorder and retention in outpatient substance use disorder treatment: A retrospective cohort study. The Journal of Clinical Psychiatry, 82(2), e20m13691.
Mariani, J. J., & Levin, F. R. (2007). Treatment strategies for co-occurring ADHD and substance use disorders. The American Journal on Addictions, 16(Suppl 1), 45–54.
Polanczyk, G. V., Willcutt, E. G., Salum, G. A., Kieling, C., & Rohde, L. A. (2014). ADHD prevalence estimates across three decades: An updated systematic review and meta-regression analysis. International Journal of Epidemiology, 43(2), 434–442.
Rohner, H., Gaspar, N., Philipsen, A., & Schulze, M. (2023). Prevalence of attention deficit hyperactivity disorder (ADHD) among substance use disorder (SUD) populations: Meta-analysis. International Journal of Environmental Research and Public Health, 20(2), 1275. https://doi.org/10.3390/ijerph20021275
Simon, V., Czobor, P., Bálint, S., Mészáros, A., & Bitter, I. (2009). Prevalence and correlates of adult attention-deficit hyperactivity disorder: Meta-analysis. The British Journal of Psychiatry, 194(3), 204–211.
Slobodin, O., Blankers, M., Kapitány-Fövény, M., Kaye, S., Berger, I., Johnson, B., ... & van de Glind, G. (2020). Differential diagnosis in patients with substance use disorder and/or attention-deficit/hyperactivity disorder using continuous performance test. European Addiction Research, 26(3), 151–162.
Disclaimer: This summary is intended for informational purposes only and should not be used for self-diagnosis or as a substitute for professional evaluation. If you suspect that you or someone else may have ADHD, please consult a qualified healthcare provider.