Noncredible symptom presentation in ADHD refers to invalid, exaggerated, or feigned self-report of inattention, hyperactivity, impulsivity, or functional impairment that is inconsistent with actual abilities.
It can involve conscious feigning of symptoms for secondary gain or unconscious exaggeration of difficulties due to psychiatric factors or misattribution of common problems to ADHD.
Lee, G. J., Do, C., & Suhr, J. (2023). Noncredible presentations of symptoms and functional impairment in the assessment of adult attention-deficit/hyperactivity disorder. Psychology & Neuroscience, 16(3), 284–301. https://doi.org/10.1037/pne0000319
Key Points
- The study examined the relationship between noncredible symptom presentation and self-reported symptoms, perceived functional impairment, and their relations to one another in 78 adults undergoing clinical evaluation for ADHD.
- Noncredible responders reported greater ADHD symptoms, psychological symptoms, and functional impairment compared to credible responders.
- Inattentive symptoms were most related to perceived functional impairment, even when controlling for noncredible presentations.
- The relationship of perceived functional impairment to symptoms of depression and anxiety varied depending on whether individuals responded credibly or noncredibly.
- The findings highlight the need for validity testing when assessing both symptoms and functional impairment in ADHD evaluations.
Rationale
Accurate assessment of both ADHD symptoms and associated functional impairment is critical not only for establishing a valid ADHD diagnosis, but also for informing treatment decisions.
However, there is limited understanding of how noncredible symptom presentation impacts self-report measures used in ADHD assessments.
Overreliance on subjective self-report data can increase the risk of response biases that lead to inaccurate conclusions (Musso & Gouvier, 2014).
While emerging research shows that self-report measures of ADHD symptoms and functional impairment ratings are vulnerable to noncredible responding in simulation studies (e.g., Walls et al., 2017), no study has examined this using formal classification criteria for noncredible presentation or investigated whether it affects the relationship between self-reported symptoms and functional impairment.
As such, this study aimed to classify adults undergoing ADHD evaluations as credible or noncredible responders using Sherman et al.’s (2020) criteria in order to examine group differences in self-reported ADHD symptoms, psychological symptoms, and functional impairment.
Additionally, this study tested whether noncredible presentation moderates the association of symptom severity to perceived functional impairment.
Method
- Adults presenting for ADHD evaluations were administered self-report measures of ADHD symptoms.
- Participants were classified as noncredible (n = 48) or credible (n = 30) responders using Sherman et al.’s (2020) criteria.
- The criteria for noncredible responders were those who scored in the invalid range on either symptom validity tests (the CAARS Infrequency Index or MMPI overreporting validity scales) or performance validity tests (Word Memory Test, Reliable Digit Span, Rey AVLT Recognition, or AVLT Exaggeration Index).
- Participants were classified as credible responders if they did not meet criteria for noncredible responding by passing symptom and performance validity tests.
Sample
- 78 adults presenting to an outpatient clinic for ADHD evaluations
- 53 females, 17 males, 8 nonbinary
- Mean age = 25 years
- Predominantly white sample (64 participants)
Statistical Analysis
- Differences between groups on self-report measures were analyzed using independent samples t-tests.
- The moderating effect of group classification was tested using Pearson correlations and linear regression models.
Results
As hypothesized, the noncredible group reported significantly greater symptoms than the credible group with large effect sizes, including:
- Inattentive symptoms: 84.19 vs 75.43, p = .003, d = .87
- Hyperactive-impulsive symptoms: 71.44 vs 59.73, p < .001, d = .91
- Total ADHD symptoms: 70.71 vs 62.90, p < .001, d = .92
The noncredible group also reported greater psychological symptoms than the credible group with large effect sizes, including:
- Demoralization: 69.21 vs 56.79, p < .001, d = 1.10
- Somatic complaints: 66.62 vs 53.17, p < .001, d = 1.24
- Low positive emotions: 65.50 vs 57.41, p = .004, d = .62
- Dysfunctional negative emotions: 67.44 vs 56.10, p < .001, d = .99
Additionally, the noncredible group reported significantly higher functional impairment than the credible group, with a large effect size (5.54 vs 3.58, p < .001, d = 1.37).
Insight
A key insight is that while ADHD symptoms and functional impairment are inherently related constructs, noncredible symptom presentation seems to weaken their association.
For credible responders, greater self-reported ADHD and psychological symptoms were moderately-to-strongly correlated with higher perceived functional impairment. However, most bivariate relationships between self-reported symptoms and perceived functional impairment were small and non-significant for noncredible responders.
Additionally, relationships between perceived functional impairment and symptoms specifically related to depression and anxiety were significant for credible responders but not for noncredible responders.
This pattern suggests that noncredible responders report elevated symptoms without necessarily linking them to impairment in major areas of life activities. In contrast, credible responders may be more likely to perceive their symptoms in the context of disruptions in their daily functioning.
By showing that noncredible presentation impacts subjective symptom report and its relationship to perceived functional impairment, this study underscores the need for multi-method assessment approaches.
Using both symptom and performance validity tests can improve the accuracy of symptom and impairment ratings and guard against response biases leading to inaccurate diagnostic decisions or treatment planning.
Strengths
The study had several methodological strengths:
- Use of a well-validated formal criteria for classifying noncredible presentation based on both presentation validity test (PVT) and symptom validity test (SVT) outcomes
- Inclusion of an ADHD-specific measure of functional impairment not previously examined in relation to noncredible symptom report
- Adequate sample size to detect large group differences
- Groups equivalent on demographic variables like age, education level, and race/ethnicity
- Examination of both ADHD and psychological symptoms in relation to functional impairment
- Multiple indices of symptoms (inattention, hyperactivity, anxiety, depression, somatization)
- Testing moderation effects of noncredible presentation on the relationship between self-reported symptoms and functional impairment
The standardization of symptoms scores and functional impairment ratings based on normative samples increased interpretability of the data.
Additionally, the study improved upon limitations of prior simulation-based studies by using a clinical sample of adults actually presenting for ADHD assessments rather than asking non-clinical participants to feign symptoms. This helped capture effects of noncredible responding as it occurs in real-world testing scenarios.
Limitations
However, the study had some limitations:
- Sample consisted mostly of White postsecondary students, limiting generalizability of findings to the broader population. Studies with larger, more diverse community samples would be informative.
- Most participants did not have a confirmed diagnosis of ADHD based on childhood history, current impairment, and other diagnostic measures. It is unclear if including more stringently diagnosed samples would produce different results.
- The statistical moderation findings require replication in future studies to determine the reliability of effects.
- Functional impairment ratings relied entirely on self-report. Multi-method assessments using informant reports and documentation of objective impairment are also warranted.
- The ADHD-specific impairment measure only included one question per domain. Examining specific areas of functional impairment in greater detail could provide more nuanced results.
- A small subset of “credible” responders failed one PVT but no SVT. It is possible some of these participants still had mild noncredible elements even though they were classified as responding validly based on the chosen research criteria.
Implications
This study makes a significant contribution by demonstrating functional impairment ratings are equally susceptible to over-reporting as ADHD symptom measures.
Additionally, it raises concerns about relying predominantly on patient self-report when assessing impairment, highlighting the need for multi-method evaluation approaches.
Clinicians are urged to consider both symptom and performance validity testing when diagnosing ADHD in adults to improve diagnostic accuracy and treatment planning.
The finding that symptoms of depression and anxiety were strongly tied to perceived impairment for credible but not noncredible responders also carries important clinical implications. It suggests that noncredible presentations may obscure the typical comorbidity between ADHD and internalizing disorders.
Failure to identify comorbid conditions could negatively impact prognosis if left untreated alongside ADHD interventions.
Additionally, the weakening of associations between self-reported symptoms and impairment among noncredible responders indicates that perception of disability serves an important validating role in the assessment of ADHD.
Clinicians should exercise skepticism if patients report significant ADHD symptoms without conveying associated life disruption. Future research can build upon these findings by developing and testing symptom validity tools specifically for common measures of ADHD-related impairment.
Broader implications pertain to the assessment of other mental health conditions, especially those relying heavily on self-report data. Similar patterns may emerge wherein noncredible responding artificially inflates perception of symptoms separate from functional disability.
As such, clinicians across disciplines should be cognizant of the potential disconnect between subjective symptom report and objectively measured dysfunction when evaluations risk biased responding.
References
Primary reference
Lee, G. J., Do, C., & Suhr, J. (2023). Noncredible presentations of symptoms and functional impairment in the assessment of adult attention-deficit/hyperactivity disorder. Psychology & Neuroscience, 16(3), 284–301. https://doi.org/10.1037/pne0000319
Other references
Musso, M. W., & Gouvier, W. D. (2014). “Why is this so hard?” A review of detection of malingered ADHD in college students. Journal of Attention Disorders, 18(3), 186–201. https://doi.org/10.1177/1087054712441970
Sherman, E. M. S., Slick, D. J., & Iverson, G. L. (2020). Multidimensional malingering criteria for neuropsychological assessment: A 20-year update of the malingered neuropsychological dysfunction criteria. Archives of Clinical Neuropsychology, 35(6), 735–764. https://doi.org/10.1093/arclin/acaa019
Walls, B. D., Wallace, E. R., Brothers, S. L., & Berry, D. T. R. (2017). Utility of the Conners’ Adult ADHD Rating Scale validity scales in identifying simulated attention-deficit hyperactivity disorder and random responding. Psychological Assessment, 29(12), 1437–1446. https://doi.org/10.1037/pas0000530
Keep Learning
Here are some thought-provoking discussion questions about this research a college class could explore:
- What ethical considerations should clinicians make when assessing for noncredible symptom presentation in vulnerable populations seeking mental health treatment?
- How might perceptions of ADHD symptoms versus associated life impairment vary across different ages, cultural groups, and socioeconomic backgrounds? What biases might clinicians hold about disability?
- Should academic/occupational policies regarding ADHD diagnoses and accommodations consider information beyond patient self-report? What methods could supplement self-report data?
- How might advances in neuroimaging and biomarker research improve future detection rates of noncredible ADHD presentations? What are limitations of relying on biological data?
- What responsibilities do clinicians have to educate patients about the concept of noncredible presentation? Should this information be incorporated into informed consent?
