Harald Merckelbach

Validity tests are widely used to detect distorted symptom presentation but offer little guidance on why such distortions occur. In an explorative qualitative study, we examined how forensic inpatients (n = 36) described antecedents of their response patterns during a collaborative feedback interview. Patients were classified as inattentive responders (n = 8), overreporters (n = 7), underreporters (n = 14), or comparison patients (n = 7) based on stand-alone validity measures administered during routine assessment. Transcripts were primarily coded on 11 literature-derived antecedent themes. Inattentive responders emphasized comprehension/scale-use problems, attention lapses, and disengagement. Overreporters described emotion-processing difficulties, needs for social attention, external incentives, and comprehension issues. Underreporters referred to self-presentational concerns, stigma, reactance-related disengagement, forensic stakes, autonomy/control motives, and mistrust/fear of disclosure. Accounts often highlighted modifiable treatment targets (e.g., interoception, stigma, mistrust, reactance). Overall, collaborative discussion of poor validity may inform case formulation and treatment planning in high-stakes forensic settings.

Symptom overreporting is often considered to be moderated by external incentives, such as financial or legal advantages, although other factors may also play a role. Preliminary studies have suggested a connection between symptom overreporting and alexithymia, that is, trait-like difficulties in recognizing and describing internal sensations. This study aimed to further clarify the relationships among external gain expectations, alexithymia, and symptom overreporting. Specifically, we examined whether alexithymia is related to overreporting in patients without self-reported external gain expectations. Using a cross-sectional design, patients referred for psychological assessments in a hospital setting completed a questionnaire about external gain expectations (e.g., regarding work, housing, legal issues). We differentiated between those with self-reports of external gain expectations (n = 73) and those without (n = 84). Both subsamples were administered the Toronto Alexithymia Scale-20 (TAS-20), the Structured Inventory of Malingered Symptomatology (SIMS), and the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF). Across the full sample, alexithymia showed a positive and statistically significant association with symptom overreporting on the SIMS and the Infrequent somatic responses scale (Fs) of the MMPI-2-RF: r = 0.44 and r = 0.31, respectively. These positive associations were also evident in the subgroup without self-reported external gain expectations (i.e., r = 0.35, 95% CI [0.14, 0.52] and r = 0.35, 95% CI [0.15, 0.53], respectively). Regression analysis indicated that self-reported external gain expectations did not account for the relationship between symptom overreporting and alexithymia. These findings suggest that alexithymia is associated with symptom overreporting independently of self-reported external gain expectations. More broadly, the results raise the possibility that alexithymic traits may compromise the accuracy of symptom reporting itself. If so, this has implications not only for the interpretation of symptom validity tests, but also for the broader use of self-report measures in clinical assessment.

Leonhard and Leonhard (2025) argue that Symptom Validity Tests (SVTs) and Performance Validity Tests (PVTs) constitute a form of junk science. This qualification stands in sharp contrast to the breadth and depth of the scientific work on validity tests. Leonhard and Leonhard treat these tests as if they were equivalent to polygraph evidence, a move that betrays a fundamental misunderstanding of the conceptual and empirical foundations of these instruments. More than a year ago, we invited Leonhard and Leonhard to provide case law examples —if only a few— demonstrating that SVTs and/or PVTs contributed to risky legal decisions. So far, they have not been willing or able to cite a single instance. We therefore reiterate our invitation: show us the cases.

Steven J. Lynn (1946–2024) was a prolific researcher who explored a wide array of topics in clinical psychology. He and his co‐authors emphasized the importance of researching the side effects of psychological interventions. In the current studies (Study 1, N = 58; Study 2, N = 64), we examined clinicians' perspectives on side effects. A slight majority of clinicians in both studies reported familiarity with the topic (Study 1: n = 30, 51%; Study 2: n = 39, 61%). Those who claimed familiarity were more likely to discuss side effects with their patients compared with those who acknowledged a lack of knowledge. In Study 2, we found significant variation among clinicians regarding what constitutes avoidable, unavoidable or nonexistent side effects, and their views did not align with those of patients. This divergence may explain why a considerable number of clinicians refrain from discussing side effects with patients, despite patients' right to be fully informed about the potential benefits and risks of their treatment. Our findings underscore the need for clear guidelines that define the full spectrum of side effects and offer strategies for effective communication with patients. The first step in developing such guidelines is to raise awareness among professionals about the topic, which can be effectively achieved by engaging in the work of Steven J. Lynn and his co‐authors, whose insights remain highly relevant.

SUMMARY: Validity tests are used in both forensic and clinical settings, but their application in clinical practice is often hindered by misconceptions. These include the assumptions that validity tests imply a medico-legal dimension, primarily detect feigning or malingering, and provide minimal actionable information to clinicians. The authors critically discuss these misconceptions and argue that validity tests may offer significant value in clinical practice by assessing whether patients can describe their symptoms, complaints and impairments with reasonable accuracy, which has important implications for diagnosis and treatment planning. Importantly, in clinical practice, when interpreting validity tests, neutral terminology such as ‘over-reporting’ and ‘underperformance’ is often preferable to – and better to substantiate than – terms like ‘feigning’ and ‘malingering’, which can evoke moral judgements, creating an unnecessary barrier to using these valuable clinical tools.

Unwanted events in psychotherapy can hinder treatment, yet clinicians overlook them and tend to attribute treatment stagnation mainly to patient‐related factors. The unwanted events–adverse treatment reaction (UE‐ATR) checklist was developed to encourage a more balanced reflection on treatment difficulties, but its effectiveness remains unclear. This study investigated whether the UE‐ATR checklist enables clinicians to allocate treatment difficulties in a more nuanced way across various contributing factors. Clinicians and psychology students ( N = 104) were randomly assigned to either use the UE‐ATR ( n = 59) or not ( n = 45) while reviewing a case vignette of a patient who experienced unwanted events during therapy and treatment stagnation. They allocated responsibility for suboptimal treatment outcome across five factors: the patient, the therapist, the treatment method, the patient's pathology or other circumstances. Attribution was analysed using the Herfindahl–Hirschman index (HHI), where higher scores indicate a monocausal and lower scores reflect a multicausal view. No significant differences were found between the conditions. Although most users found the checklist clinically useful, this positive perception did not lead to a more balanced perspective on the causes of unwanted events. Although the UE‐ATR checklist can support clinical reflection, additional training is necessary to maximize its effectiveness.

Typically, research on response bias in symptom reports covers two extreme ends of the spectrum: overreporting and underreporting. Yet, little is known about symptom presentation that includes both types of response bias simultaneously (i.e., mixed presentation). We experimentally checked how overreporting, underreporting, and mixed reporting reflect in trauma symptom reports. Undergraduate students (N = 151) were randomly allocated to one of four conditions: control group (n = 40), overreporting (n = 37), underreporting (n = 36), or a mixed reporting (n = 38) group. The control group was asked to be honest, whereas the simulation groups received instructions they were expected to be able to relate to. Participants were administered a PTSD checklist, the Supernormality Scale-Revised, which screens for symptom denial, and the Inventory of Problems-29, which gauges overreporting. For all three measures, group differences were significant (F(3, 147) > 13.78, p_s < . 001, ɳ² > .22), with the overreporting group exhibiting the most severe symptom presentation and the underreporting group endorsing the fewest symptoms, while the mixed group almost perfectly imitated the results of the control group on all measures. Thus, instructing individuals to strategically exhibit both overreporting, to a functional degree, and underreporting results in a symptom presentation that is relatively similar to genuine performance. To optimize accuracy statistics, researchers might want to consider including such mixed group condition in future simulation studies.