Alzheimer's disease (AD) affects neurological, cognitive, and behavioral processes. Thus, to accurately assess this disease, researchers and clinicians need to combine and incorporate data across these domains. This presents not only distinct methodological and statistical challenges but also unique opportunities for the development and advancement of psychometric techniques. In this article, we describe relatively recent research using item response theory (IRT) that has been used to make progress in assessing the disease across its various symptomatic and pathological manifestations. We focus on applications of IRT to improve scoring, test development (including cross-validation and adaptation), and linking and calibration. We conclude by describing potential future multidimensional applications of IRT techniques that may improve the precision with which AD is measured.

Objectives Neuropsychiatric symptoms (NPS) are common among individuals with dementia of the Alzheimer’s type (DAT). We sought to characterize which NPS more purely relate to cognitive dysfunction in DAT, relative to other NPS. Method Demographic, neurocognitive, neuroimaging, and NPS data were mined from the Alzheimer’s Disease Neuroimaging Initiative database (n = 906). Using factor analysis, we analyzed the degree to which individual NPS were associated with DAT-associated cognitive dysfunction. We also employed item response theory to graphically depict the ability of individual NPS to index DAT-associated cognitive dysfunction across a continuum ranging from cognitively normal to mild DAT. Results Psychotic symptoms (hallucinations and delusions) were more strongly related to the continuum of DAT-associated cognitive dysfunction than other NPS, with the strength of the relationship peaking at high levels of disease severity. Psychotic symptoms also negatively correlated with brain volume and did not relate to the presence of vision problems. Aberrant motor behavior and apathy had relatively smaller associations with DAT-associated cognitive dysfunction, while other NPS showed minimal associations. Discussion Psychotic symptoms most strongly indexed DAT-associated cognitive dysfunction, whereas other NPS, such as depression and anxiety, were not as precisely related to the DAT-associated cognitive dysfunction.

Our statistically derived models of the AD pathological cascade are consistent with existing theoretical models.

Objective Health literacy is a strong psychosocial determinant of health disparities and has been found to relate to various aspects of health-related technology use. With the increased implementation of neuropsychological services performed via telehealth during the coronavirus disease 2019 pandemic, the relationship between health literacy and comfort with teleneuropsychology warrants further investigation. Method The present study examined 77 Veterans participating in neuropsychological evaluations as a part of standard clinical care. The sample was diverse in terms of age ethnicity, and psychiatric and neurocognitive diagnoses. In addition to a fixed-flexible neuropsychological battery, the Brief Health Literacy Screening Tool (BRIEF) was administered to evaluate health literacy. Self-reported comfort with the teleneuropsychological evaluation was assessed using an informal 10-point scale, and qualitative comfort responses were also recorded. Results Independent samples t-tests revealed older adults were more likely to participate in the evaluation via telephone than with VA Video Connect. Although health literacy was not related to telehealth modality, it was correlated with comfort with the teleneuropsychological evaluation (r = .34, p < .01), although it is notable that average comfort levels were high across modalities (M = 8.16, SD = 2.50). Conclusions Findings support the notion that teleneuropsychological services may feasibly be implemented with a diverse group of patients, although flexibility with modality may be necessary. Those performing these services should also be aware that patients with lower health literacy may feel less comfortable with teleneuropsychology as they seek to build rapport and optimize evaluation engagement.

Obsessive compulsive disorder (OCD) is an anxiety disorder characterized by repeated, unwanted thoughts and behaviors. Individuals with this condition often experience significant emotional distress secondary to their symptoms. Additionally, impairments in attention/concentration, processing speed, and executive functions are typically observed. The exact pathology of OCD remains unknown; consequently, it can be difficult to treat patients with severe symptomatology. Deep brain stimulation (DBS) may be a viable treatment option for individuals who do not respond to medication and/or cognitive behavioral therapy. The following case discusses DBS of the anterior limb of the internal capsule for a patient with severe, therapy-refractory OCD, including pre- to postoperative neurocognitive and psychiatric changes.