It is often necessary for neuropsychologists, clinical psychologists, and other healthcare professionals to assess an individual's capacity to consent to treatment related to healthcare. This task can be challenging and requires a delicate balance of both respect for individuals' autonomy, as well as the protection of individuals with diminished capacity to make an autonomous decision. The purpose of the present review is to provide an overview of the conceptual model of decisional capacity as well as a brief summary of some of the currently available instruments designed to help evaluate medical decision making. In addition, current empirical literature on the relationship between neuropsychological abilities and decision-making capacity is discussed and a brief set of recommendations is provided to further aid clinicians or consultants when they are required to complete the ethically important but difficult task of making determinations about healthcare decision-making capacity.

Population aging is an enormous public health issue and there is clear need for strategies to maximize opportunities for successful aging. Many psychiatric illnesses are increasingly thought to be associated with accelerated aging, therefore emerging data on individual and policy level interventions that alter typical aging trajectories are relevant to mental health practitioners. Although the determinants and definition of successful aging remain controversial, increasing data indicate that psychiatric illnesses directly impact biological aging trajectories and diminish lifestyle, psychological, and socio-environmental factors that seem to reduce risk of morbidity and mortality. Many interventions designed to enhance the normal course of aging may be adjunctive approaches to management of psychiatric illnesses. We highlight recent data on interventions seeking to promote healthy aging, such as cognitive remediation, physical activity, nutrition, and complementary and alternative treatments for older people with and without psychiatric illnesses.

OBJECTIVES:Optimizing the research consent process simultaneously fosters respect for autonomy and protection of those with diminished capacity for autonomy. This study evaluated the effectiveness of an enhanced research consent procedure, employing multimedia disclosure and corrective feedback, in improving decisional capacity among 114 people with mild-to-moderate Alzheimer's disease (AD) and 134 non-psychiatric comparison (NC) subjects. METHODS:Participants were randomized to consent type (routine versus enhanced) and protocol type (lower versus higher risk). Outcomes included a 5-item questionnaire assessing immediate comprehension, MacArthur Competence Assessment Tool for Clinical Research assessing four components of decision-making capacity, and categorical decisional capacity (based on a cut-score established in reference to expert judgments for a subset of participants). RESULTS:There was no significant effect of the enhanced consent procedure, relative to routine consent, on immediate comprehension or decisional capacity. CONCLUSIONS:Multimedia tools do not appear to be the solution to better consent for AD research. CLINICAL IMPLICATIONS:Given the ethical primacy of informed consent and issues of justice for impaired populations who might be harmed by an absence of research-based treatment advances, continued search for ways to more meaningfully engage people with AD in the consent or assent process is warranted.

Objective

Investigators conducting Alzheimer's disease (AD) research need to consider participants' capacity to consent. Cognitive functioning is a significant predictor of decisional capacity, but there is a dearth of information on the influence of neuropsychiatric symptoms in AD on decisional capacity. We examined the rates of decisional capacity associated with two types of research protocols, and the association of capacity with neuropsychiatric symptoms and other participant characteristics.

Methods

We comprehensively evaluated decisional capacity among 64 patients with mild-to-moderate AD and 70 healthy comparison (HC) subjects randomized to consider either a medium risk or higher risk hypothetical research protocol. Additional measures included sociodemographics, cognitive deficits, and neuropsychiatric symptoms.

Results

Twenty AD patients (31.3%) and 67 HCs (95.7%) were deemed capable; 44 AD patients (68.8%) and 3 HCs (4.3%) incapable of consent. Age, education, and severity of cognitive deficits were associated with incapable status; there were no significant associations with severity of neuropsychiatric symptoms or protocol risk level.

Conclusions

Findings highlight the importance of understanding of capacity and its assessment among people with AD, rather than treating AD diagnosis as synonymous with impaired capacity. As novel treatments move from bench to bedside, methods of assessing and addressing capacity impairment must similarly advance.

Clinical implications

In assessing research consent capacity, use structured assessments with population specific cut scores interpreted in the context of the person's background including education, culture, and language. Individuals should be encouraged to execute research proxy documents when able.

Individuals with bipolar disorder (BD) may exhibit attentional deficits, however, the extent of impairment and long-term fluctuations in performance in attention are relatively unknown. We investigated the relationship between sustained attention and affective symptoms over time among BD patients. We also examined whether global differences in attentional capacity differed among BD versus normal comparison (NC) subjects. Participants included 106 outpatients with BD and 66 NC subjects who were administered symptom rating scales and a measure of sustained attention (Continuous Performance Test- Identical Pairs). Measures were repeated 6, 12, and 26 weeks post-baseline. Compared to NC subjects, participants with BD showed impairment in sustained attention across time. Within patient increases in manic symptoms were associated with increased false alarms; both manic and depressive symptoms were associated with worse discrimination. Neither manic nor depressive symptoms were related to hit rates. Our results indicate that the ability to inhibit a response to near miss stimuli (i.e., those that are close to but not identical to the target) is globally impaired among BD patients relative to NC subjects, as well as state-dependent, covarying with affective symptoms. Psychosocial interventions requiring high levels of attentional capacity may need to be adapted according to patients' current symptomatology.

Background

Clinical insight in bipolar disorder is associated with treatment adherence and psychosocial outcome. The short-term dynamics of clinical insight in relationship to symptoms and cognitive abilities are unknown.

Methods

In a prospective observational study, a total of 106 outpatients with bipolar disorder I or II were assessed at baseline, 6 weeks, 12 weeks, and 26 weeks. Participants were administered a comprehensive neuropsychological battery, clinical ratings of manic and depressive symptom severity, and self-reported clinical insight. Lagged correlations and linear mixed-effects models were used to determine the temporal associations between symptoms and insight, as well as the moderating influence of global cognitive abilities.

Results

At baseline, insight was modestly correlated with severity of manic symptoms, but not with depressive symptoms or cognitive abilities. Insight and depressive symptoms fluctuated to approximately the same extent over time. Both lagged correlations and mixed effects models with lagged effects indicated that the severity of manic symptoms predicted worse insight at later assessments, whereas the converse was not significant. There were no direct or moderating influences of global cognitive abilities.

Limitations

Our sample size was modest, and included relatively psychiatrically stable outpatients, followed for a six month period. Our results may not generalize to acutely symptomatic patients followed over a longer period.

Conclusions

Clinical insight varies substantially over time within patients with bipolar disorder. Impaired insight in bipolar disorder is more likely to follow than to precede manic symptoms.

Objective

Obstructive sleep apnea (OSA) is very common in Parkinson's disease (PD). OSA is known to affect patients' cognition. The present study assessed whether PD patients with OSA (PD + OSA) score lower on cognitive measures than those without OSA (PD - OSA). In addition, this study evaluated whether treating the OSA with continuous positive airway pressure (CPAP) in PD + OSA patients results in an improved cognitive functioning.

Methods

Eighty-six patients with PD underwent an overnight polysomnography screen for OSA and were administered the Mini-Mental Status Exam (MMSE) and the Montreal Cognitive Assessment (MoCA). This resulted in 38 patients with PD + OSA who were randomly assigned to receive either therapeutic CPAP for 6 weeks (n = 19) or placebo CPAP for three weeks followed by therapeutic CPAP for three weeks (n = 19). Intervention participants completed a neurocognitive battery at baseline and 3- and 6-week time-points.

Results

Patients with PD + OSA scored significantly lower than PD - OSA on the MMSE and MoCA after controlling for age, education, and PD severity. OSA was a significant predictor of cognition (MMSE p <0.01; MoCA p = 0.028).There were no significant changes between groups in cognition when comparing three weeks of therapeutic CPAP with 3 weeks of placebo CPAP. Comparisons between pre-treatment and 3-week post-therapeutic CPAP for the entire sample also revealed no significant changes on overall neuropsychological (NP) scores.

Conclusions

Findings suggest that PD patients with OSA show worse cognitive functioning on cognitive screening measures than those without OSA. However, OSA treatment after three or six weeks of CPAP may not result in overall cognitive improvement in patients with PD.

Vascular risk factors and cerebral blood flow (CBF) reduction have been linked to increased risk of cognitive impairment and Alzheimer's disease (AD); however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs) previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors), advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor). This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus), inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus), and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus) cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines.

Objective

Deficits in cognitive functioning are related to functional disability in people with serious mental illness. Measures of functional capacity are commonly used as a proxy for functional disabilities for cognitive remediation programs, and robust linear relationships between functional capacity and cognitive deficits are frequently observed. This study aimed to determine whether a curvilinear relationship better approximates the association between cognitive functioning and functional capacity.

Method

Two independent samples were studied. Study 1: participants with schizophrenia (n=435) and bipolar disorder (n=390) aged 18-83 completed a neuropsychological battery and a performance-based measure of functional capacity. Study 2: 205 participants with schizophrenia (age range=39-72) completed a brief neuropsychological screening battery and a performance-based measure of functional capacity. For both studies, linear and quadratic curve estimations were conducted with cognitive performance predicting functional capacity scores.

Results

Significant linear and quadratic trends were observed for both studies. Study 1: in both the schizophrenia and bipolar participants, when cognitive composite z-scores were >0 (indicating normal to above normal performance), cognition was not related to functional capacity. Study 2: when neuropsychological screening battery z-scores were >-1 (indicating low average to average performance), cognition was not related to functional capacity.

Conclusions

These results illustrate that in cognitively normal adults with serious mental illness, the relationship between cognitive function and functional capacity is relatively weak. These findings may aid clinicians and researchers determine who may optimally benefit from cognitive remediation programs, with greater benefits possibly being achieved for individuals with cognitive deficits relative to individuals with normal cognition.