The relationship between personality and cognition in older adults with and without early-onset depression.

Introduction: It is well established that personality traits impact cognition, as certain personality factors are associated with performance in specific cognitive domains. However, the findings on the relationships between the Big Five traits and cognition are mixed. Additionally, few studies have explored these relationships in older adults with a history of depression. The present study aimed to (a) evaluate the impact of the Big Five personality traits in older adults with and without a lifetime history of depression; and (b) test the hypotheses that higher trait neuroticism would correlate negatively with cognitive performance, while openness to experience would correlate positively with cognition. Methods: The sample consisted of 138 participants between the ages of 55 and 78 (M = 65.56, SD = 6.36). Sixty-two participants met criteria for current or remitted Major Depressive Disorder, while 76 had no history of depression or other mental health disorders. Participants underwent comprehensive neuropsychological testing. Personality was assessed using the NEO Personality Inventory-Revised (NEO-PI-R), while depression status was determined using the Structured Clinical Interview for DSM-5 (SCID-5). Following a series of Pearson correlations of cognitive variables and the five personality factors, linear regression models were estimated for each significant correlation. Demographic variables (i.e., age, education and sex) were entered in block 1, depression status (never vs. ever) was entered in block 2, and the personality factor score, or sub-facet was entered in block 3. Results: Neuroticism was not associated with cognitive performance on any outcome measure. The facets Openness to Feelings and Openness to Values were positively related to phonemic fluency. Further Openness to Values was positively related to cognitive flexibility. Discussion: Our results suggest that older people who are (a) more capable of identifying and understanding their feelings and the feelings of others, and (b) who are more willing to re-examine social, political, and religious values perform stronger on tasks measuring verbal fluency and cognitive flexibility, which are aspects of executive functioning. Interventions that aim to enhance open mindedness in older adults may have a parallel impact on improving executive functioning, though this would need to be examined prospectively.

Treatment resistant late-life depression: A narrative review of psychosocial risk factors, non-pharmacological interventions, and the role of clinical phenotyping.

BACKGROUND: Treatment resistant depression (TRD) is a subset of major depressive disorder (MDD) in which symptoms do not respond to front line therapies. In older adults, the assessment and treatment of TRD is complicated by psychosocial risk factors unique to this population, as well as a relative paucity of research. METHODS: Narrative review aimed at (1) defining TRLLD for clinical practice and research; (2) describing psychosocial risk factors; (3) reviewing psychological and non-pharmacological treatments; (4) discussing the role of clinical phenotyping for personalized treatment; and (5) outlining research priorities. RESULTS: Our definition of TRLLD centers on response to medication and neuromodulation in primary depressive disorders. Psychosocial risk factors include trauma and early life adversity, chronic physical illness, social isolation, personality, and barriers to care. Promising non-pharmacological treatments include cognitive training, psychotherapy, and lifestyle interventions. The utility of clinical phenotyping is highlighted by studies examining the impact of comorbidities, symptom dimensions (e.g., apathy), and structural/functional brain changes. LIMITATIONS: There is a relative paucity of TRLLD research. This limits the scope of empirical data from which to derive reliable patterns and complicates efforts to evaluate the literature quantitatively. CONCLUSIONS: TRLLD is a complex disorder that demands further investigation given our aging population. While this review highlights the promising breadth of TRLLD research to date, more research is needed to help elucidate, for example, the optimal timing for implementing risk mitigation strategies, the value of collaborative care approaches, specific treatment components associated with more robust response, and phenotyping to help inform treatment decisions.

Evaluation of Post-COVID-19 Cognitive Dysfunction: Recommendations for Researchers.

This Viewpoint provides recommendations for assessment of post­COVID-19 cognitive dysfunction to improve understanding of the pathophysiology of the condition and develop appropriate interventions.

Combinatorial Pharmacogenomic Testing Improves Outcomes for Older Adults With Depression.

(Reprinted with permission from Am J Geriatr Psychiatry 2020; 28:933-945).

Revisiting Apathy in Alzheimer's Disease: From Conceptualization to Therapeutic Approaches.

Apathy is a neurobehavioral syndrome characterized by impaired motivation for goal-directed behaviors and cognitive activity, alongside blunted affect. Apathy is a common neuropsychiatric syndrome in Alzheimer's disease (AD), with a 5-year prevalence over 70%. Apathy also serves as a prognostic indicator, correlating with the progression of AD. Despite advances in its conceptualization and understanding of its neural basis, there is very limited empirical evidence to support the available strategies for the treatment of apathy in AD. Given its complex pathophysiology, including distinct substrates for different apathy dimensions (affective, cognitive, and behavioral), it is unlikely that a single pharmacological or nonpharmacological strategy will be effective for all cases of apathy in AD. High-quality evidence research is needed to better understand the role of specific strategies aiming at a personalized approach.

Combinatorial Pharmacogenomic Testing Improves Outcomes for Older Adults With Depression.

OBJECTIVE: Evaluate the clinical utility of combinatorial pharmacogenomic testing for informing medication selection among older adults who have experienced antidepressant medication failure for major depressive disorder (MDD). DESIGN: Post hoc analysis of data from a blinded, randomized controlled trial comparing two active treatment arms. SETTING: Psychiatry specialty and primary care clinics across 60 U.S. community and academic sites. PARTICIPANTS: Adults age 65 years or older at baseline (n = 206), diagnosed with MDD and inadequate response to at least one medication on the combinatorial pharmacogenomic test report during the current depressive episode. INTERVENTION: Combinatorial pharmacogenomic testing to inform medication selection (guided-care), compared with treatment as usual (TAU). OUTCOMES: Mean percent symptom improvement, response rate, and remission rateat week 8, measured using the 17-item Hamilton Depression Rating Scale; medication switching; and comorbidity moderator analysis. RESULTS: At week 8, symptom improvement was not significantly different for guided-care than for TAU (∆ = 8.1%, t = 1.64, df = 187; p = 0.102); however, guided-care showed significantly improved response (∆ = 13.6%, t = 2.16, df = 187; p = 0.032) and remission (∆ = 12.7%, t = 2.49, df = 189; p = 0.014) relative to TAU. By week 8, more than twice as many patients in guided-care than in TAU were on medications predicted to have no gene-drug interactions (χ2 = 19.3, df = 2; p <0.001). Outcomes in the guided-care arm showed consistent improvement through the end of the open-design 24-week trial, indicating durability of the effect. Differences in outcomes between arms were not significantly impacted by comorbidities. CONCLUSIONS: Combinatorial pharmacogenomic test-informed medication selection improved outcomes over TAU among older adults with depression.

A Lifespan Model of Interference Resolution and Inhibitory Control: Risk for Depression and Changes with Illness Progression.

The cognitive processes involved in inhibitory control accuracy (IC) and interference resolution speed (IR) or broadly - inhibition - are discussed in this review, and both are described within the context of a lifespan model of mood disorders. Inhibitory control (IC) is a binary outcome (success or no for response selection and inhibition of unwanted responses) for any given event that is influenced to an extent by IR. IR refers to the process of inhibition, which can be manipulated by task design in earlier and later stages through use of distractors and timing, and manipulation of individual differences in response proclivity. We describe the development of these two processes across the lifespan, noting factors that influence this development (e.g., environment, adversity and stress) as well as inherent difficulties in assessing IC/IR prior to adulthood (e.g., cross-informant reports). We use mood disorders as an illustrative example of how this multidimensional construct can be informative to state, trait, vulnerability and neuroprogression of disease. We present aggregated data across numerous studies and methodologies to examine the lifelong development and degradation of this subconstruct of executive function, particularly in mood disorders. We highlight the challenges in identifying and measuring IC/IR in late life, including specificity to complex, comorbid disease processes. Finally, we discuss some potential avenues for treatment and accommodation of these difficulties across the lifespan, including newer treatments using cognitive remediation training and neuromodulation.

Memory differences by sex, but not by previous diagnosis of major depressive disorder.

Memory difficulties are consistently reported in Major Depressive Disorder (MDD). Nonetheless, it has not been thoroughly investigated as to whether these deficits persist during remission from MDD. A group of 32 healthy young adults with no history of a mood disorder (Mage = 20.8, SD = 2.1) and 62 remitted depressed young adults (Mage = 21.1, SD = 1.9) completed a neuropsychological battery. The test battery included two measures of nonverbal memory, two measures of verbal memory, and a measure of performance validity. The testing session was repeated three to six weeks later to determine performance stability. No differences were found between healthy controls and remitted depressed patients in either memory domain (all ps > .05) and improvement in performance was exhibited over time for both groups (p = 0.004). Potential practice effects are examined. We found a stronger performance for women than men (p = 0.003), particularly for the Semantic List Learning Task (SLLT) (p = .047). Verbal and nonverbal memory and effort may not be impacted in those who are in a remitted state of MDD, early in the course of the illness. Women demonstrated auditory memory superiority over men, similar to prior research.

Linking late life depression and Alzheimer's disease: mechanisms and resilience.

PURPOSE OF REVIEW: This review summarizes recent literature linking Alzheimer's disease (AD) and late life depression (LLD). It describes shared neurobiological features associated with both conditions, as well as factors that may increase resilience to onset and severity of cognitive decline and AD. Finally, we pose a number of future research directions toward improving detection, management, and treatment of both conditions. RECENT FINDINGS: Epidemiological studies have consistently shown a significant relationship between LLD and AD, with support for depression as a prodromal feature of AD, a risk factor for AD, and observation of some shared risk factors underlying both disease processes. Three major neurobiological features shared by LLD and AD include neurodegeneration, disruption to cerebrovascular functioning, and increased levels of neuroinflammation. There are also potentially modifiable factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve. SUMMARY: We propose that, in the context of depression, neurobiological events, such as neurodegeneration, cerebrovascular disease, and neuroinflammation result in a brain that is more vulnerable to the consequences of the pathophysiological features of AD, lowering the threshold for the onset of the behavioral presentation of AD (i.e., cognitive decline and dementia). We discuss factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve. We conclude with a discussion of future research directions.

A Critical Review and Synthesis of Clinical and Neurocognitive Effects of Noninvasive Neuromodulation Antidepressant Therapies.

There is a plethora of current and emerging antidepressant therapies in the psychiatric armamentarium for the treatment of major depressive disorder. Noninvasive neuromodulation therapies are one such therapeutic category; they typically involve the transcranial application of electrical or magnetic stimulation to modulate cortical and subcortical brain activity. Although electroconvulsive therapy (ECT) has been used since the 1930s, with the prevalence of major depressive disorder and treatment-resistant depression (TRD), the past three decades have seen a proliferation of noninvasive neuromodulation antidepressant therapeutic development. The purpose of this critical review was to synthesize information regarding the clinical effects, neurocognitive effects, and possible mechanisms of action of noninvasive neuromodulation therapies, including ECT, transcranial magnetic stimulation, magnetic seizure therapy, and transcranial direct current stimulation. Considerable research has provided substantial information regarding their antidepressant and neurocognitive effects, but their mechanisms of action remain unknown. Although the four therapies vary in how they modulate neurocircuitry and their resultant antidepressant and neurocognitive effects, they are nonetheless useful for patients with acute and chronic major depressive disorder and TRD. Continued research is warranted to inform dosimetry, algorithm for administration, and integration among the noninvasive neuromodulation therapies and with other antidepressant strategies to continue to maximize their safety and antidepressant benefit.

Ventral prefrontal cortex and emotion regulation in aging: A case for utilizing transcranial magnetic stimulation.

OBJECTIVES: The ventrolateral prefrontal cortex (vlPFC) has been speculated to play an important role in complex processes that allow emotional factors to influence human cognition. Accumulating evidence from human neuroimaging studies, in conjunction with studies of patients with lesions and animal models, shed light on the role of the vlPFC in emotion regulation (ER). This review aims to discuss and integrate recent findings related to vlPFC's role in ER in the context of aging, drawing from diverse sources, and suggest future directions for research utilizing transcranial magnetic stimulation (TMS). METHODS/DESIGN: We summarize findings from the existing literature investigating the neural basis of frontal-lobe mediated ER and then highlight major findings from recent studies directly comparing healthy younger and older adult groups. We conclude by pointing to unaddressed questions worth pursuing in future research. RESULTS AND DISCUSSION: We propose future research directions utilizing TMS to answer key unaddressed questions. Moreover, we discuss the potential advantages, challenges, and limitations of using TMS as a complement to the existing neuroimaging methods in ER.

Examining HPA-axis functioning as a mediator of the relationship between depression and cognition across the adult lifespan.

Altered HPA-axis functioning is a hypothesized mechanism for worsened cognition in depression. The current study examines the indirect effects of depression on processing speed, executive functioning, and memory as a function of the HPA-axis. 38 individuals with a depression diagnosis and 50 healthy controls (HCs) aged 18-86 underwent neuropsychological testing and at-home diurnal salivary cortisol collection. Depression was assessed via structured clinical interviews and rating scales. Cognitive composite scores were derived from factor analysis. Daytime cortisol exposure was estimated using area under the curve (AUC). Depression was associated with higher cortisol levels and slower processing speed . A significant suppression effect of AUC was present on the relationship between depression and processing speed. Limitations include the cross-sectional design and limited sample heterogeneity. Though poorly modulated HPA-axis is one proposed mechanism of cognitive alterations in depression, our results did not support this conclusion for processing speed. Alternative mechanisms should be considered to inform interventions to target cognitive alterations in depression.

Social-emotional aspects of quality of life in multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory auto-immune disease of the central nervous system. It leads to many impairments including physical, cognitive, psychological, and social challenges. Our study examined gender and cultural associations with quality of life (QoL), personal characteristics, and benefits from having MS among those with MS. The study was conducted in Austria and the United States. The sample included 128 participants, 64 in each country, of whom 78 were women and 50 were men aged between 20 and 57 years. We used standard statistical tests, including analyses of covariance (ANCOVA) and partial correlations for the analysis of quantitative data. For the qualitative part of the survey we used semi-structured interviews, which we transcribed and coded to identify categories in the answers for qualitative analyses. Austrian participants with MS perceived a higher social-emotional QoL in comparison to American participants. American participants expressed a higher self-esteem in comparison to Austrian participants. Men reported a lower ability to express love than women. Independent of sex/gender and nationality, participants reported benefits through the disease, especially with regard to improved compassion, mindfulness, improved family relations and lifestyle gains. The qualitative interviews revealed additional gender differences for coping with the illness; and in experiences, expectations, and challenges related to MS. These insights can be used to develop targeted psychological and social support interventions aimed toward improving social-emotional QoL for persons with MS.

Integrated cross-network connectivity of amygdala, insula, and subgenual cingulate associated with facial emotion perception in healthy controls and remitted major depressive disorder.

Emotion perception deficits could be due to disrupted connectivity of key nodes in the salience and emotion network (SEN), including the amygdala, subgenual anterior cingulate cortex (sgACC), and insula. We examined SEN resting-state (rs-)fMRI connectivity in rMDD in relation to Facial Emotion Perception Test (FEPT) performance. Fifty-two medication-free people ages 18 to 23 years participated. Twenty-seven had major depressive disorder (MDD) in remission (rMDD, 10 males), as MDD is associated with emotion perception deficits and alterations in rsfMRI. Twenty-five healthy controls (10 males) also participated. Participants completed the FEPT during fMRI, in addition to an 8-minute eyes-open resting-state scan. Seed regions of interest were defined in the amygdala, anterior insula and sgACC. Multiple regression analyses co-varied diagnostic group, sex and movement parameters. Emotion perception accuracy was positively associated with connectivity between amygdala seeds and regions primarily in the SEN and cognitive control network (CCN), and also the default mode network (DMN). Accuracy was also positively associated with connectivity between the sgACC seeds and other SEN regions, and the DMN, particularly for the right sgACC. Connectivity negatively associated with emotion perception was mostly with regions outside of these three networks, other than the left insula and part of the DMN. This study is the first to our knowledge to demonstrate relationships between facial emotion processing and resting-state connectivity with SEN nodes and between SEN nodes and regions located within other neural networks.