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.

A Novel Approach to Monitoring Cognitive Adverse Events for Interventional Studies Involving Advanced Dementia Patients: Insights From the Electroconvulsive Therapy for Agitation in Dementia Study

OBJECTIVE

To develop an individualized method for detecting cognitive adverse events (CAEs) in the context of an ongoing trial of electroconvulsive therapy for refractory agitation and aggression for advanced dementia (ECT-AD study).

METHODS

Literature search aimed at identifying (a) cognitive measures appropriate for patients with advanced dementia, (b) functional scales to use as a proxy for cognitive status in patients with floor effects on baseline cognitive testing, and (c) statistical approaches for defining a CAE, to develop CAEs monitoring plan specifically for the ECT-AD study.

RESULTS

Using the Severe Impairment Battery-8 (SIB-8), baseline floor effects are defined as a score of ≤5/16. For patients without floor effects, a decline of ≥6 points is considered a CAE. For patients with floor effects, a decline of ≥30 points from baseline on the Barthel Index is considered a CAE. These values were derived using the standard deviation index (SDI) approach to measuring reliable change.

CONCLUSIONS

The proposed plan accounts for practical and statistical challenges in detecting CAEs in patients with advanced dementia. While this protocol was developed in the context of the ECT-AD study, the general approach can potentially be applied to other interventional neuropsychiatric studies that carry the risk of CAEs in patients with advanced dementia.

Bipolar symptoms, somatic burden and functioning in older-age bipolar disorder: A replication study from the global aging & geriatric experiments in bipolar disorder database (GAGE-BD) project

OBJECTIVES

The Global Aging & Geriatric Experiments in Bipolar Disorder Database (GAGE-BD) project pools archival datasets on older age bipolar disorder (OABD). An initial Wave 1 (W1; n = 1369) analysis found both manic and depressive symptoms reduced among older patients. To replicate this finding, we gathered an independent Wave 2 (W2; n = 1232, mean ± standard deviation age 47.2 ± 13.5, 65% women, 49% aged over 50) dataset.

DESIGN/METHODS

Using mixed models with random effects for cohort, we examined associations between BD symptoms, somatic burden and age and the contribution of these to functioning in W2 and the combined W1 + W2 sample (n = 2601).

RESULTS

Compared to W1, the W2 sample was younger (p < 0.001), less educated (p < 0.001), more symptomatic (p < 0.001), lower functioning (p < 0.001) and had fewer somatic conditions (p < 0.001). In the full W2, older individuals had reduced manic symptom severity, but age was not associated with depression severity. Age was not associated with functioning in W2. More severe BD symptoms (mania p ≤ 0.001, depression p ≤ 0.001) were associated with worse functioning. Older age was significantly associated with higher somatic burden in the W2 and the W1 + W2 samples, but this burden was not associated with poorer functioning.

CONCLUSIONS

In a large, independent sample, older age was associated with less severe mania and more somatic burden (consistent with previous findings), but there was no association of depression with age (different from previous findings). Similar to previous findings, worse BD symptom severity was associated with worse functioning, emphasizing the need for symptom relief in OABD to promote better functioning.

Demographic and clinical associations to employment status in older-age bipolar disorder: Analysis from the GAGE-BD database project

OBJECTIVE

The current literature on employment in older adults with bipolar disorder (OABD) is limited. Using the Global Aging and Geriatric Experiments in Bipolar Disorder Database (GAGE-BD), we examined the relationship of occupational status in OABD to other demographic and clinical characteristics.

METHODS

Seven hundred and thirty-eight participants from 11 international samples with data on educational level and occupational status were included. Employment status was dichotomized as employed versus unemployed. Generalized linear mixed models with random intercepts for the study cohort were used to examine the relationship between baseline characteristics and employment. Predictors in the models included baseline demographics, education, psychiatric symptom severity, psychiatric comorbidity, somatic comorbidity, and prior psychiatric hospitalizations.

RESULTS

In the sample, 23.6% (n = 174) were employed, while 76.4% were unemployed (n = 564). In multivariable logistic regression models, less education, older age, a history of both anxiety and substance/alcohol use disorders, more prior psychiatric hospitalizations, and higher levels of BD depression severity were associated with greater odds of unemployment. In the subsample of individuals less than 65 years of age, findings were similar. No significant association between manic symptoms, gender, age of onset, or employment status was observed.

CONCLUSION

Results suggest an association between educational level, age, psychiatric severity and comorbidity in relation to employment in OABD. Implications include the need for management of psychiatric symptoms and comorbidity across the lifespan, as well as improving educational access for people with BD and skills training or other support for those with work-life breaks to re-enter employment and optimize the overall outcome.

Bipolar I and bipolar II subtypes in older age: Results from the Global Aging and Geriatric Experiments in Bipolar Disorder (GAGE-BD) project

OBJECTIVES

The distinction between bipolar I disorder (BD-I) and bipolar II disorder (BD-II) has been a topic of long-lasting debate. This study examined differences between BD-I and BD-II in a large, global sample of OABD, focusing on general functioning, cognition and somatic burden as these domains are often affected in OABD.

METHODS

Cross-sectional analyses were conducted with data from the Global Aging and Geriatric Experiments in Bipolar Disorder (GAGE-BD) database. The sample included 963 participants aged ≥50 years (714 BD-I, 249 BD-II). Sociodemographic and clinical factors were compared between BD subtypes including adjustment for study cohort. Multivariable analyses were conducted with generalized linear mixed models (GLMMs) and estimated associations between BD subtype and (1) general functioning (GAF), (2) cognitive performance (g-score) and (3) somatic burden, with study cohort as random intercept.

RESULTS

After adjustment for study cohort, BD-II patients more often had a late onset ≥50 years (p = 0.008) and more current severe depression (p = 0.041). BD-I patients were more likely to have a history of psychiatric hospitalization (p < 0.001) and current use of anti-psychotics (p = 0.003). Multivariable analyses showed that BD subtype was not related to GAF, cognitive g-score or somatic burden.

CONCLUSION

BD-I and BD-II patients did not differ in terms of general functioning, cognitive impairment or somatic burden. Some clinical differences were observed between the groups, which could be the consequence of diagnostic definitions. The distinction between BD-I and BD-II is not the best way to subtype OABD patients. Future research should investigate other disease specifiers in this population.

Symptom Severity Mixity in Older-Age Bipolar Disorder: Analyses From the Global Aging and Geriatric Experiments in Bipolar Disorder Database (GAGE-BD)

OBJECTIVE

Some individuals with bipolar disorder (BD) experience manic and depressive symptoms concurrently, but data are limited on symptom mixity in older age bipolar disorder (OABD). Using the Global Aging & Geriatric Experiments in Bipolar Disorder Database, we characterized mixity in OABD and associations with everyday function.

METHODS

The sample (n = 805), from 12 international studies, included cases with both mania and depression severity ratings at a single timepoint. Four mixity groups were created: asymptomatic (A), mixed (Mix), depressed only (Dep), and manic only (Man). Generalized linear mixed models used mixity group as the predictor variable; cohort was included as a random intercept. Everyday function was assessed with the Global Assessment of Functioning score.

RESULTS

Group proportions were Mix (69.6%; n = 560), followed by Dep (18.4%; n = 148), then A (7.8%; n = 63), then Man (4.2%; n= 34); levels of depression and mania were similar in Mix compared to Dep and Man, respectively. Everyday function was lowest in Mix, highest in A, and intermediate in Man and Dep. Within Mix, severity of depression was the main driver of worse functioning. Groups differed in years of education, with A higher than all others, but did not differ by age, gender, employment status, BD subtype, or age of onset.

CONCLUSIONS

Mixed features predominate in a cross-sectional, global OABD sample and are associated with worse everyday function. Among those with mixed symptoms, functional status relates strongly to current depression severity. Future studies should include cognitive and other biological variables as well as longitudinal designs to allow for evaluation of causal effects.

Identifying Delirium in Persons With Moderate or Severe Dementia: Review of Challenges and an Illustrative Approach

Delirium and dementia are common causes of cognitive impairment among older adults, which often coexist. Delirium is associated with poor clinical outcomes, and is more frequent and more severe in patients with dementia. Identifying delirium in the presence of dementia, also described as delirium superimposed on dementia (DSD), is particularly challenging, as symptoms of delirium such as inattention, cognitive dysfunction, and altered level of consciousness, are also features of dementia. Because DSD is associated with poorer clinical outcomes than dementia alone, detecting delirium is important for reducing morbidity and mortality in this population. We review a number of delirium screening instruments that have shown promise for use in DSD, including the 4-DSD, combined Six Item Cognitive Impairment Test (6-CIT) and 4 'A's Test (4AT), Confusion Assessment Method (CAM), and the combined UB2 and 3D-CAM (UB-CAM). Each has advantages and disadvantages. We then describe the operationalization of a CAM-based approach in a current ECT in dementia project as an example of modifying an existing instrument for patients with moderate to severe dementia. Ultimately, any instrument modified will need to be validated against a standard clinical reference, in order to fully establish its sensitivity and specificity in the moderate to severe dementia population. Future work is greatly needed to advance the challenging area of accurate identification of delirium in moderate or severe dementia.

Comparing continuous and harmonized measures of depression severity in older adults with bipolar disorder: Relationship to functioning

OBJECTIVE

Harmonizing different depression severity scales often requires creation of categorical variables that may decrease the sensitivity of the measure. Our aim was to compare the associations between categorical and continuous and harmonized measures of depression and global functioning in a large dataset of older age patients with bipolar disorder (OABD).

METHOD

In the Global Aging & Geriatric Experiments in Bipolar Disorder Database (GAGE-BD) the 17-item Hamilton Depression scale (HAM-D), Montgomery Asberg Depression Rating Scale (MADRS) or the Center for Epidemiological Studies Depression scales (CES-D) was used to assess current depressive symptoms, while the Global Assessment of Functioning (GAF) assessed functional status. Data were harmonized from 8 OABD studies (n = 582). In each subsample, the relationship of depression severity as a continuous and categorical measure was compared to GAF. In the total sample, harmonized ordinal depression categories were compared to GAF.

RESULTS

Effect size and variance explained by the model for the categorical measure in the total sample was higher than both the categorical and continuous measure in the CES-D subsample, higher than the categorical but lower than the continuous measure in the HAM-D subsample, and lower than both the categorical and continuous measures in the MADRS subsample.

LIMITATIONS

All included studies have different inclusion and exclusion criteria, study designs, and differ in aspects of sociodemographic variables.

CONCLUSIONS

Associations were only slightly larger for the continuous vs categorical measures of depression scales. Harmonizing different depression scales into ordinal categories for analyses is feasible without losing statistical power.

Bipolar symptoms, somatic burden, and functioning in older-age bipolar disorder: Analyses from the Global Aging & Geriatric Experiments in Bipolar Disorder Database project

OBJECTIVE

Literature on older-age bipolar disorder (OABD) is limited. This first-ever analysis of the Global Aging & Geriatric Experiments in Bipolar Disorder Database (GAGE-BD) investigated associations among age, BD symptoms, comorbidity, and functioning.

METHODS

This analysis used harmonized, baseline, cross-sectional data from 19 international studies (N = 1377). Standardized measures included the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HAM-D), Montgomery-Asberg Depression Rating Scale (MADRS), and Global Assessment of Functioning (GAF).

RESULTS

Mean sample age was 60.8 years (standard deviation [SD] 12.2 years), 55% female, 72% BD I. Mood symptom severity was low: mean total YMRS score of 4.3 (SD 5.4) and moderate-to-severe depression in only 22%. Controlled for sample effects, both manic and depressive symptom severity appeared lower among older individuals (p's < 0.0001). The negative relationship between older age and symptom severity was similar across sexes, but was stronger among those with lower education levels. GAF was mildly impaired (mean =62.0, SD = 13.3) and somatic burden was high (mean =2.42, SD = 1.97). Comorbidity burden was not associated with GAF. However, higher depressive (p < 0.0001) and manic (p < 0.0001) symptoms were associated with lower GAF, most strongly among older individuals.

CONCLUSIONS

Findings suggest an attenuation of BD symptoms in OABD, despite extensive somatic burden. Depressive symptom severity was strongly associated with worse functioning in older individuals, underscoring the need for effective treatments of BD depression in older people. This international collaboration lays a path for the development of a better understanding of aging in BD.

Cognition in older adults with bipolar disorder: An ISBD task force systematic review and meta-analysis based on a comprehensive neuropsychological assessment

OBJECTIVES

We aim to characterize the cognitive performance in euthymic older adults with bipolar disorder (OABD) through a comprehensive neuropsychological assessment to obtain a detailed neuropsychological profile.

METHODS

We conducted a systematic search in MEDLINE/Pubmed, Cochrane, and PsycInfo databases. Original studies assessing cognitive function in OABD (age ≥50 years ) containing, at a minimum, the domains of attention/processing speed, memory, and executive functions were included. A random-effects meta-analysis was conducted to summarize differences between patients and matched controls in each cognitive domain. We also conducted meta-regressions to estimate the impact of clinical and socio-demographic variables on these differences.

RESULTS

Eight articles, providing data for 328 euthymic OABD patients and 302 healthy controls, were included in the meta-analysis. OABD showed worse performance in comparison with healthy controls, with large significant effect sizes (Hedge's g from -0.77 to -0.89; p < 0.001) in verbal learning and verbal and visual delayed memory. They also displayed statistically significant deficits, with moderate effect size, in processing speed, working memory, immediate memory, cognitive flexibility, verbal fluency, psychomotor function, executive functions, attention, inhibition, and recognition (Hedge's g from -0.52 to -0.76; p < 0.001), but not in language and visuoconstruction domains. None of the examined variables were associated with these deficits.

CONCLUSIONS

Cognitive dysfunction is present in OABD, with important deficits in almost all cognitive domains, especially in the memory domain. Our results highlight the importance of including a routine complete neuropsychological assessment in OABD and also considering therapeutic strategies in OABD.

Cannabinoids for Agitation in Alzheimer's Disease

Agitation is a common neuropsychiatric symptom of Alzheimer's disease (AD) that greatly impacts quality of life and amplifies caregiver burden. Agitation in AD may be associated with volume loss in the anterior cingulate cortex, posterior cingulate cortex, insula, amygdala, and frontal cortex, as well as with degeneration of monoaminergic neurotransmission, disrupted circadian rhythms, and frailty. Current pharmacologic options have troubling safety concerns and only modest efficacy. There is increasing interest in cannabinoids as promising agents due to preclinical and early clinical research that suggest cannabinoids can elicit anxiolytic, antidepressant, and/or anti-inflammatory effects. Cannabinoids may relieve agitation by regulating neurotransmitters, improving comorbidities and circadian rhythms, and increasing cerebral circulation. Here we discuss the possible contributory mechanisms for agitation in AD and the therapeutic relevance of cannabinoids, including CBD and THC.

Clinical Trials and Tribulations in the COVID-19 Era

Advances in treating and preventing Alzheimer disease and other neurocognitive disorders of aging arise from rigorous preclinical and clinical research, with randomized controlled treatment trials as the last and definitive test. The COVID-19 pandemic has greatly disrupted ongoing interventional studies and researchers are scrambling to find ways to safely continue this critical work amidst rapidly shifting guidelines from sponsors, institutions, and state and federal guidelines. Here the authors describe novel approaches and work-flow adaptations to study visits, drug delivery and interim and endpoint safety and outcomes assessments to avoid sacrificing years of preparation and substantial financial investments, to work in the best interest of participants and their caregivers, and to continue on the path toward discovering disease-modifying treatments for the millions of individuals impacted by major neurocognitive disorders.

Inhibiting reactions to emotional versus non-emotional response cues in schizophrenia: Insights from a motor-process paradigm

Recent models of schizophrenia suggest deficient use of contextual response cues when confronted with countermanding emotional cues. It is important to clinically validate these models by testing patients diagnosed with schizophrenia on tasks with competing emotional and contextual response determinants. Control and schizophrenia groups completed a novel task that elicited motor responses consistent with, or in opposition to, pre-potent emotional actions (i.e., approach vs. avoidance). An analogous non-emotional task was also used to examine cue-conflict impairment more generally. The groups demonstrated statistically equivalent performance decrements on incongruent versus congruent trials on both tasks. However, within the schizophrenia group, the incongruency effect was significantly greater in the emotional versus non-emotional task. These data suggest that, while patients with schizophrenia were able to employ contextual response cues to override competing emotional responses, they were slower to resolve emotional versus non-emotional response conflict. When patients were subdivided according to the presence or absence of disorganized symptoms, this effect was confined to patients with disorganized symptoms.

Psychological characteristics of individuals who put forth inadequate cognitive effort in a secondary gain context

The current study sought to characterize the psychological architecture of individuals who put forth inadequate effort. The Minnesota Multiphasic Personality Inventory, 2nd Edition-Restructured Form was used to identify dimensions of psychological functioning in a mixed outpatient sample of U.S. Veterans referred for neuropsychological evaluation as part of their clinical care. After accounting for external financial incentive and symptom overreporting, results showed that the inadequate effort group (n = 23, mean age = 42.48) scored higher than the adequate effort group (n = 29, mean age = 44.31) on neurologic complaints (NUC) and lower on behavioral/externalizing dysfunction (BXD), antisocial behaviors (RC4), and disconstraint (DISC-r). Lower scores on BXD, RC4, and DISC-r could indicate higher behavioral constraint-a psychological characteristic that has been linked to the pursuit of high-value future rewards. Alternatively, lower scores on these scales could have reflected a self-presentation strategy aimed at minimizing externalizing and RC4 in order to appear more psychological healthy. Implications of each of these interpretations are discussed.

Reduced directed forgetting for negative words suggests schizophrenia-related disinhibition of emotional cues

BACKGROUND

Several psychological and neurobiological models imply that patients with schizophrenia (SCZ) are more inclined to utilize emotional cues as response determinants to the detriment of more task-appropriate cognitive or contextual cues. However, there is a lack of behavioural data from human clinical studies to support this assertion. Therefore, it is important to evaluate the performance of persons with SCZ using tasks designed to index the resolution between competing emotional and cognitive determinants of goal-directed behaviour.

METHOD

The current study employed a list-method, emotional directed-forgetting (DF) paradigm designed to invoke inhibitory mechanisms necessary to override emotional memory enhancement for successful task completion. Four psycholinguistically matched lists were constructed that were comprised of five negative, five positive, and five neutral words.

RESULTS

Compared with healthy controls, individuals with SCZ showed a reduced DF effect overall. When broken down according to valence, this effect was only observed for negative words, which, in turn, resulted from reduced forgetting of list 1 words following the forget cue.

CONCLUSIONS

These results indicate that individuals with SCZ were less able to engage strategic inhibitory mechanisms for the purpose of overriding recall of negative stimuli when tasks demand call for such action. Thus, our data support the theoretical assertion that SCZ patients have difficulty utilizing cognitive or contextual cues as determinants of goal-directed behaviour in the face of countermanding emotional cues.

CE verbal episodic memory impairment in schizophrenia: a comparison with frontal lobe lesion patients

Schizophrenia (SCZ)-related verbal memory impairment is hypothesized to be mediated, in part, by frontal lobe (FTL) dysfunction. However, little research has contrasted the performance of SCZ patients with that of patients exhibiting circumscribed frontal lesions. The current study compared verbal episodic memory in patients with SCZ and focal FTL lesions (left frontal, LF; right frontal, RF; and bi-frontal, BF) on a four-trial list learning task consisting of three lists of varying semantic organizational structure. Each dependent variable was examined at two levels: scores collapsed across all four trials and learning scores (i.e., trial 4-trial 1). Performance deficits were observed in each patient group across most dependent measures at both levels. Regarding patient group differences, SCZ patients outperformed LF/BF patients (i.e., either learning scores or scores collapsed across trial) on free recall, primacy, primary memory, secondary memory, and subjective organization, whereas they only outperformed RF patients on the semantically blocked list on recency and primary memory. Collectively, these results indicate that the pattern of memory performance is largely similar between patients with SCZ and those with RF lesions. These data support tentative arguments that verbal episodic memory deficits in SCZ may be mediated by frontal dysfunction in the right hemisphere.

Navigational conversation impairs concurrent distance judgments

Dual-task performance as it relates to driving, such as tuning a radio or manipulating a cellular phone, forces drivers to divide their attention between the traffic demands and the in-car task. The present study investigated how concurrent spatial or non-spatial cognitive distractions mediated proximity judgments using vehicular stimuli. Utilizing a modified version of the task employed by [Elias, L.J., Robinson, B. in press. Drive on the right side of the road: perceptual asymmetries for judgments of automobile proximity. International Journal of Neuroscience.] the current study examined how mental navigation (spatial distraction) affected accuracy and response time for depth judgments on vehicular stimuli in each visual field. These were compared to a control condition in which no distraction was present, as well as when a semantic (non-spatial) distraction was present. We found that conversation of a navigational nature (i.e., spatial distraction) most negatively impacted accuracy and response time when processing dynamically changing vehicle proximity. Further, these deleterious effects appeared to be uniform throughout the visual field. Findings are related to driving while being distracted, with particular emphasis on the role of cerebral lateralization in dual-task performance.