Cognition in major depressive disorder: a 'Systemically Important Functional Index' (SIFI)

Efficacy of antidepressants on measures of workplace functioning in major depressive disorder: A systematic review

INTRODUCTION

Work-related disability and productivity loss in Major Depressive Disorder (MDD) are critical determinants of patient quality of life and contribute significantly to the human and economic costs of MDD. Notwithstanding the return to work and pre-morbid levels of functioning as a critical therapeutic objective among individuals with MDD, it is unclear whether antidepressant treatment significantly and reliably improves measures of workplace functioning. Herein, we investigate to what extent antidepressant treatment improves workplace functioning among adults with MDD.

METHODS

We conducted a systematic review of randomized, double-blind, placebo-controlled or active comparator clinical trials primarily or secondarily investigating the efficacy of antidepressant agents on subjective ratings of workplace functioning and/or measures of work absence.

RESULTS

Thirteen placebo-controlled and four active comparator clinical trials reported on the efficacy of agomelatine, bupropion, desvenlafaxine, duloxetine, fluoxetine, levomilnacipran, paroxetine, sertraline, venlafaxine, or vortioxetine on subjective measures of workplace impairment. Overall, antidepressant treatment improved standardized measures of workplace functioning (e.g., Sheehan Disability Scale-work item). One placebo-controlled trial of agomelatine and one clinical trial comparing the efficacy of vortioxetine to that of venlafaxine had mixed results on measures of work absence.

LIMITATIONS

Included interventional trials evaluated work-related disability as a secondary outcome using subjective rating scales.

CONCLUSION

Extant data suggest that antidepressant treatment improves workplace outcomes in MDD. The capability of antidepressants in improving measures of workplace functioning should be considered in cost-benefit analyses to better inform cost-modelling studies pertaining to antidepressant therapy.

Depressive disorders: Processes leading to neurogeneration and potential novel treatments

Mood disorders are wide spread with estimates that one in seven of the population are affected at some time in their life (Kessler et al., 2012). Many of those affected with severe depressive disorders have cognitive deficits which may progress to frank neurodegeneration. There are several peripheral markers shown by patients who have cognitive deficits that could represent causative factors and could potentially serve as guides to the prevention or even treatment of neurodegeneration. Circadian rhythm misalignment, immune dysfunction and oxidative stress are key pathologic processes implicated in neurodegeneration and cognitive dysfunction in depressive disorders. Novel treatments targeting these pathways may therefore potentially improve patient outcomes whereby the primary mechanism of action is outside of the monoaminergic system. Moreover, targeting immune dysfunction, oxidative stress and circadian rhythm misalignment (rather than primarily the monoaminergic system) may hold promise for truly disease modifying treatments that may prevent neurodegeneration rather than simply alleviating symptoms with no curative intent. Further research is required to more comprehensively understand the contributions of these pathways to the pathophysiology of depressive disorders to allow for disease modifying treatments to be discovered.

Recognition and Treatment of Cognitive Dysfunction in Major Depressive Disorder

Major Depressive Disorder (MDD) is a prevalent, chronic, disabling, and multidimensional mental disorder. Cognitive dysfunction represents a core diagnostic and symptomatic criterion of MDD, and is a principal determinant of functional non-recovery. Cognitive impairment has been observed to persist despite remission of mood symptoms, suggesting dissociability of mood and cognitive symptoms in MDD. Recurrent impairments in several domains including, but not limited to, executive function, learning and memory, processing speed, and attention and concentration, are associated with poor psychosocial and occupational outcomes. Attempts to restore premorbid functioning in individuals with MDD requires regular screenings and assessment of objective and subjective measures of cognition by clinicians. Easily accessible and cost-effective tools such as the THINC-integrated tool (THINC-it) are suitable for use in a busy clinical environment and appear to be promising for routine usage in clinical settings. However, antidepressant treatments targeting specific cognitive domains in MDD have been insufficiently studied. While select antidepressants, e.g., vortioxetine, have been demonstrated to have direct and independent pro-cognitive effects in adults with MDD, research on additional agents remains nascent. A comprehensive clinical approach to cognitive impairments in MDD is required. The current narrative review aims to delineate the importance and relevance of cognitive dysfunction as a symptomatic target for prevention and treatment in the phenomenology of MDD.

Executive Function and Spatial Cognition Mediate Psychosocial Dysfunction in Major Depressive Disorder

Background: Cognitive and psychosocial dysfunction are prevalent and disabling features of Major Depressive Disorder (MDD). Emerging evidence suggests that poor cognitive functioning mediates the negative effect of MDD on psychosocial function. However, there is a lack of research examining the domain-specific nature of this relationship. The current study evaluated whether the relationship between MDD and specific psychosocial subdomains (e.g., autonomy, occupational functioning) was mediated by domain-specific cognitive deficits. Methods: Data from 155 participants was obtained from the Cognitive Function and Mood Study (CoFaMS), a cross-sectional analysis of mood, cognition, social cognition, and functioning in individuals with MDD. Cognitive functioning was assessed (Current MDD n = 45, Healthy n = 110), with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the Colorado Assessment Tests (CATs), and the Psychology Experiment Building Language (PEBL). Psychosocial functioning was clinically evaluated with the Functioning Assessment Short Test (FAST). Results: The results indicated that spatial cognition and executive functioning partially mediated the negative effect of MDD on overall psychosocial functioning, autonomy, and subjective cognition. In contrast, spatial and executive domains showed divergent mediation patterns on interpersonal relationships and leisure time. Conclusions: The findings suggest that executive and spatial cognition play an important role in the pathology of overall psychosocial functioning, and specific functional issues in MDD. Treatments targeting psychosocial recovery in MDD may be improved by emphasizing executive and spatial cognitive remediation.

Neuropsychological predictors of response to cognitive behavioral therapy for posttraumatic stress disorder in persons with severe mental illness

This study examined whether cognitive functioning was related to treatment outcomes in persons with severe mental illness who received a cognitive behavioral therapy (CBT) program for co-occurring posttraumatic stress disorder (PTSD). The study sample was drawn from a larger controlled trial of 108 persons with severe mental illness and PTSD comparing the effects of CBT with treatment as usual on PTSD and related outcomes, with assessments conducted at baseline, post-treatment, and 3- and 6-month follow-ups. Among the 54 persons in CBT, 49 were administered a neuropsychological battery at baseline and 40 were exposed to the CBT program. Statistical analyses of these 40 participants were conducted to evaluate whether cognitive functioning was related to participation in the CBT program, completion of homework assignments, and improvements in PTSD, and other outcomes. Cognitive functioning was not related to participation in CBT or completion of homework. Lower cognitive functioning predicted less learning of information about PTSD at post-treatment and follow-up, but not less clinical benefit from CBT in PTSD diagnosis or symptoms, other symptoms, or health. The results suggest that cognitive impairment does not attenuate response to the CBT for PTSD program in persons with severe mental illness. Clinical Trials.gov Identifier: NCT00053690.

Assessment and Management of Cognitive and Psychosocial Dysfunctions in Patients With Major Depressive Disorder: A Clinical Review

Background: Full functional recovery is defined as a state in which patients are again able to enjoy their usual activities, return to work, and take care of themselves, and it should represent the end goal of treatment in patients with major depressive disorder (MDD). Patients with MDD report many unmet needs, including residual cognitive symptoms, lack of improvement in psychosocial functioning and life satisfaction, even during mood symptom remission. In this paper, we aim to: (a) identify the available assessment tools for evaluating cognitive and psychosocial functioning in patients with MDD; (b) provide an overview of therapeutic options that can improve full functional recovery in MDD also by improving cognitive symptoms. Methods: The relevant databases MEDLINE, ISI Web of Knowledge - Web of Science Index, Cochrane Reviews Library and PsychoINFO were searched for identifying papers on validated tools for the assessment of cognitive and personal functioning in patients with MDD. Results: New assessment tools (such as the THINC-it TOOL, the COBRA, the SCIP-D, and the UPSA-D) have been developed for evaluating the cognitive dysfunction in MDD patients. Adopting these tools in the clinical routine practice is useful to evaluate the improvement in cognitive functioning and, therefore, the achievement of full functioning recovery. The optimal management of patients with MDD include the combination of pharmacological compounds and psychosocial interventions for achieving full functional recovery in patients with MDD. Conclusions: Full functional recovery must be the target of any treatment programme for patients with MDD. In order to achieve this goal, it is necessary to develop personalized treatment and integrate psychosocial and psychopharmacological interventions.

Executive Subdomains Are Differentially Associated With Psychosocial Outcomes in Major Depressive Disorder

Background: Deficits in executive functioning are frequently associated with poor psychosocial outcomes in Major Depressive Disorder (MDD). However, there is a poor understanding of the domain-specific relationships between executive subdomains (e.g., forward planning, decision making) and specific psychosocial issues (e.g., occupational functioning, social relationships). The current study explored these relationships across currently depressed and remitted MDD patients, as well as a healthy control group. Methods: Data from 142 participants were obtained from the Cognitive Functioning and Mood Study (CoFaM-S), a cross sectional study of mood, cognition, and psychosocial functioning in mood disorders. Participants' [current depression n = 31, remitted depression n = 52, healthy controls (HC) n = 59] executive functioning was evaluated with well-established tests of executive subdomains (i.e., Tower of London, card sorting, Stroop task). The Functioning Assessment Short Test (FAST) was employed to clinically evaluate psychosocial dysfunction. Results: The results indicated that forward planning was most strongly associated with psychosocial issues in the current depression group as compared to HCs, while cognitive updating was primary in the remitted group vs. HC. Conclusions: These findings suggest that executive subdomains are deferentially associated with psychosocial issues across different stages of depressive illness, and that forward planning and cognitive updating should be considered in adjunctive cognitive treatment.

Cognitive dysfunction in major depressive disorder

PURPOSE OF REVIEW

The principal aim of this review is to highlight recent advances in our understanding of cognitive dysfunction in major depressive disorder (MDD). We review new assessment and treatment approaches, in which cognition and associated psychosocial dysfunction are considered primary outcomes.

RECENT FINDINGS

Current work suggests that cognitive dysfunction reduces occupational productivity, and interferes broadly with domains of day-to-day and social functioning. These findings imply that cognitive dysfunction interacts with emotional and social factors relevant to MDD. Recent advances in screening instruments enable standardized detection of cognitive symptoms in MDD. Clinical trials suggest that cognitive symptoms are suitable targets and primary outcomes of psychological and pharmacological treatments.

SUMMARY

A growing interest in cognitive dysfunction in MDD has improved our ability to assess and treat MDD. Future research will be strengthened by the use of consistent terminology, standardized cognitive screening, and treatments that target cognitive dysfunction in MDD. Integration of emotional and social treatment strategies may further advance clinical efficacy.

Cognitive impairment as measured by the THINC-integrated tool (THINC-it): Association with psychosocial function in major depressive disorder

BACKGROUND

Psychosocial impairment represents an important treatment target in major depressive disorder (MDD). The majority of patients with MDD do not regain premorbid levels of psychosocial functioning despite the resolution of core depressive symptoms. This study aimed to investigate the respective effects of cognitive function and depression severity on impaired psychosocial function in MDD.

METHODS

Adults aged 18-65 with moderate-to-severe MDD (n = 100) and age-, sex-, and education-matched healthy controls participated in a cross-sectional study validating the THINC-integrated tool (THINC-it), a cognitive screening tool comprised of objective and subjective measures of cognitive function. Depression severity was assessed using the Montgomery-Åsberg Depression Rating Scale and psychosocial function was assessed using the Sheehan Disability Scale (SDS).

RESULTS

Subjects with MDD reported greater impairment in psychosocial function than healthy controls, with significant differences in SDS total and domain scores (ps < .01) after controlling for age, sex, and education. Generalized linear models indicated that subjective cognitive function was most strongly associated with SDS total score (RR = .14, p = .01) and SDS domains of work/school (RR = .15, p = .03), family and home responsibilities (RR = .15, p = .02), and economic days lost (RR = .18, p =.03). Depression severity was most strongly associated with SDS social life (RR = .08, p < .01) and economic days underproductive (RR = .07, p < .01). Objective cognitive function was not significantly associated with any SDS outcomes.

LIMITATIONS

The cross-sectional, observational study design limits temporal inferences. The self-report nature of measures included may have influenced associations observed. Potential medication effects are not noted.

CONCLUSIONS

Cognitive deficits, as measured by the THINC-it, are associated with significant psychosocial impairment in MDD. These results provide empirical support for the assessment of both subjective and objective measures of cognition, as they are not associated with each other and have differential effects on functional trajectory.

Cannabidiol in medical marijuana: Research vistas and potential opportunities

The high and increasing prevalence of medical marijuana consumption in the general population invites the need for quality evidence regarding its safety and efficacy. Herein, we synthesize extant literature pertaining to the phytocannabinoid cannabidiol (CBD) and its brain effects. The principle phytocannabinoid Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and CBD are the major pharmacologically active cannabinoids. The effect of CBD on brain systems as well as on phenomenological measures (e.g. cognitive function) are distinct and in many cases opposite to that of Δ⁹-THC. Cannabidiol is without euphoriant properties, and exerts antipsychotic, anxiolytic, anti-seizure, as well as anti-inflammatory properties. It is essential to parcellate phytocannabinoids into their constituent moieties as the most abundant cannabinoid have differential effects on physiologic systems in psychopathology measures. Disparate findings and reports related to effects of cannabis consumption reflect differential relative concentration of Δ⁹-THC and CBD. Existing literature, notwithstanding its deficiencies, provides empirical support for the hypothesis that CBD may exert beneficial effects on brain effector systems/substrates subserving domain-based phenomenology. Interventional studies with purified CBD are warranted with a call to target-engagement proof-of-principle studies using the research domain criteria (RDoC) framework.

Distinct Antidepressant-Like and Cognitive Effects of Antidepressants with Different Mechanisms of Action in Middle-Aged Female Mice

BACKGROUND

Cognitive dysfunction is among the key symptoms of major depressive disorder and can be affected by antidepressants. Cognitive decline also occurs in normal aging. The effects of different antidepressants on affective and cognitive domains in older subjects are seldom assessed simultaneously.

METHODS

Healthy middle-aged female mice received vehicle or antidepressant (vortioxetine, vilazodone, duloxetine, or fluoxetine) at therapeutic doses. After 1 month treatment, mice were accessed for visuospatial memory and depression-like behavior. A separate cohort of mice received 3 months of treatment and was test for recognition memory and depression-like behavior.

RESULTS

After 1 month treatment, vortioxetine improved visuospatial memory and reduced depression-like behavior. Vilazodone reduced depression-like behavior. Duloxetine and fluoxetine were ineffective in both tests. After 3 months treatment, vortioxetine reduced depression-like behavior without affecting recognition memory, while fluoxetine impaired recognition memory. Duloxetine and vilazodone had no effect in both tests.

CONCLUSION

Different antidepressants have distinct effects in middle-aged female mice.