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

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.