Cognitive impairment in the remitted state of unipolar depressive disorder: A systematic review
ABSTRACT It is unclear whether cognitive impairment is prevalent in the remitted state of unipolar disorder.
To evaluate whether cognitive function is impaired in the remitted state in patients with unipolar depression compared with healthy control individuals, and to investigate the association to prior course of illness, i.e. the number, duration and severity of prior depressive episodes.
Systematic search on existing on-line databases and hand-search of original published papers.
A total of 11 studies fulfilled the selection criteria and were included in the review, including a total of 500 patients remitted from unipolar depression and 471 healthy control individuals. In nine of the eleven studies performance on neuropsychological tests was found to be decreased in patients compared to healthy control individuals in at least one of the tests. Methodological drawbacks were prevalent including non-stringent definition of remission and non-correction for multiple testing. Only few studies investigated the association between cognition and prior course of illness and the results were divergent.
Stringent criteria were used in the assessment of eligibility of studies. The studies were first and foremost selected according to the criteria for remission used.
Cognitive dysfunction seems to be present in individuals suffering from unipolar disorder in the remitted state. We recommend that future studies should focus on disentangling the state and trait characteristics of cognitive dysfunction in unipolar disorder and further clarify the associations with clinical phenotype, course of illness and subsyndromal psychopathology. Furthermore, there is a need to identify the cognitive difficulties in individuals suffering from unipolar disorder in relation to psychosocial function, quality of life and risk of recurrence and to assess the effect of treatment intervention on cognitive function.
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- "The lack of significant correlations between change in cognitive function and change in depression severity, along with the lack of significant between-group differences in depression severity (both objective and subjective) at posttreatment, also suggests that the observed improved cognition in the NCRT group cannot be explained by improved mood. This is consistent with recent reviews showing poor association between depression severity and cognitive function (Hasselbalch et al., 2011; McClintock et al., 2010). We may also speculate that computerized NCRT improves targeted cognitive function independently from mood variation. "
ABSTRACT: Major depression is the most prevalent psychiatric disorder with high relapse rates. When mood can improve or fully recover, the neurocognitive difficulties associated with depression often persist, preventing complete functional recovery. They have also been shown to predict relapse. The efficacy of neurocognitive remediation therapy (NCRT) to rehabilitate cognition has been demonstrated in several clinical populations but randomized controlled trials (RCTs) have not been conducted in depression. The present study aimed to test the feasibility and to conduct a pilot protocol testing for an RCT of computerized NCRT for inpatients with major depressive episode. The feasibility assessment demonstrated excellent acceptance of randomization and very satisfactory recruitment and compliance rates. The RCT procedures' assessment was overall consistent with a successful pilot study with the condition of protocol modification in terms of resources. Preliminary outcome data suggested specific NCRT efficacy to improve targeted neurocognitive processes in depression.The Journal of nervous and mental disease 07/2015; DOI:10.1097/NMD.0000000000000337 · 1.81 Impact Factor
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- "h cognitive performance for some domains may improve during remission of depressive symptoms ( Biringer et al . , 2005 , 2007 ; Story et al . , 2008 ; Hammar and Årdal , 2012 ; Lahr et al . , 2014 ) most studies demonstrate incomplete cognitive recovery ( Beats et al . , 1996 ; Nebes et al . , 2000 ; Portella et al . , 2003 ; Yuan et al . , 2008 ; Hasselbalch et al . , 2011 ) . Heterogeneity of cognitive deficits during acute versus remitted states has raised the question of whether these deficits are state - ( present during acute states ) or trait - ( present both in acute and remitted states ) related . However , a limitation of previous studies has been that participants have been followed for relative"
ABSTRACT: Cognitive deficits in old-age depression vary as a function of multiple factors; one rarely examined factor is long-term psychiatric history. We investigated effects of psychiatric history on cognitive performance in old-age depression and in remitted persons. In the population-based Swedish National Study on Aging and Care in Kungsholmen study, older persons (≥60 years) without dementia were tested with a cognitive battery and matched to the Swedish National Inpatient Register (starting 1969). Participants were grouped according to current depression status and psychiatric history and compared to healthy controls (n = 96). Group differences were observed for processing speed, attention, executive functions, and verbal fluency. Persons with depression and psychiatric inpatient history (n = 20) and late-onset depression (n = 49) performed at the lowest levels, whereas cognitive performance in persons with self-reported recurrent unipolar depression (n = 52) was intermediate. Remitted persons with inpatient history of unipolar depression (n = 38) exhibited no cognitive deficits. Heart disease burden, physical inactivity, and cumulative inpatient days modulated the observed group differences in cognitive performance. Among currently depressed persons, those with inpatient history, and late onset performed at the lowest levels. Importantly, remitted persons showed no cognitive deficits, possibly reflecting the extended time since the last admission (m = 15.6 years). Thus, the present data suggest that cognitive deficits in unipolar depression may be more state- than trait-related. Information on profiles of cognitive performance, psychiatric history, and health behaviors may be useful in tailoring individualized treatment.Frontiers in Psychology 06/2015; 6:865. DOI:10.3389/fpsyg.2015.00865 · 2.80 Impact Factor
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- "In an examination of 428 responders (defined as 50% or greater reduction in overall depressive symptoms, but failure to achieve symptomatic remission) from the Sequenced Treatment Alternatives to Relieve Depression (STAR n D) study, 69.6% of patients reported concentration/decision-making difficulties despite a response to 12 weeks of citalopram treatment (McClintock et al., 2010). Evidence suggests that cognitive impairments persist during symptomatic remission as well (Hasselbalch et al., 2011). These findings have now led to an enhanced interest in identifying treatments that will specifically target cognitive impairments in order to increase remission rates, as well as promote resolution of functional impairment. "
ABSTRACT: Cognitive dysfunction has been repeatedly observed in major depressive disorder (MDD), particularly in areas of attention, verbal and nonverbal learning and memory, and executive functioning. Exercise has been shown to improve cognitive outcomes in other populations, including age-associated cognitive decline, but has not to our knowledge been investigated as an augmentation strategy in depression. This study evaluated the effectiveness of exercise augmentation on cognitive performance in persons with MDD and residual symptoms that included cognitive complaints following initial treatment with a selective serotonin reuptake inhibitor (SSRI). Participants enrolled in the Treatment with Exercise Augmentation for Depression (TREAD) study were randomized to receive either a low or high dose exercise regimen. TREAD participants who provided informed consent for the current study completed Cambridge Neuropsychological Test Automated Battery measures assessing Attention, Visual Memory, Executive Function/Set-shifting and Working Memory, and Executive Function/Spatial Planning domains. Data were analyzed for 39 participants completing both baseline and Week 12 cognitive testing. Overall tests indicated a significant task x group x time interaction for the Executive Function/Set-shifting and Working Memory domain. Post hoc tests indicated improvements in high dose exercisers’ spatial working memory, but decreases in spatial working memory and set-shifting outcomes in low dose exercisers. Both groups improved on measures of psychomotor speed, attention, visual memory and spatial planning. This study suggests a dose-response effect of exercise in specific executive function and working memory tasks among depressed persons with a partial response to SSRI and cognitive complaints, with some cognitive functions improving regardless of exercise dose.European Neuropsychopharmacology 10/2014; 25(2). DOI:10.1016/j.euroneuro.2014.10.001 · 5.40 Impact Factor