Episodic memory functioning in a community-based sample of old adults with major depression: utilization of cognitive support

Neural Circuitry-Neurogenesis Coupling Model of Depression

Depression is characterized by the disruption of both neural circuitry and neurogenesis. Defects in hippocampal activity and volume, indicative of reduced neurogenesis, are associated with depression-related behaviors in both humans and animals. Neurogenesis in adulthood is considered an activity-dependent process; therefore, hippocampal neurogenesis defects in depression can be a result of defective neural circuitry activity. However, the mechanistic understanding of how defective neural circuitry can induce neurogenesis defects in depression remains unclear. This review highlights the current findings supporting the neural circuitry-regulated neurogenesis, especially focusing on hippocampal neurogenesis regulated by the entorhinal cortex, with regard to memory, pattern separation, and mood. Taken together, these findings may pave the way for future progress in neural circuitry-neurogenesis coupling studies of depression.

Depressive Symptom Dimensions and Their Association with Hippocampal and Entorhinal Cortex Volumes in Community Dwelling Older Adults

Objective: Research has shown that depression is a risk factor for Alzheimer’s disease (AD) and subsequent cognitive decline. This is compounded by evidence showing an association between depression and reduced hippocampal volumes; a primary structure implicated in the pathogenesis of the disease. Less is known about the relationship between depression and other AD vulnerable regions such as the entorhinal cortex. Given the heterogeneity of depressive symptom presentation, we examined whether symptom dimensions were associated with hippocampal and entorhinal cortex volumes in community dwelling older adults.

Methods: Eighty-one community dwelling adults completed the Beck Depression Inventory – second edition and underwent structural neuroimaging. Measures of hippocampal and entorhinal cortex volumes were obtained using FreeSurfer software. Linear regression models included regions of interest as dependent variables, with depressive symptom dimensions, as independent variables, controlling for total intracranial volumes, age, education, and gender.

Results: Somatic symptoms were negatively associated with total, right, and left hippocampal volumes. Affective symptoms were negatively associated with total entorhinal cortex volumes, with a marginal main effect on left entorhinal cortex volumes.

Conclusion: Our findings provide support for examining depressive symptoms and their association with AD vulnerable regions along subdimensions of affective, cognitive, and somatic symptoms to better understand profiles of symptoms most associated with these regions. Conceptualizing depressive symptoms in this way may also better inform treatment approaches in terms of targeting types of symptoms that may be more closely linked to poorer brain and cognitive health outcomes.

Is episodic memory performance more vulnerable to depressive affect in older adulthood?

This study examined how age, depressive symptoms, demographic variables, frailty, and health factors jointly influence episodic memory across the lifespan in two large, diverse samples. Hierarchical regression analyses from both samples showed that depressive symptoms negatively impacted episodic memory performance with the effect being more pronounced for older adults. Health and frailty tended not to be associated with episodic memory. However, the main effect of depressive symptoms tended to remain significant over and above other predictors, while the interaction with age was weakened with the addition of demographic variables. The unique contribution of this study is demonstrating that the relationship between depressive symptoms and episodic memory is moderated by age across relatively large non-clinical lifespan samples of adults. The findings indicate the importance of measuring and studying depressive symptoms during the course of aging in order to better understand the complex relationship between age, affect, physical functioning, and memory.

Memory support strategies and bundles: A pathway to improving cognitive therapy for depression?

OBJECTIVE

Therapist use of memory support (MS) alongside treatment-as-usual, with the goal of enhancing patient recall of treatment contents, has been of recent interest as a novel pathway to improve treatment outcome. The memory support intervention (MSI) involves treatment providers' using 8 specific MS strategies to promote patient memory for treatment. The present study examines to what extent therapist use of MS strategies and bundles improves patient recall of treatment contents and treatment outcome.

METHOD

The data were drawn from a pilot RCT reported elsewhere. Participants were 48 adults (mean age = 44.27 years, 29 females) with major depressive disorder (MDD), randomized to receive 14 sessions of either CT + Memory Support (n = 25) or CT-as-usual (n = 23). Therapist use of MS was coded using the Memory Support Rating Scale. Patient memory and treatment outcomes were assessed at baseline, midtreatment (patient recall only), posttreatment, and 6-month follow-up.

RESULTS

Participants in CT + Memory Support received significantly higher amount of MS relative to CT-as-usual. Although not reaching statistical significance, small-to-medium effects were observed between MS strategies and patient recall in the expected direction. Although MS variables were not significantly associated with changes in continuous depressive symptoms, MS was associated with better global functioning. MS also exhibited small to medium effects on treatment response and recurrence in the expected direction but not on remission, though these effects did not reach statistical significance.

CONCLUSIONS

These results provide initial empirical evidence supporting an active method for therapists to implement MS strategies. (PsycINFO Database Record

The development and validation of the Memory Support Rating Scale

Patient memory for treatment information is poor, and worse memory for treatment information is associated with poorer clinical outcomes. Memory support techniques have been harnessed to improve patient memory for treatment. However, a measure of memory support used by treatment providers during sessions has yet to be established. The present study reports on the development and psychometric properties of the Memory Support Rating Scale (MSRS)-an observer-rated scale designed to measure memory support. Adults with major depressive disorder (MDD; N = 42) were randomized to either cognitive therapy plus memory support (CT + MS; n = 22) or cognitive therapy as-usual (CT-as-usual; n = 20). At posttreatment, patients freely recalled treatment points via the patient recall task. Sessions (n = 171) were coded for memory support using the MSRS, 65% of which were also assessed for the quality of cognitive therapy via the Cognitive Therapy Rating Scale (CTRS). A unidimensional scale composed of 8 items was developed using exploratory factor analysis, though a larger sample is needed to further assess the factor structure of MSRS scores. High interrater and test-retest reliabilities of MSRS scores were observed across 7 MSRS coders. MSRS scores were higher in the CT + MS condition compared with CT-as-usual, demonstrating group differentiation ability. MSRS scores were positively associated with patient recall task scores but not associated with CTRS scores, demonstrating convergent and discriminant validity, respectively. Results indicate that the MSRS yields reliable and valid scores for measuring treatment providers' use of memory support while delivering cognitive therapy. (PsycINFO Database Record

Effects of psychiatric history on cognitive performance in old-age depression

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.

Preserved cognitive function after 12 months of treatment with rivastigmine in mild Alzheimer's disease in comparison with untreated AD and MCI patients

Cholinesterase inhibitors (ChEIs) have shown positive symptomatic effects on cognition, activities of daily living, and behavior in patients with Alzheimer's disease (AD). Rivastigmine is a slowly reversible ChEI that inhibits acetylcholinesterase and butyrylcholinesterase. We evaluated the effects of long-term rivastigmine treatment on cognitive function and plasma levels of ChE activity, and the relationship between ChE activity and cognition. Patients with mild AD (n = 11) treated with rivastigmine for 12 months were compared with matched groups of untreated patients with AD (n = 21) or mild cognitive impairment (MCI; n = 22) representing the natural course of the pre-clinical and very early stage of disease. For untreated AD patients, neuropsychological assessment was made at baseline and 12 months. Determination of ChE activity in plasma and assessment of global cognition, episodic memory, visuospatial ability, and attention were performed at 0 (baseline), 3, 6, and 12 months for treated AD patients and untreated MCI patients. At 12 months, cognitive function was slightly improved or maintained in mild AD patients treated with rivastigmine. In contrast, cognition was markedly worsened in untreated AD patients and unchanged or slightly worsened in untreated MCI patients. In the group of treated AD patients, there was a significant correlation between plasma ChE inhibition and cognition, particularly in relation to attention. This effect was most apparent at 3 months of treatment. In conclusion, a clear beneficial effect of rivastigmine was shown on cognitive function for patients with mild AD and plasma values of ChE inhibition were associated with attention.

Impaired Motor Speed, Visuospatial Episodic Memory and Verbal Fluency Characterize Cognition in Long-Term Stroke Survivors: The Tromsø Study

The cognitive function after stroke is examined in acute and subacute phase, but poorly characterized in long-term stroke survivors. This paper discusses cognitive function among long-term stroke survivors, with matched stroke-free subjects, based on a population survey. General cognition, verbal, executive and visuospatial function, memory, attention, and motor speed were tested as well as motor function in upper extremities. Stroke survivors and controls were most effectively discriminated by means of motor speed, followed by visuospatial episodic memory and verbal fluency. This pattern of cognitive disturbances may be a consequence of cerebral lesions in frontal subcortical areas, and is different from Alzheimer's disease.