The effects of depression and anxiety on memory performance.

The effects of depression and anxiety, as assessed by MMPI D and Pt scales, on memory performance was examined in 3999 veterans who completed the California Verbal Learning Test (CVLT). Depressive symptoms (without anxiety) had an adverse effect on immediate recall of new information and the total amount (but not rate) of acquisition; however, retrieval and retention were unaffected. On the other hand, high levels of anxiety did not have significant detrimental effects on any aspect of memory functioning assessed including immediate recall, total amount acquired, retention, and retrieval of novel information. However, when depression was compounded by anxiety, there was not only an adverse effect on immediate recall and amount (but not rate) of acquisition, but also on the retrieval of newly learned information. We conclude that the presence of comorbid anxiety may, in part, account for the variability in previous research findings regarding the effects of depression on memory functioning.     

Temporal effects of dehydroepiandrosterone sulfate on memory formation in day-old chicks

Dehydroepiandrosterone sulfate (DHEAS) has been shown to enhance memory retention in different animal models and in various learning paradigms. In the present study, we investigated the effect of peripherally administered DHEAS on the acquisition, consolidation and retention of memory using a weak version of the one-trial passive avoidance task in day-old chicks. Intraperitoneally administered DHEAS (20 mg/kg) either 30 min before or 30 min and 4.5 h after training on the weakly aversive stimulus, enhanced recall at 24 h following training, suggesting a potentiation of not only the acquisition but also the early and late phases of memory consolidation. In contrast, when DHEAS was administered at 30 min prior to the 24 h retention test there was no memory enhancement, indicating a lack of effect on memory retrieval. Memory recall was unaltered when DHEAS was administered at 30 min before training in a control group trained on a strongly aversive stimulus, confirming memory-specific effects. Interestingly, the memory enhancement appeared to be sex-specific as male chicks showed higher recall than females. These findings provide further evidence that DHEAS enhances memory and may be involved in the temporal cascade of long-term memory formation.     

The effects of idealized fitness images on anxiety, depression and global mood states in college age males and females

The primary purpose of this investigation was to quantify the effects of fitness media exposure on psychological affect utilizing the Solomon 4-group design. Volunteers were counterbalanced and randomly assigned to 30 minutes of viewing either a fitness or control magazine. State anxiety (STAI), tension, depression, anger vigor, fatigue, confusion, and global mood (POMS) were measured. Results indicate that pre-test sensitization was not a significant factor when testing the psychological factors in this investigation. Additionally, the outcomes associated with viewing ultra-fit images in popular media are not a benign experience and merit further examination.     

Effects of estrogen and progesterone on spatial memory consolidation in aged females

Interpretation of data illustrating that estrogen, with or without progestin, is detrimental to memory in post-menopausal women is complicated by the fact that little is known about the effects of progestins on memory. The present study examined if estrogen, alone or with progesterone, affects spatial memory consolidation in ovariectomized aged female mice. Mice received eight training trials in a spatial Morris water maze followed immediately by injection of water-soluble 17beta-estradiol (E(2); 0.2 mg/kg) or vehicle. Mice were re-tested 24 h later. All mice learned to find the platform on Day 1. On Day 2, the performance of control, but not E(2) mice, deteriorated, suggesting that E(2) enhanced memory for the platform location. In a second experiment, mice were injected with E(2) and 10 or 20 mg/kg water-soluble progesterone. The 10 mg/kg dose of progesterone did not affect estrogen's ability to enhance spatial memory consolidation, but 20 mg/kg blocked this effect. These data indicate that estrogen can improve spatial memory consolidation in aged females and that this effect can be attenuated by progesterone.     

Short-term memory and cognitive variability in adult fragile X females

We investigated the possibility that adult fragile X [fra(X)] heterozygotes have a distinct or specific cognitive profile, with a particular focus on visuospatial and/or memory deficits. With a sample of 13 adult fra(X) female carriers (2 fra(X) positive) and age-matched control women, we performed 2 tests: Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Revised Visual Retention Test (RVRT). An identifiable cognitive profile was not evident in the study group, but significant differences were evident in RVRT performance in number correct and number of errors when compared to controls and normative data. The combination of the WAIS-R and RVRT data suggests that the short-term memory component of the tasks may be of more significance than visuospatial performance in the deficits observed.     

Source memory in major depression.

BACKGROUND: Research demonstrating episodic memory deficits in clinical depression has dealt with item memory exclusively. The present research sought to determine whether memory for source is differentially affected by depression. METHODS: Patients with major depression and normal control subjects were examined in item memory and two types of source memory, requiring discriminations between (e.g. something that the subject said and something another person said) and within (e.g. something that one person said and something another person said) classes. RESULTS: Depression-related deficits in item memory were exacerbated in source memory. However, deficits in source memory in depressed patients were restricted to those conditions requiring within-class discriminations. CONCLUSION: The overall pattern of results may reflect that those symptoms of major depression that affect the individuals basic processing resources (e.g. concentration difficulties, lack of effort, loss of energy) results in an impairment of episodic memory, particularly when the demands of differentiating perceptual and cognitive information are high.     

Recall and recognition memory deficits in depression.

The aim of the present study was to establish the nature of memory deficits of depressive subjects in word learning tests. A word learning test consisting of 1, 3 or 5 learning trials was used. We found that patients were characterized by inferior memory recall compared to controls when 5 learning trials were given. Patients performed significantly slower than controls on a recognition test but both patients and controls recognized the same number of words. This suggests that the memory deficits that are present in many depressive subjects may be restricted to impaired active retrieval from memory. A second experiment revealed that recognition memory and delayed recall as well as immediate recall were impaired in depressive patients after 1 learning trial. These short-comings vanished after 3 trials, except for immediate recall. These data suggest that not only retrieval but also encoding of information into memory may be impaired in depression, especially in the beginning of a task when demands on cognitive effort are high. The results are discussed in terms of resource allocation and demands on effort that may change in the course of a task.     

Behavioural stages in memory formation

Day-old chickens trained in pairs on an aversive discrimination task yielded a retention function with two points of reduced retention, at 15 and 55 min after learning. These points of temporary reduction in retention were interpreted as reflecting change-over of recall from three successive phases in memory formation. Chicks trained in isolation showed the same retention function as paired chicks except that the second point of reduced retention occurred at 70 min after learning. It was suggested that isolation prolonged the availability for recall of the second phase of memory formation. The findings are consistent with and support a three phase, behaviourally sequentially dependent, model of memory formation previously postulated on the basis of pharmacological studies.     

DNA methylation and memory formation

Memory formation and storage require long-lasting changes in memory-related neuronal circuits. Recent evidence indicates that DNA methylation may serve as a contributing mechanism in memory formation and storage. These emerging findings suggest a role for an epigenetic mechanism in learning and long-term memory maintenance and raise apparent conundrums and questions. For example, it is unclear how DNA methylation might be reversed during the formation of a memory, how changes in DNA methylation alter neuronal function to promote memory formation, and how DNA methylation patterns differ between neuronal structures to enable both consolidation and storage of memories. Here we evaluate the existing evidence supporting a role for DNA methylation in memory, discuss how DNA methylation may affect genetic and neuronal function to contribute to behavior, propose several future directions for the emerging subfield of neuroepigenetics, and begin to address some of the broader implications of this work.     

Verbal learning and memory among heterozygous fragile X females.

In this paper we report the results of a brief examination of verbal learning and memory in 20 heterozygous fragile X [fra(X)] positive females and in 2 control groups of 20 subjects each. One control group was composed of fra(X)-negative mothers (obligate carriers) and sisters of male probands with fra(X) syndrome, while the other consisted of 14 head injured and 6 learning disabled females. Intellectual functioning was assessed by means of the Wechsler scales, and learning was assessed by several different clinical memory tests. Significant differences were found between groups on measures of short-term memory and learning efficiency. Groups did not differ on measures of cued recall or delayed recall. The findings are consistent with other data and suggest the possibility that central information processing and/or specific encoding processes are defective in persons with fra(X).     

In two species, females exhibit superior working memory and inferior reference memory on the water radial-arm maze

Male and female mice and rats were tested on a water escape version of the radial-arm maze designed to measure working and reference memory. In both species, females exhibited superior working memory during acquisition, and were better able to handle a higher memory load. However, male mice and rats exhibited better reference memory than females during the asymptotic portion of testing. Our data suggest that females may be better at working memory when both working and reference memory information must be learned simultaneously, and males better at reference memory when it has been differentiated from working memory.     

The impact of clinical depression on working memory

Introduction. Both Channon, Baker, and Robertson (1993) and Hartlage, Alloy, Vazquez, and Dykman (1993) claim that working memory impairment in depressed patients is limited to Baddeley's (1996) central executive and does not affect either the phonological loop or the visuospatial scratchpad. Our key questions were: (1) is there an impairment of working memory in depression and which elements does it effect; (2) is another major clinical group also affected and in what ways, and finally, (3) how do these groups vary when compared with each other and with normals? Thus we sought to locate a depression-specific effect and define its extent. Methods. We tested 35 depressed patients, using both 24 anxiety patients and 29 normal controls as comparisons. Several tasks were used so that we could differentiate between the three key aspects of working memory. Results. Contrary to Channon et al., we found that depression affects the allocation of attention and all elements of working memory. The depression group showed a distinct performance profile, with impairments occurring on measures of both the phonological loop and visuospatial sketch pad. On measures of central executive functioning, both depression and anxiety groups showed comparable levels of impairment when compared with the control group. Conclusions. We propose that the source of general disruption in both depressed and anxious patients may be a competition between attempts to direct attentional resources to the task in hand and away from the distractive and intrusive effects of automatic negative thoughts.     

Decentring and distraction reduce overgeneral autobiographical memory in depression

BACKGROUND: Increased recall of categorical autobiographical memories is a phenomenon unique to depression and post-traumatic stress disorder, and is associated with a poor prognosis for depression. Although the elevated recall of categorical memories does not change on remission from depression, recent findings suggest that overgeneral memory may be reduced by cognitive interventions and maintained by rumination. This study tested whether cognitive manipulations could influence the recall of categorical memories in dysphoric participants. METHODS: Forty-eight dysphoric and depressed participants were randomly allocated to rumination or distraction conditions. Before and after the manipulation, participants completed the Autobiographical Memory Test, a standard measure of overgeneral memory. Participants were then randomized to either a 'decentring' question (Socratic questions designed to facilitate viewing moods within a wider perspective) or a control question condition, before completing the Autobiographical Memory Test again. RESULTS: Distraction produced significantly greater decreases in the proportion of memories retrieved that were categorical than rumination. Decentring questions produced significantly greater decreases in the proportion of memories retrieved that were categorical than control questions, with this effect independent of the prior manipulation. CONCLUSIONS: Elevated categorical memory in depression is more modifiable than has been previously assumed; it may reflect the dynamic maintenance of a cognitive style that can be interrupted by brief cognitive interventions.     

Estrogen-mediated Height Control in Girls with Marfan Syndrome

This study evaluated the efficacy of a stepwise regimen of estradiol valerate for height control in girls with Marfan syndrome. Eight girls with Marfan syndrome who had completed estrogen treatment for height control were included. Estradiol valerate was started at a dose of 2 mg/day, and then was increased. The projected final height was estimated using the initial height percentile (on a disease-specific growth curve for Korean Marfan syndrome [gcPFHt]), and the initial bone age (baPFHt). After the estrogen treatment, the projected final height was compared to the actual final height (FHt). The median baseline chronological and bone age were 10.0 and 10.5 years, respectively. After a median of 36.5 months of treatment, the median FHt (172.6 cm) was shorter than the median gcPFHt (181.0 cm) and baPFHt (175.9 cm). In the six patients who started treatment before the age of 11 years, the median FHt (171.8 cm) was shorter than the median gcPFHt (181.5 cm) and baPFHt (177.4 cm) after treatment. The median differences between the FHt and gcPFHt and baPFHt were 9.2 and 8.3 cm, respectively. In two patients started treatment after the age of 11, the differences between FHt and gcPFHt, and baPFHt after treatment were -4 and 1.4 cm, and -1.2 and 0 cm for each case, respectively. A stepwise increasing regimen of estradiol valerate may be an effective treatment for height control in girls with Marfan syndrome, especially when started under 11 years old.     

Estrogen-mediated neuroprotection in the cortex may require NMDA receptor activation

Several studies have suggested that a potential mechanism for estrogen-mediated neuroprotection following experimental stroke is a result of modulating glutamate-mediated excitotoxicity. Our laboratory has shown that in male rats, estrogen injection (systemic or direct intracortical injection) resulted in an immediate depolarization of cortical neurons. Therefore, the present study was designed to investigate whether the estrogen-induced depolarization of cortical neurons was required in mediating the early events associated with this neuroprotection. We tested this hypothesis by co-injecting selective antagonists of the NMDA (MK-801) or AMPA (DNQX) glutamatergic receptors with estrogen. Systemic injection of estrogen significantly attenuated the MK-801-induced decrease in infarct volume following middle cerebral artery occlusion (MCAO). Similarly, when estrogen and MK-801 were co-injected directly into the cortex, no neuroprotection was observed. However, when estrogen or MK-801 was injected centrally 10 min prior to the injection of the other drug, significant neuroprotection was observed. This led us to hypothesize that estrogen-mediated neuroprotection required an initial activation of NMDA receptors. Furthermore, our results suggest that this estrogen-mediated neuroprotection was also associated with a significant increase in m-calpain and activation of an endoplasmic reticulum (ER) specific caspase-12. Finally, the results of current clamp experiments showed that estrogen significantly depolarized cortical neurons as well as enhanced NMDA-induced depolarization. Taken together, these results suggest that estrogen pretreatment may activate NMDA receptors resulting in modification of ER-associated molecular mechanisms involved in neuroprotection following MCAO.     

Neuropeptide effects on memory in aged monkeys

The effects of several neuropeptides were evaluated using a non-human primate model of age-related memory impairments. Several doses of ACTH4-10, lysine vasopressin, arginine vasopressin, oxytocin and somatostatin were each tested in several aged monkeys. Because data from a large number of non-drug control sessions was collected before, during and after this study, it was possible to define the normal range of control performance for each monkey and statistically determine whether a change in performance under any single dose of drug reflected a significant change from the particular monkey's normal baseline performance. Although none of the neuropeptides produced consistent group effects, evaluations of individual subjects against their own baseline performance revealed reliable changes at certain doses. Arginine vasopressin appeared to produce the best overall effects with three of the five monkeys exhibiting reliable changes in performance from baseline. These same three monkeys also responded positively to the lysine form. Oxytocin impaired memory in three of the six aged monkeys tested over a wide range of doses. Three of six aged monkeys performed better under ACTH4-10 compared to baseline; however, in two of these cases only a single dose was effective. The performance of only one subject was improved under somatostatin, and this was at a single dose only. The data reported here provide evidence for neuropeptides producing behavioral improvement in non-human primates using an appetitive task, eliminating a popular criticism that the data in this literature has depended too heavily on the testing of rodents in shock-motivated tasks. Additionally, the improvements observed in this study involve a behavior that it naturally impaired by age and one which has many operational similarities and some empirical relevance to measures of recent memory in humans. However, these positive findings must be tempered by the lack of robust effects and high individual variation observed.