Mood Disorders In Later Life Research Articles

Gut–neuroimmune interactions: the unexpected role of the immune system in brain development

How does the immune system impact brain development? The exciting and somewhat unexpected relationship between the immune system and the brain has become one of the most fascinating topics in neuroscience. Even though the immune system was initially implicated in resolving viral and bacterial threats, it is now becoming more evident that it also plays a role in processes in the brain, both under healthy and pathological conditions. This novel role of the immune system in brain health has been implicated in various psychopathologies where neurodevelopment, stress and mood are central. In particular, its role in healthy brain development is becoming more evident, and understanding neuroimmune communication is becoming crucial in treating neurodevelopmental and mood disorders in later life. In the brain, glia function as part of the innate immune system and are programmed to respond to pathogens and physical injury. They also play an important role in neuronal development and pruning. These cells communicate with and respond to chemical signals, such as cytokines and chemokines, which can then initiate or downregulate inflammatory responses. Finally, the trillions of microbes residing in the gut can also stimulate cytokine and chemokine responses in the periphery and play an important role in both immunity and brain development.

Future-Oriented Thought Patterns Associated With Anxiety and Depression in Later Life: The Intriguing Prospects of Prospection.

Anxiety and mood disorders in later life are the focus of an increasing amount of intervention research, however basic mechanisms and paradigms explaining etiology and maintenance warrant further exploration. Research on future-oriented thought patterns associated with anxiety and depression in this age group may prove useful, as these disorders are both characterized by a tendency to generate and fixate on threat-related future scenarios that may or may not materialize. Additionally, depression is associated with a reduced expectancy of positive future events. In this paper, we review the literature relevant to future thinking in anxiety and depression in older adults. We focus on the mental construction and anticipation of negative future events, and their underlying neurocognitive mechanisms. We then consider clinical and research implications of anxious and depressive future-oriented thought patterns for older adults. We believe that more research investigating future-oriented thought patterns associated with emotional disorders in later life could improve conceptualization, measurement, and perhaps potential treatments for late-life anxiety and depression.

Prenatal chronic mild stress induces depression-like behavior and sex-specific changes in regional glutamate receptor expression patterns in adult rats

Chronic stress during critical periods of human fetal brain development is associated with cognitive, behavioral, and mood disorders in later life. Altered glutamate receptor (GluR) expression has been implicated in the pathogenesis of stress-dependent disorders. To test whether prenatal chronic mild stress (PCMS) enhances offspring’s vulnerability to stress-induced behavioral and neurobiological abnormalities and if this enhanced vulnerability is sex-dependent, we measured depression-like behavior in the forced swimming test (FST) and regional changes in GluR subunit expression in PCMS-exposed adult male and female rats. Both male and female PCMS-exposed rats exhibited stronger depression-like behavior than controls. Males and females exhibited unique regional changes in GluR expression in response to PCMS alone, FST alone (CON-FST), and PCMS with FST (PCMS-FST). In females, PCMS alone did not alter N-methyl-d-aspartate receptor (NMDAR) or metabotropic glutamate receptor (mGluR) expression, while in PCMS males, higher mGluR2/3, mGluR5, and NR1 expression levels were observed in the prefrontal cortex. In addition, PCMS altered the change in GluR expression induced by acute stress (the FST test), and this too was sex-specific. Male PCMS-FST rats expressed significantly lower mGluR5 levels in the hippocampus, lower mGluR5, NR1, postsynaptic density protein (PSD)95, and higher mGluR2/3 in the prefrontal cortex, and higher mGluR5 and PSD95 in the amygdala than male CON-FST rats. Female PCMS-FST rats expressed lower NR1 in the hippocampus, lower NR2B and PSD95 in the prefrontal cortex, lower mGluR2/3 in the amygdala, and higher PSD95 in the amygdala than female CON-FST rats. PCMS may increase the offspring’s vulnerability to depression by altering sex-specific stress-induced changes in glutamatergic signaling.

Higher risk of developing major depression and bipolar disorder in later life among adolescents with asthma: A nationwide prospective study

ObjectivePrevious studies have suggested an immunological dysfunction in mood disorders, but rarely have investigated the temporal association between allergic diseases and mood disorders. Using the Taiwan National Health Insurance Research Database, we attempted to investigate the association between asthma in early adolescence and the risk of unipolar depression and bipolar disorder in later life. MethodsIn all, 1453 adolescents with asthma aged between 10 and 15 years and 5812 age-/gender-matched controls were selected in 1998–2000. Subjects with unipolar depression and bipolar disorder that occurred up to the end of follow-up (December 31 2010) were identified. ResultsAdolescents with asthma had a higher incidence of major depression (2.8% vs. 1.1%, p < 0.001), any depressive disorder (6.1% vs. 2.6%, p < 0.001), and bipolar disorder (1.0% vs. 0.3%, p < 0.001) than the control group. Cox regression analysis showed that asthma in early adolescence was associated with an increased risk of developing major depression (hazard ratio [HR]: 1.81, 95% confidence interval [CI]: 1.14–2.89), any depressive disorder (HR: 1.74, 95% CI: 1.27–2.37), and bipolar disorder (HR: 2.27, 95% CI: 1.01–5.07), after adjusting for demographic data and comorbid allergic diseases. DiscussionAdolescents with asthma had an elevated risk of developing mood disorders in later life. Further studies would be required to investigate the underlying mechanisms for this comorbid association and elucidate whether prompt intervention for asthma would decrease the risk of developing mood disorders.

Microstructural White Matter Changes in Geriatric Bipolar Disorder

The role of microstructural white matter changes impacting the clinical presentation of mood disorders in later life is increasingly recognized owing to advances in neuroimaging techniques. The newly developed diffusion MRI technique, Diffusion Kurtosis Imaging (DKI), is a clinically feasible and possibly more sensitive extension of the conventional diffusion tensor imaging (DTI). However, it has not been studied in the context of geriatric bipolar disorder (BD). In this study, we utilized DKI to assess its sensitivity in detecting microstructural changes in the brain in older adults with BD.

Does Childhood Asthma Increase the Risk of Mood Disorders in Later Life?

Problem statement: As a chronic condition, asthma may increase the risk of mood disorders. Understanding the association between asthma and mood disorders has important implications for asthma treatment and follow-up in primary care settings. Approach: To investigate whether asthma exposure during childhood is associated with the risk of mood disorders during adolescence and young adulthood, a population-based birth-cohort study of males born between 1980 and 1984 in Western Australia was conducted. Participants were identified using birth registry records and observed from age 12 years to December 31st, 2009 or death, whichever occurred first. Kaplan-Meier survival and Poisson regression analyses were performed to assess the effect of asthma exposure during childhood on the risk of mood disorders. Results: Hospitalization for asthma during childhood was found to be associated with an increased risk of mood disorders. Compared to participants without asthma admission before the age of 12, the relative risk of mood disorders was 1.32 (95% confidence interval 1.01-1.72) for those hospitalized once to twice for asthma and 1.66 (95% confidence interval 1.15-2.41) for those hospitalized three or more times for asthma, after controlling for potential confounding variables. Conclusion: The results supported the literature that asthma during childhood could increase the risk of mood disorders in later life. Prevention strategy should be developed to reduce the stress level among children with asthma to protect their normal mental development.

Effect of fish oil and coconut fat supplementation on depressive-type behavior and corticosterone levels of prenatally stressed male rats

Prenatal stress (PNS) during critical periods of brain development has been associated with numerous behavioral and/or mood disorders in later life. These outcomes may result from changes in the hypothalamic-pituitary-adrenal (HPA) axis activity, which, in turn, can be modulated by environmental factors, such as nutritional status. In this study, the adult male offspring of dams exposed to restraint stress during the last semester of pregnancy and fed different diets were evaluated for depressive-like behavior in the forced swimming test and for the corticosterone response to the test. Female Wistar rats were allocated to one of three groups: regular diet, diet supplemented with coconut fat or with fish oil, offered during pregnancy and lactation. When pregnancy was confirmed, they were distributed into control or stress groups. Stress consisted of restraint and bright light for 45min, three times per day, in the last week of pregnancy. The body weight of the adult offspring submitted to PNS was lower than that of controls. In the forced swimming test, time of immobility was reduced and swimming was increased in PNS rats fed fish oil and plasma corticosterone levels immediately after the forced swimming test were lower in PNS rats fed regular diet than their control counterparts; this response was reduced in control rats whose mothers were fed fish oil and coconut fat. The present results indicate that coconut fat and fish oil influenced behavioral and hormonal responses to the forced swimming test in both control and PNS adult male rats.

You are what you eat: of fish, fat and folate in late-life psychiatric disorders

There has been increasing research into the role of nutritional factors in mood and cognitive disorders in later life. This review evaluates findings from recent research for the role and effect of n-3 polyunsaturated fatty acids (PUFAs) and B vitamins in mood and cognitive disorders in later life. Epidemiological studies, including genetic epidemiological ones, continue to provide support for the role of folate and/or vitamin B12 in mood disorders in later life. However, evidence from recent randomized controlled trials for the effect of these B vitamins and n-3 PUFAs is modest. There is little robust evidence for the effect of these nutrients on cognitive disorders in later life. Larger randomized controlled trials allowing more appropriate meta-analyses are required to further evaluate current findings. Additionally, methods derived from research in geriatric medicine may assist in conceptualizing a role for these nutrients.

Prenatal stress in the rat alters 5-HT 1A receptor binding in the ventral hippocampus

Exposure of a pregnant woman to physical and/or psychological stress might affect her offspring by promoting the development of various learning, behavioral and/or mood disorders in later life. The 5-HT 1A and 5-HT 2A receptors are prominently implicated in the modulation of anxiety and mood-related behaviors. Using a semi-quantitative radiolabel immunocytochemical analysis (immunobinding), we studied the effect of prenatal stress on binding of these two receptor subtypes in the hippocampus of 4-week-old male and female Fischer 344 rats. Levels of 5-HT 1A immunobinding in the ventral hippocampus, which is primarily implicated in emotional processing, were significantly decreased in male offspring after prenatal stress. A trend towards a decrease was observed in the ventral hippocampus of females. In contrast, 5-HT 1A immunobinding within the dorsal hippocampus, which is mainly related to learning and memory, was not affected by prenatal stress in offspring of either gender. Likewise, no significant differences between control and prenatally stressed rats were observed for levels of 5-HT 2A immunobinding in either part of the hippocampus or gender. The observed reduction in hippocampal 5-HT 1A receptor binding in male offspring after prenatal stress may have important consequences for adult anxiety- and depressive-like behavior.

Prenatal Restraint Stress and Long-Term Affective Consequences

Chronic or repeated stress during critical periods of human fetal brain development has been associated with various learning, behavioral and/or mood disorders in later life. In this investigation, pregnant Fischer 344 rats was individually restrained three times a day for 45 min during the last week of gestation in transparent plastic cylinders while at the same time being exposed to bright light. Control pregnant females were left undisturbed in their home cages. Anxiety and depressive-like behavior was measured in the offspring at an age of 6 months using the open field test, the home cage emergence test and the forced swim test. Prenatally stressed rats spent more time in the corners and less time along the walls of an open field, while no difference in total distance moved was observed. In addition, prenatally stressed rats took more time to leave their home cage in the home cage emergence test. On the other hand, no differences in immobility were observed in the forced swim test. Moreover, prenatally stressed rats showed lower stress-induced plasma corticosterone levels compared with control rats. Prenatal stress (PS) had no effect on the number of 5-bromo-2-deoxyuridine-positive cells – used as a measure for cell proliferation – in the dentate gyrus of these rats. These data further support the idea that PS may perturb normal anxiety-related development. However, the present data also suggest that an adaptive or protective effect of PS should not be ignored. Genetic factors are likely to play a role in this respect.

The Complexity and Challenge of Non-Major Depression in Late Life

For the most part, research on mood disorders in later life has focused on major depression. It is well known, however, that much of the depressive symptomatology in older people is not captured by this construct. 1 Blazer DG Epidemiology of late-life depression. in: Schneider LS Reynolds CF Lebowitz BD Diagnosis and Treatment of Depression in Late Life. American Psychiatric Press, Washington, DC1994: 9-19 Google Scholar In part, this is because symptoms are of insufficient number or too intermittent to qualify for the diagnosis. 2 Lyness JM King DA Cox C et al. The importance of subsyndromal depression in older primary care patients: prevalence and associated functional disability. J Am Geriatr Soc. 1999; 47: 647-652 Google Scholar However, it also reflects the fact that criteria for Major Depression in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) 3 American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders. 4th Edition. American Psychiatric Association, Washington, DC1994 Google Scholar do not capture the phenotypic heterogeneity of depression in later life. 4 Caine ED Lyness JM King DA et al. Clinical and etiological heterogeneity of mood disorders in elderly patients. in: Schneider LS Reynolds CF Lebowitz BD Diagnosis and Treatment of Depression in Late Life. American Psychiatric Press, Washington, DC1994: 23-53 Google Scholar , 5 Gallo JJ Rabins PV Anthony JC Sadness in older persons: 13-year follow-up of a community sample in Baltimore, Maryland. Psychol Med. 1999; 29: 341-350 Google Scholar