Amygdala and hippocampus volumes in pediatric major depression

The biochemistry of dysfunctional emotions: proton MR spectroscopic findings in major depressive disorder

Key neural systems involved in the processing and communication of emotions are impaired in patients with major depressive disorder (MDD). Emotional and behavioral symptoms are thought to be caused by damage or dysfunction in specific areas of the brain that are responsible for directing attention, motivating behavior, and learning the significance of environmental stimuli. Functional brain studies with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) give support for functional abnormalities in MDD that are predominantly located in areas known to play an important role in the communication and processing of emotions. Disturbances in emotional processing as they are observed in MDD, if any, have very subtle morphometrical brain correlates. With proton magnetic resonance spectroscopy (1H MRS), brain metabolites can be measured noninvasively in vivo, thus furthering the understanding of the effects of changes in neurotransmitters within the brain. The current literature on 1H MRS studies in MDD is small with a large diversity of MRS methods applied, brain regions studied, and metabolite changes found. Nevertheless, there is strong evidence that changes in neurometabolite concentrations in MDD occur within brain regions, which are involved in the processing and communication of emotions that can be monitored by 1H MRS. This review summarizes the literature about biochemical changes quantified via 1H MRS in MDD patients in brain regions that play an important role for the communication and processing of emotions.

An update on regional brain volume differences associated with mood disorders

PURPOSE OF REVIEW

Structural brain changes are apparent in some magnetic resonance imaging studies of patients with mood disorders, but results are inconsistent. The focus of this review is to examine whether there are demographic or clinical characteristics of people with mood disorders that are associated with regional brain volume changes. A systematic search of the literature in English, from January 2004 to July 2005, was performed on MEDLINE. References cited in all reports were searched iteratively to identify missing studies.

RECENT FINDINGS

Recent studies have focused on factors that might help to reconcile the divergent reports of regional brain volume changes in major depressive disorder and bipolar disorder. Small hippocampal volumes are apparent in patients with recurrent major depressive disorder, but not generally reported early in the course of adult onset depression. Small hippocampal volumes may be apparent in patients with childhood onset illness. Small hippocampal volumes are infrequently reported in bipolar disorder, but studies to date have not accounted for illness history or treatment status. Changes in amygdala volumes are inconsistently reported in patients with major depressive disorder or bipolar disorder. There are relatively fewer reports of other brain regions, including the areas of the frontal cortex and striatum. An extensive preclinical literature suggests that various psychotropic medications may have neurotrophic and neuroprotective effects, making documentation of treatment history essential.

SUMMARY

Patients' age, sex, age at onset of disease, course of illness and treatment status may affect the detection of regional brain volume changes in people with mood disorders.

Magnetic resonance spectroscopic studies of pediatric mood disorders: a selective review

PURPOSE OF REVIEW

This review article presents a summary of the recent magnetic resonance spectroscopic studies of pediatric mood disorders.

RECENT FINDINGS

Magnetic resonance imaging is a promising tool for investigating the biologic substrates of neuropsychiatric disorders without the use of ionizing radiation. This novel technique has been recently applied to pediatric patients with mood disorders. Structural, chemical, and functional abnormalities in pediatric patients with mood disorders have been reported.

SUMMARY

To date, only modest numbers of pediatric studies using magnetic resonance imaging have been conducted. Most of these studies have small sample sizes and heterogeneous subject groups. These studies have provided important information regarding the underlying neuro-circuitry and pathophysiology of these complex and disabling disorders, however.

Stress and depression in informal family caregivers of patients with Alzheimer’s disease

Family caregiving of older individuals with Alzheimer’s disease is becoming widespread in the USA and around the world because of the aging of the population. As a result, family members are increasingly being asked to perform complex tasks similar to those carried out by paid health or social service providers. Dementia caregiving presents unique and extreme challenges associated with caring for someone with cognitive and behavioral impairment. This article summarizes the extensive literature on dementia caregiving, identifies key issues and major findings regarding the definition and prevalence of caregiving, and reviews the epidemiological, cultural, individual and biological factors contributing to caregiver stress and depression. The author describes the psychiatric and physical health effects of caregiving and reviews various intervention approaches to improving caregiver burden, depression and quality of life. The author offers a perspective on future directions in dementia caregiver research and development of more effective interventions.