From the Guidelines
Reduced volume of the hippocampus is a significant indicator of various neurological and psychiatric conditions, and addressing the underlying cause through a comprehensive approach that includes medications, cognitive behavioral therapy, lifestyle modifications, and nutritional support is crucial for promoting hippocampal neurogenesis and potentially reversing volume loss. This reduction in hippocampal volume is associated with conditions such as depression, post-traumatic stress disorder, Alzheimer's disease, and chronic stress exposure, as highlighted in a review of timely and accurate diagnosis of symptomatic Alzheimer's disease 1. The hippocampus plays a critical role in memory formation, emotional regulation, and spatial navigation, and its atrophy or decreased neurogenesis can have significant implications for an individual's quality of life.
Key factors that contribute to reduced hippocampal volume include:
- Chronic stress exposure
- Neuroinflammation
- Decreased brain-derived neurotrophic factor (BDNF) levels
- Implicated in various neurological and psychiatric conditions, including depression, post-traumatic stress disorder, and Alzheimer's disease Treatment approaches should focus on addressing the primary condition through:
- Medications, such as SSRIs for depression
- Cognitive behavioral therapy
- Lifestyle modifications, including regular aerobic exercise, adequate sleep, and cognitive stimulation
- Nutritional support through a Mediterranean diet rich in omega-3 fatty acids, antioxidants, and B vitamins
- Stress management practices, such as meditation, to reduce stress hormones like cortisol and promote growth factors like BDNF
Recent studies have highlighted the importance of considering the role of neuroinflammation and BDNF in the development and maintenance of chronic pain conditions, which can also impact hippocampal volume 1. Additionally, changes in brain structure, including reduced hippocampal volume, have been observed in individuals with obsessive-compulsive disorder (OCD), particularly those with comorbid depression 1. A comprehensive and multidisciplinary approach is essential for addressing reduced hippocampal volume and promoting overall brain health, with a focus on reducing morbidity, mortality, and improving quality of life.
From the Research
Reduced Volume of the Hippocampus
The reduced volume of the hippocampus is associated with various neurodegenerative and psychiatric diseases. Several studies have investigated the relationship between modifiable risk factors and hippocampal volume.
- A study published in 2015 2 found that smaller hippocampal volumes were strongly associated with poorer verbal learning and memory, as well as diagnoses of either multiple or amnestic mild cognitive impairment.
- The study also identified poor sleep efficiency, untreated depressive illness, diabetes, and low diastolic blood pressure as predictors of reduced hippocampal volumes.
- Another study published in 2021 3 found that exercise training has a positive effect on hippocampal volume, particularly in older samples and in interventions that lasted over 24 weeks.
- A study published in 2023 4 found that lower bilateral hippocampi and amygdalae volumes predicted worse treatment outcomes in patients with major depressive disorder.
Modifiable Risk Factors
Several modifiable risk factors have been identified as contributing to reduced hippocampal volume, including:
- Poor sleep efficiency 2
- Untreated depressive illness 2
- Diabetes 2
- Low diastolic blood pressure 2
- Lack of exercise 3
Treatment and Intervention
Various treatments and interventions have been studied to preserve or improve hippocampal volume, including: