This study aimed to compare the hippocampal volume of patients with combat-related posttraumatic stress disorder (PTSD) to that of healthy subjects using magnetic resonance imaging (MRI). The researchers hypothesized that PTSD patients would have a smaller right hippocampal volume and that this volume reduction would be associated with deficits in short-term verbal memory. **Methods:** - **Participants:** 26 Vietnam veterans with PTSD and 22 matched comparison subjects were recruited. - **MRI:** MRI images were acquired to measure the volume of the hippocampus, temporal lobe, and caudate. - **Data Analysis:** Repeated measures ANOVA and ANCOVA were used to compare volumes between groups, controlling for factors like age, sex, race, education, and alcohol abuse. **Results:** - PTSD patients had an 8% smaller right hippocampal volume compared to the comparison subjects. - There was no significant difference in left hippocampal volume or other brain regions between the two groups. - Deficits in short-term verbal memory, measured by the Wechsler Memory Scale, were associated with smaller right hippocampal volume in PTSD patients. - No significant correlation was found between verbal memory and other brain structures or visual memory and hippocampal volume. **Discussion:** - The findings suggest that PTSD is associated with a smaller right hippocampal volume, which may contribute to memory deficits. - The study also considered the effects of comorbid depression and alcohol/drug abuse but found no significant differences in hippocampal volume. - The results have implications for understanding the neurobiological basis of PTSD and potential treatment strategies. **Conclusion:** The study provides evidence that combat-related PTSD is associated with a specific brain structure, the hippocampus, which may play a role in memory deficits observed in PTSD patients.This study aimed to compare the hippocampal volume of patients with combat-related posttraumatic stress disorder (PTSD) to that of healthy subjects using magnetic resonance imaging (MRI). The researchers hypothesized that PTSD patients would have a smaller right hippocampal volume and that this volume reduction would be associated with deficits in short-term verbal memory. **Methods:** - **Participants:** 26 Vietnam veterans with PTSD and 22 matched comparison subjects were recruited. - **MRI:** MRI images were acquired to measure the volume of the hippocampus, temporal lobe, and caudate. - **Data Analysis:** Repeated measures ANOVA and ANCOVA were used to compare volumes between groups, controlling for factors like age, sex, race, education, and alcohol abuse. **Results:** - PTSD patients had an 8% smaller right hippocampal volume compared to the comparison subjects. - There was no significant difference in left hippocampal volume or other brain regions between the two groups. - Deficits in short-term verbal memory, measured by the Wechsler Memory Scale, were associated with smaller right hippocampal volume in PTSD patients. - No significant correlation was found between verbal memory and other brain structures or visual memory and hippocampal volume. **Discussion:** - The findings suggest that PTSD is associated with a smaller right hippocampal volume, which may contribute to memory deficits. - The study also considered the effects of comorbid depression and alcohol/drug abuse but found no significant differences in hippocampal volume. - The results have implications for understanding the neurobiological basis of PTSD and potential treatment strategies. **Conclusion:** The study provides evidence that combat-related PTSD is associated with a specific brain structure, the hippocampus, which may play a role in memory deficits observed in PTSD patients.