Brain shrinkage

Reduction in brain size

Neurotrauma, brain damage or brain injury (BI) is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors. In general, brain damage refers to significant, undiscriminating trauma-induced damage.

A common category with the greatest number of injuries is traumatic brain injury (TBI) following physical trauma or head injury from an outside source, and the term acquired brain injury (ABI) is used in appropriate circles to differentiate brain injuries occurring after birth from injury, from a genetic disorder (GBI), or from a congenital disorder (CBI). Primary and secondary brain injuries identify the processes involved, while focal and diffuse brain injury describe the severity and localization.

Recent research has demonstrated that neuroplasticity, which allows the brain to reorganize itself by forming new neural connections throughout life, provides for rearrangement of its workings. This allows the brain to compensate for injury and disease.

Source: Wikipedia

The hippocampus shrinks by 8% following traumatic emotional stress, and this may reduce memory and learning capacity. The shrinkage was much worse, 22% to 26%, in veterans who were involved in more intense combat and had more severe post traumatic stress disorder symptoms.
Perhaps the hippocampus does not shrink; it's just that people with a smaller hippocampus are more likely to show symptoms of emotional trauma.
(G) Very specific problems