I know these kind of brain morphometry analyses (I published an article using them). I would not trust the results too much. Those analyses are really straight-forward to setup once you have access to a MRI dataset, which makes them very popular. It can be easy to get a significantly positive result when you toy with the statistical thresholding techniques, especially with a rather low sample-size which is the case here with the sub-group "depression + child sex abuse".

Also it feels strange that the brain region specifically associated with child sex abuse would be in the occipital cortex, which is responsible for visual processing. The authors probably had to make mental gymnastics in the discussion to justify this piece of results.

I would wait for other studies to confirm this before having any opinion on this.