A person suspected of having unipolar depression has a smaller-than-usual hippocampus, although it produces a typical number of new neurons. This is:
typical.
unusual; individuals with unipolar depression usually have a smaller-than-usual hippocampus, causing it to produce a low number of new neurons.
unusual; individuals with unipolar depression usually have a typical-sized hippocampus, causing it to produce a low number of new neurons.
very unusual; individuals with unipolar depression usually have a typical-sized hippocampus, causing it to produce a typical number of new neurons.