Science

...these researchers are figuring out the mechanism by which all these different disorders can show up in varying combinations in members of the same family. That is something new.

For example, my family tree includes a woman with schizoaffective disorder (schizophrenia combined with a mood disorder) who has a daughter with bipolar disorder and another one with major depressive disorder, but neither daughter is schizophrenic. That never made sense to me until now.