I am not totally sure if you mean with catastrophic phobia, that someone has the tendency to exaggerate fear and bad happenings? If so, (but with caution, because I do not know enough about the person) I wold rather encourage mindfulness techniques. Introspection like in "exploring one’s feelings and thoughts" could augment bad thinking patterns (like catastrophizing), mindfulness techniques would more encourage to not explore but notice the thoughts and feelings (without further exploring, but an accepting mindset). But as said above, I am not sure, if you perhaps meant the same :-D
And thank you for the blueberry tip, sadly no blueberries here … only some weeks in summer