If two devout Catholics marry, and at the time of their marriage truly intend all the elements of marriage, i.e. to be open to children, to be committed only to each other and to be committed to each other to unto death, and afterwards, one contracts and is diagnosed with a mental illness, is the marriage subject to a declaration of nullity on the grounds of the subsequent mental illness?
Marriages are declared null if an essential element is proven to have been absent at the time of the wedding—not subsequent to it. “In sickness and in health” still applies. The vows mean something.
Fr. Vincent Serpa, O.P.