“The sacrament of Matrimony establishes a perpetual and exclusive bond between the spouses. God himself seals the consent of the spouses. Therefore, a marriage which is ratified and consummated between baptized persons can never be dissolved” (CCCC 346).
BITE-SIZE THEOLOGY (159) What deficiencies in knowledge and consent can affect the marriage?
Since free consent depends on an act of the intellect and the will (cf CCC 1731), we can say that anything that either diminishes (1) the knowledge required or (2) the exercise of the will negatively affects the consent.