(1) Intermarriage by persons within the prohibited degrees of consanguinity or affinity;

(2) Mental incapacity at the time of the marriage;

(3) Impotency at the time of the marriage;

(4) Force, menace, duress, or fraud in obtaining the marriage;

(5) Pregnancy of the wife by a man other than the husband, at the time of the marriage, unknown to the husband;

(6) Adultery in either of the parties after marriage;

(7) Willful and continued desertion by either of the parties for the term of one year;

(8) The conviction of either party for an offense involving moral turpitude, under which he is sentenced to imprisonment in a penal institution for a term of two years or longer;

(9) Habitual intoxication;

(10) Cruel treatment, which shall consist of the willful infliction of pain, bodily or mental, upon the complaining party, such as reasonably justifies apprehension of danger to life, limb, or health;

(11) Incurable mental illness. No divorce shall be granted upon this ground unless the mentally ill party has been adjudged mentally ill by a court of competent jurisdiction or has been certified to be mentally ill by two physicians who have personally examined the party; and he has been confined in an institution for the mentally ill or has been under continuous treatment for mental illness for a period of at least two years immediately preceding the commencement of the action; and the superintendent or other chief executive officer of the institution and one competent physician appointed by the court, after a thorough examination, make a certified statement under oath that it is their opinion that the party evidences such a want of reason, memory, and intelligence as to prevent the party from comprehending the nature, duties, and consequences of the marriage relationship and that, in the light of present day medical knowledge, recovery of the party's mental health cannot be expected at any time during his life. Notice of the action must be served upon the guardian of the person of the mentally ill person and upon the superintendent or other chief executive officer of the institution in which the person is confined. In the event that there is no guardian of the person, then notice of the action shall be served upon a guardian ad litem, who shall be appointed by the court in which the divorce action is filed, and upon the superintendent or chief executive officer of the institution in which the person is confined. The guardian and superintendent shall be entitled to appear and be heard upon the issues. The status of the parties as to the support and maintenance of the mentally ill person shall not be altered in any way by the granting of the divorce;

(12) Habitual drug addiction, which shall consist of addiction to any controlled substance as defined in Article 2 of Chapter 13 of Title 16; or

(13) The marriage is irretrievably broken. Under no circumstances shall the court grant a divorce on this ground until not less than 30 days from the date of service on the respondent.