Slidell LAMedical Psychologist / Clinical Psychologist at Ps... Dr. Witt has practiced in St. Tammany Parish since 1991. From 1991-2005, her office was in Covington. More recently, Dr. Witt has joined a group of... Dr. Witt has practiced in St. Tammany Parish since 1991. From 1991-2005, her office was in Covington. More recently, Dr. Witt has joined a group of psychologists and psychotherapists in Slidell, LA. She is the prescriber for the group. All members of the group, including Dr. Witt, provide...