I thought it was a Clark Gable movie but cannot find any plot synopsis that matches. The male lead works, I think, at an advertising agency but it doesn't seem to match the Hucksters because the main plot elements are the problems in the relationship with his wife (she may start out as girlfriend or fiancee). By the end, it is discovered that her nervous breakdown/mental illness is due to previous abuse of some sort and he's going to get her professional help. I can't remember if the problems included frigidity or multiple personality but I do remember it dealt with psychoanalysis the same way current "problem of the month" movies bring them to the public's attention. I thought it was set in 1950's but could be earlier. Based on the clothing I remember, it was no later than early 60's (no flower child references).