The voluntary limitation of the family is as old as the human race.The practice is universal.It is the inalienable right of every couple to regulate the size of their family if they wish. They do it anyway.Most contraceptives in general use are unsatisfactory, if not out-and-out unsafe, because (a) they do not always prevent a pregnancy; (b) they interfere with complete gratification and thus are apt to produce a neurosis indirectly; (c) either by inducing a delay in period due to anxiety or by an actual conception they expose the woman to the unnecessary risk and expense of an abortion. They lead to marital unhappiness, discord in the home, or even broken homes. Children in such homes have little chance to escape a neurosis.It behooves us as physicians and psychiatrists to find an efficient, simple and unobjectionable method of contraception and make it available to our patients as a mental hygiene measure.The rubber diaphragm, or cervical cap, as advocated by the American Birth Control League, has proved simple, efficacious and conducive to a normal sex relation; and although some claim only 93 per cent success, it has proved 100 per cent successful in this present series of cases. Any failures reported were due to lack of cooperation on the part of husband or wife, and not inherent in the method.In 400 cases we found only 10 husbands who objected to the use of the diaphragm. From experience with patients who use it without knowledge of their husbands, we know the objection is based on an imagined interference with their pleasure, and not a real one.Women who have always experienced an orgasm express themselves as much happier since using the diaphragm.In our series of 400 cases, improved contraceptive methods have produced a definite return or improvement in orgasm in 28 per cent of the cases, with a consequent improvement in general health and mood, and a happier outlook on life. Even when there is no return of orgasm, the elimination of fear—the security—affords them serenity and contentment.Many women have been saved the physical, financial and emotional strain of an unnecessary abortion.Because it does remove unnecessary worry and relieves unnecessary tension, it makes for a more harmonious relationship between husband and wife, and a better home for the children.It is not our intention to suggest birth control as a cure-all, but we do maintain that it is a very important adjunct to the armamentarium of every physician, especially psychiatrists, to relieve anxiety, so that the energy thus wasted may be utilized in the service of psychotherapy.Our interest in birth control was born out of a desire to help our patients, little suspecting at first any deep psychological significance in connection with it. We had no preconceived notions either for or against its claims. Whatever of interest we found in this work was not a planned attempt at research. The facts were there all the time clamoring for expression. We are merely reporting what we saw over and over again for the past nine years.We believe this subject merits further study and the serious interest of psychiatrists. As a mental hygiene measure, it is one of the finest and soundest investments we can make.