PMS is a psycho-neuro-endocrinal disorder of unknown etiology, often noticed just prior to menstruation . There is a cyclic reappearance of a large number of symptoms during the last 7-10 days of menstrual cycle which are not caused by any organic disease.
Various studies have shown appearance of significant behavioral symptoms - depression, aggression, agitated depression and other symptoms like irritability etc. during PMS. The nature of behavioral changes or symptoms, which perhaps are the focus of the link with criminal law, has been studied for about 30 years. Some research focuses on the fact that the menstrual cycle is in itself influenced by stress to such a large extent and thus that the relationship between behavioral changes and premenstrual changes is complex and multidirectional . One such study in the United States of America observed that 79% of women report experiencing emotional changes such as mood swings, irritability, anger and depression when they have PMS. And men are perceptive when it comes to PMS and its effect on women in their lives - 84% of men report that women are close to experience the emotional changes of PMS .
As per this study, women believe that their personal relationship suffer the most as a result of the emotional changes of PMS. The survey shows that 72% of women feel that PMS negatively affects their relationship with their husbands/significant others and 62% of them feel it negatively affects their relationship with their children . Dalton (1959) found that 46% of all admissions in psychiatry ward and 53% of attempted suicides were during menstruation or pre-menstruation .
A strong relationship between psychiatric illness especially depression and severity of PMS was confirmed . In a study of prison inmates it was found that out of a group of 42 women who had committed crimes of violence, the crime of 25 (62%) of women had taken place in pre-menstruating and one at the end of menstrual phase .