Danish researchers have postulated that first-time mothers are at increased risk for mental disorders while fathers do not share that risk. The research is based on 32-year-old study that included more than 2.3 million Danes, nearly one in 1000 first time mothers were admitted to a psychiatric hospital with a mental illness such as depression, schizophrenia or bipolar disorder within the first three months. Mothers were four times more likely than women without children to be hospitalized with a mental illness. Amongst fathers, only 0.37 of 1,000 births resulted in a mental disorder, which was comparable to men without children or men with an older infant. Study’s author Trine Munk-Olsen said, ‘This may indicate that the causes of postpartum mental disorders are more strongly linked to an altered physiological process related to pregnancy and childbirth than psychosocial aspects of motherhood’. The report proposed that a woman’s hormones before and after birth are responsible for the changes.