as changes in personality. In addition, she states that approximately three in one thousand new mothers may experience more severe symptoms of PPD referred to as postpartum psychosis. Symptoms of this psychosis may include hallucinations, thoughts of suicide, and even thoughts of killing their newborn child. Dalton suggested using progesterone therapy to prevent this from happening, usually starting after the end of labour. Her proposed therapy was intended to help slow the speed at which the progesterone hormone naturally drops. Katharina Dalton published many books including: The Menstrual Cycle (1969); Premenstrual Syndrome and Progesterone Therapy (1977); Once a Month: The Original Premenstrual Syndrome Handbook (1978), which became a best seller, and Depression after Childbirth: How to Recognize, Treat, and Prevent Postnatal Depression. Personal life After the death of her first husband, Dalton married Tom Dalton, who died in 1992. She had four children, Michael, Thomas, Wendy, and Maureen. Dalton also had five grandchildren, including the British MEP Daniel Dalton. On 17 September 2004, Dalton died in Poole at the age of 87. References External links The Times' obituary: Dr Katharina Dalton NY Times obituary for Dr. Katharina Dalton Los Angeles Times obituary for Dr. Katharina Dalton "In Memory: Dr. Katharina Dalton" "PMS Researcher Dies at 87" 1916 births 2004 deaths 20th-century British medical doctors English medical writers Women medical writers Place of birth missing Place of death missing English women medical doctors 20th-century women physicians 20th-century British women writers 20th-century English women 20th-century English people