showed that during times of severe PMS, students' academic performance dipped and women were more likely to abuse their children or commit crimes. From historic anecdotes, she even concluded that Queen Victoria suffered from PMS, as indicated by reports of her monthly screaming and throwing objects at her husband, Prince Albert. She is largely credited with developing the use of menstrual charts for the diagnosis of the disorder, and argued that the timing of PMS in women was associated with higher rates of suicide attempts, alcohol abuse and violent crimes. PMS, Dalton argued, was brought on primarily by deficiencies of progesterone and could be alleviated with hormone therapy. She also believed that the hormone could be used to ease postnatal depression. But today most experts disagree with those findings and instead rely on selective serotonin reuptake inhibitors (SSRI) and other medications for the treatment of PMS. In her later works, Dalton helped demonstrate that depression and other disorders could be aggravated by PMS, particularly around the last few days of the menstrual cycle or the first days of menstruation. Dalton eventually became the first female president of the general practice section within the Royal Society of Medicine. Another observation made by Dalton was that some symptoms of PMS, such as hypertension, edema, and albumin in the urine, were predictors of toxaemia during pregnancy. Patients were administered an initial dose of progesterone during early symptoms and given continuous treatment if symptoms were still present. Using progesterone in trials in maternity hospitals, the incidence rate of toxemia dropped from 9 percent to 1 percent. Dalton refused use of progestins (synthetic progestogens) in treatment as she believed they were the cause of side effects. She preferred bio-identical, or natural progesterone. In addition, Dalton only supported the use of natural progesterone as she claims that only natural progesterone fit progesterone receptors. Most of her treatments used generous doses of progesterone as she believed that there was no unsafe dose, with 400 milligrams via suppository being the minimum dose. Other positive effects of progesterone include increased hair growth and treatment of brain trauma. After her work on PMS, she turned to postpartum depression (PPD). The large drop in hormone levels after giving birth can cause new mothers to feel symptoms of tiredness, irritability, and depression, similar to PMS. According to Dalton, these symptoms are considered mild, whereas more severe symptoms can include anxiety as well