As early as 1400 BCE, the Roman natural historian Pliny wrote of using black hellebore for mental conditions. Ancient Greek and Roman philosophers would drink an infusion of the plant to increase their concentration before prolonged debates. The herb is extremely toxic and is now used only in homeopathy, since herbalists believe that it is too strong to be used safely. Helleborus was proved by Hahnemann and published in his Materia Medica Pura (1821-34). The people who benefit most from taking this remedy are characteristically dull and sluggish. Helleborus is best suited to those who feel stupefied and have slow mental processes. They commonly experience anguish, irritability, apathy, and depression. These people frequently feel as though their brains are in turmoil, and do not understand what is going on around them. Although they may beg for help, they are generally inconsolable. Physical symptoms generally worsen between 4 p.m. and 8 p.m., and improve in warmth and when lying covered up. Helleborus is prescribed for mental states that feature sluggishness and stupefaction. Acute inflammatory nervous conditions may be helped, as may headaches, digestive problems, and depression. Symptoms may follow as a result of concussion, surgery to the brain, or a bout of meningitis or encephalitis. Nervous-system disorders - stupefaction and dullness, possibly even giving an impression of stupidity or mental disorder. Questions are answered slowly and with great effort. The body feels numb and the brain loses control over the muscles, so that objects drop easily from the hands. Forgetfulness and poor concentration, with the memory becoming totally blank, are common. In extreme cases symptoms may be associated with Alzheimer's disease, including memory loss, anxiety, and disorientation. Brain inflammation - swelling of the brain tissue, possibly caused by encephalitis or meningitis. Symptoms typically include convulsions, and the head tends to feel very hot while the body feels very cold. There is a feeling of stupor and sluggishness. Headaches - a headache or migraine with mental dullness, possibly after injury or surgery. The headache often begins in the back of the head or in the neck, and there may be a need to pull the head down toward the body. Dizziness and vertigo causing vomiting may accompany the pain. Digestive disorders - painful bowel urges with watery diarrhea and mucus. Bowel movements are so disoriented and sluggish that constipation may also occur. There is often a lack of thirst and a dry mouth. Depression - blank stares, involuntary sighs, and dark moods, especially between 4 p.m. and 8 p.m. The lips and clothes may be picked at.