Theo was the source of stability and the intermediate between the two artists and allowed them to create prolifically for a couple of months (63 days) ; paintings we would otherwise have been deprived of. (Letter 852). The two brothers maintained an intensive correspondence, with Theo often encouraging his depressed brother. Theo was one of the few people who Vincent could talk to and confide in. These letters are one of the few sources of information about Vincent's life, providing detailed accounts of not only the occurrences but also the thoughts and feelings in Vincent's life. Over three-quarters of the more than 800 letters Vincent wrote during his life were to Theo, including his first and his last letters. It is largely thanks to Theo and his wife, Johanna, who, in 1914, decided to publish the letters between Theo and Vincent, that these letters are available to us today. Hardly any of Theo's letters remain because Vincent failed to keep them. It can also be noted that the two-year period where Vincent and Theo lived together in the neighborhood of Montmartre in Paris, is also the least documented period of Vincent's artistic career, because of the lack of letters exchanged between the two brothers. These letters witness both the emotional and professional state of Vincent throughout his life as early as 1874 and serve as a diary for his everyday encounters. The letters have been collected and published in book form as "The Letters of Vincent van Gogh". The relationship between the two brothers was the subject of the movie "Vincent & Theo" (1990), directed by Robert Altman. It also formed an important part of the film "Lust for Life" (1956), which was directed by Vincente Minnelli. Theo was played by the British actor James Donald and Vincent by the Hollywood star Kirk Douglas. The delivery of Vincent's final letter to Theo after Vincent's death and the circumstances surrounding his death was the subject of the 2017 film "Loving Vincent", which was animated by oil paintings made with Van Gogh's techniques. Theo's health deteriorated in the months after the death of his brother. He was admitted to the Willem Arntz Hospital, a psychiatric hospital, in Den Dolder on 18 November 1890. He had been diagnosed in Paris as suffering from a progressive and general paralysis. Initial examination confirmed this diagnosis. By 1 December his medical notes confirmed he presented all the symptoms of "dementia paralytica", a disease of the brain. He died on 25 January 1891.