As far as Marian devotions go, this one is pretty obscure. As such, the origin is a little ambiguous. Some stories say it began with a holy priest who acted as a chaplain to patients in a psychiatric ward. What we know for sure is that this private devotion has been approved and blessed by St. Pope John XXIII and St. Pope Paul VI.
For at least a century, this devotion has brought hope to all those who experience mental illness and mental health challenges, assuring them that there is a place for them in the body of Christ and that mental illness is no obstacle to the sanctity which is God's life in us.
Just as Christ is always with the sick, the marginalized, the misunderstood, the forgotten and neglected, so He is with those who live with mental illness and particularly those who lack the care they need and deserve. They are under the motherly protection of Our Lady and when they are rejected she personally ushers them to the wounded side of the crucified Christ.
Cardinal Cushing, an advocate of this devotion, said, "If Christ and His Blessed Mother were on earth today, he would spend much time among the mentally ill."
You can find the prayer to Our Lady of Mental Peace here.
As a child, St. Therese suffered from anxiety, OCD, and hallucinations. She also may have experienced symptoms of bipolar disorder or schizophrenia. Her symptoms were severe enough that she had to be taken out of school, and when she returned she struggled to socialize with the other children. While praying before a statue of the Blessed Virgin with her sisters, Thérèse was miraculously cured, and she went on to enter Carmel along with several of her biological sisters. While at Carmel, she developed her spirituality of the Little Way, and she died of tuberculosis at age 24. She was later declared a Doctor of the Church.
Father to St. Thérèse and husband to St. Zélie Martin, St. Louis began experiencing symptoms of mental illness after his youngest daughter Thérèse entered the convent. He suffered symptoms of depression, anxiety, paranoia, and dementia. When he was committed to an asylum, many people in their small town mocked him and spread unkind rumors about him and his family. But St. Louis said about this, "I have never had any humiliations in my life, and I needed to have some."
Born in Dublin to a Catholic family with 12 children, Matt began drinking in adolescence, a habit which quickly developed into an addiction. At his worst, he resorted to selling his clothes and shoes and even stealing to support his addiction. After getting sober in his late twenties, he abstained from alcohol for the remaining 41 years of his life and dedicated his life to living in solidarity with the poor.
Known as the "Beggar of Rome", Benedict lived most of his life homeless. Though he ardently desired to join religious life, he was rejected by three religious orders due to his mental disturbances. Though it is unclear what disorder he suffered from, he was known for eccentric and erratic behavior. He eventually joined the Third Order of Saint Francis and discerned that his vocation was to serve God exactly where he was-- on the streets. He was deeply devoted to the Blessed Sacrament and was familiar with many clergy members who lived in Rome. After his death, one of the clergy who knew him said of him, "He had only half a mind, but he gave it all to God." He is now the patron saint of those experiencing mental illness, homelessness, and societal rejection.
Due to his opium addiction, St. Mark Ji Tianxiang was barred from the sacraments for the last 30 years of his life. Because addiction was not understood as a legitimate disorder requiring treatment, his confessor interpreted Mark's addiction as mortally sinful and scandalous. Barred from the sacraments, Mark continued to serve God and struggle with his addiction until the day he was martyred with several other men from his Chinese village.
Born to a wealthy Spanish family, Teresa was one of the great reformers of the Carmelite Order during the Counter-Reformation. Her reforms brought her under attack by the Spanish Inquisition, but ultimately no charges were made against her. Teresa suffered from physical sickness and depression for many years during her adult life, and she advised spiritual directors against mistaking emotional disturbances for spiritual weakness. Though she devoutly followed the mortifications of her religious order, she also had great understanding of the material needs of the body, advising gloom sisters to eat steak to lift their spirits. She was declared a Doctor of the Church four centuries after her death.
Born in modern-day Sudan, Josephine was the niece of the chief of her tribe and lived a carefree life. When she was about 8 years old, she was abducted by slave traders, an experience so traumatic to her that she forgot her birth name (this is known today as dissociative amnesia). The slave traders named her "Bakhita", meaning "Lucky". She suffered under the ownership of a cruel mistress who "tattooed" Josephine along with her other slaves (these tattoos were made by carving images into the skin with a blade, often covering the whole body including breasts). After being traded, she eventually found herself in Italy, where the law did not recognize slavery. She left her mistress to live with a community of Canossian sisters, where she eventually made vows as a religious herself. Josephine was known to suffer from nightmares and flashbacks, particularly as she was nearing death, during which she would beg her fellow sisters to loosen her chains. She suffered many symptoms of trauma throughout her life; she is the patron of survivors of human trafficking and has also been suggested as a possible patron for those who suffer from self-harm. Soon before her death, her flashbacks ceased and when a sister asked her how she was, she responded, "Yes, I am so happy. Our Lady... Our Lady!" These were her last words. She was canonized in 2000 by St. Pope John Paul II.
Daughter of the famed author Nathaniel Hawthorne, Rose Hawthorne suffered from postpartum depression after the birth of her son Francis. When Francis died only a few years later, her husband George developed a dependency on alcohol, a situation which eventually caused Rose to fear for her safety. She sought permission from the bishop to live separately from her husband, and this permission was granted.While living apart from George, Rose learned about poor cancer patients who were being sent away to die alone in poverty (cancer was believed to be contagious at the time). Moved by the indignity of their suffering, she took a nursing course in order to be able to serve them. After the death of her husband, she felt called to turn her mission into a religious congregation. Though this was initially challenging due to people's hesitancy to come into contact with cancer patients, her small congregation slowly began to grow. She continued to serve alongside her sisters until her death in 1926. The Dominican Sisters of Hawthorne still serve terminally ill cancer patient in New York to this day.
Oscar Romero, known today for his ministry to the poor and marginalized in El Salvador, entered the seminary when he was just 13-years-old. Committed to the priesthood and service of his people, he became exhausted from his work and took a retreat in 1996 during which a psychiatrist diagnosed him with Obsessive-Compulsive Personality Disorder. While receiving therapy for his condition, he continued his service as a priest and archbishop until he was assassinated in 1980.
St. Dymphna did not suffer from mental illness herself, as far as we know, but her father suffered a breakdown after the death of Dymphna's mother. When he tried to marry his daughter, Dymphna fled to Belgium with her confessor. Her father eventually tracked her down and killed her. She is the patron saint of those who suffer from mental and emotional disturbances, incest victims, and mental health professionals.
St. Benedict Menni was the founder of the Sister Hospitallers of the Sacred Heart of Jesus, a religious order dedicated to caring for the mentally ill, intellectually disabled, and other disabled populations. Benedict felt called to form this new order after observing the neglect and mistreatment of the mentally ill in Spain. In response, he founded a psychiatric hospital where he firmly rejected any corporal punishment toward the mentally ill (a groundbreaking decision for his time). Instead, he invited women religious to care for them with gentleness and understanding. He founded a total of twelve psychiatric hospitals in his lifetime. Today, the Sister Hospitallers serve in Europe, Latin America, and Africa.