Both Charles and his sister Mary suffered a period of mental illness.
As he himself confessed in a letter, Charles spent six weeks in a mental facility during 1795:
Coleridge, I know not what suffering scenes you have gone through at Bristol.
My life has been somewhat diversified of late.
The six weeks that finished last year and began this your very humble servant spent very agreeably in a mad house at Hoxton—I am got somewhat rational now, and don't bite any one.
But mad I was—and many a vagary my imagination played with me, enough to make a volume if all told.
My Sonnets I have extended to the number of nine since I saw you, and will some day communicate to you.

— Lamb to Coleridge; 27 May 1796.

However, Mary Lamb's illness was particularly strong, and it led her to become aggressive on a fatal occasion.
On 22 September 1796, while preparing dinner, Mary became angry with her apprentice, roughly shoving the little girl out of her way and pushing her into another room.
Her mother, Elizabeth, began yelling at her for this, and Mary suffered a mental breakdown as her mother continued yelling at her.
Mary took the kitchen knife she had been holding, unsheathed it, and approached her mother, who was sitting down.
Mary, "worn down to a state of extreme nervous misery by attention to needlework by day and to her mother at night", was seized with acute mania and stabbed her mother in the heart with a table knife.
Charles ran into the house soon after the murder and took the knife out of Mary's hand.

Later in the evening, Charles found a local place for Mary in a private mental facility called Fisher House, which had been found with the help of a doctor friend of his.
While reports were published by the media, Charles wrote a letter to Samuel Taylor Coleridge in connection to the matricide:
MY dearest friend – White or some of my friends or the public papers by this time may have informed you of the terrible calamities that have fallen on our family.
I will only give you the outlines.
My poor dear dearest sister in a fit of insanity has been the death of her own mother.
I was at hand only time enough to snatch the knife out of her grasp.
She is at present in a mad house, from whence I fear she must be moved to an hospital.
God has preserved to me my senses, – I eat and drink and sleep, and have my judgment I believe very sound.
My poor father was slightly wounded, and I am left to take care of him and my aunt.
Mr Norris of the Bluecoat school has been very very kind to us, and we have no other friend, but thank God I am very calm and composed, and able to do the best that remains to do.
Write, —as religious a letter as possible— but no mention of what is gone and done with. —
With me "the former things are passed away," and I have something more to do that [than] to feel.
God almighty have us all in his keeping.

— Lamb to Coleridge.
27 September 1796
Charles took over responsibility for Mary after refusing his brother John's suggestion that they have her committed to a public lunatic asylum.
Lamb used a large part of his relatively meagre income to keep his beloved sister in the private "madhouse" in Islington.
With the help of friends, Lamb succeeded in obtaining his sister's release from what would otherwise have been lifelong imprisonment.
Although there was no legal status of "insanity" at the time, the jury returned the verdict of "lunacy" which was how she was freed from guilt of willful murder, on the condition that Charles take personal responsibility for her safekeeping.

The 1799 death of John Lamb was something of a relief to Charles because his father had been mentally incapacitated for a number of years since suffering a stroke.
The death of his father also meant that Mary could come to live again with him in Pentonville, and in 1800 they set up a shared home at Mitre Court Buildings in the Temple, where they would live until 1809.

In 1800, Mary's illness came back and Charles had to take her back again to the asylum, probably Bethlehem Hospital.
In those days, Charles sent a letter to Coleridge, in which he admitte
Both Charles and his sister Mary suffered a period of mental illness. As he himself confessed in a letter, Charles spent six weeks in a mental facility during 1795:
Coleridge, I know not what suffering scenes you have gone through at Bristol. My life has been somewhat diversified of late. The six weeks that finished last year and began this your very humble servant spent very agreeably in a mad house at Hoxton—I am got somewhat rational now, and don't bite any one. But mad I was—and many a vagary my imagination played with me, enough to make a volume if all told. My Sonnets I have extended to the number of nine since I saw you, and will some day communicate to you.
— Lamb to Coleridge; 27 May 1796.
However, Mary Lamb's illness was particularly strong, and it led her to become aggressive on a fatal occasion. On 22 September 1796, while preparing dinner, Mary became angry with her apprentice, roughly shoving the little girl out of her way and pushing her into another room. Her mother, Elizabeth, began yelling at her for this, and Mary suffered a mental breakdown as her mother continued yelling at her. Mary took the kitchen knife she had been holding, unsheathed it, and approached her mother, who was sitting down. Mary, "worn down to a state of extreme nervous misery by attention to needlework by day and to her mother at night", was seized with acute mania and stabbed her mother in the heart with a table knife. Charles ran into the house soon after the murder and took the knife out of Mary's hand.
Later in the evening, Charles found a local place for Mary in a private mental facility called Fisher House, which had been found with the help of a doctor friend of his. While reports were published by the media, Charles wrote a letter to Samuel Taylor Coleridge in connection to the matricide:
MY dearest friend – White or some of my friends or the public papers by this time may have informed you of the terrible calamities that have fallen on our family. I will only give you the outlines. My poor dear dearest sister in a fit of insanity has been the death of her own mother. I was at hand only time enough to snatch the knife out of her grasp. She is at present in a mad house, from whence I fear she must be moved to an hospital. God has preserved to me my senses, – I eat and drink and sleep, and have my judgment I believe very sound. My poor father was slightly wounded, and I am left to take care of him and my aunt. Mr Norris of the Bluecoat school has been very very kind to us, and we have no other friend, but thank God I am very calm and composed, and able to do the best that remains to do. Write, —as religious a letter as possible— but no mention of what is gone and done with. —With me "the former things are passed away," and I have something more to do that [than] to feel. God almighty have us all in his keeping.
— Lamb to Coleridge. 27 September 1796
Charles took over responsibility for Mary after refusing his brother John's suggestion that they have her committed to a public lunatic asylum. Lamb used a large part of his relatively meagre income to keep his beloved sister in the private "madhouse" in Islington. With the help of friends, Lamb succeeded in obtaining his sister's release from what would otherwise have been lifelong imprisonment. Although there was no legal status of "insanity" at the time, the jury returned the verdict of "lunacy" which was how she was freed from guilt of willful murder, on the condition that Charles take personal responsibility for her safekeeping.
The 1799 death of John Lamb was something of a relief to Charles because his father had been mentally incapacitated for a number of years since suffering a stroke. The death of his father also meant that Mary could come to live again with him in Pentonville, and in 1800 they set up a shared home at Mitre Court Buildings in the Temple, where they would live until 1809.
In 1800, Mary's illness came back and Charles had to take her back again to the asylum, probably Bethlehem Hospital. In those days, Charles sent a letter to Coleridge, in which he admitte
Charles Lamb