Family and friends of the woman found dead hours after being released from Woodlands paid tribute to her "honest and caring" nature.
Laura Squire was found hanging in her Michelson Close flat in St Leonards in July 2007, just one day after being discharged from the mental health unit.
An inquest into her death, held this week, revealed that the 30-year-old had struggled with alcoholism since the age of 15 and that she was drunk when she took her own life.
However, her loving sister Victoria Hambly said she remembered her as she was without drink.
She said: "Laura was a very decent, honest and caring person and would have given anyone her last pound."
And it was a sentiment echoed by Joanna Ralph, one of Miss Squire's neighbours.
Speaking at Tuesday's inquest, she said: "She was a great girl and we used to go horse riding together. We went out for hours to walk our dogs."
Alan Hess, another neighbour, poignantly added: "She was one of the best friends I ever had. All she needed was someone to love her."
Miss Squire was taken to Woodlands, which is at the Conquest Hospital site in St Leonards, after police were called to her home.
PCSO Geraldine Hodgens, who was among officers, told the inquest: "She was hysterical saying she wanted to end her life. She was pretty distraught."
But, despite concerns raised by three mental health nurses, Miss Squire was discharged the following day after being labelled low risk.
Dr Thambirajah Jayarajah, associate specialist for NHS trust which runs the unit, said: "When the alcohol level in her blood came down there were no symptoms of depression. She was coherent and asked us to discharge her.
"There were no grounds for us to detain her and she was displaying no psychotic symptoms."
However, less than 24 hours after she returned home, she was found dead.
After hearing the inquest record a verdict of suicide, her sister Mrs Hambly said: "I am very disappointed, particularly with the doctors and some of the nursing staff."
A spokeswoman for Sussex Partnership NHS Trust, said: "The two doctors and a nurse involved in her care and treatment felt that given the circumstances and outcome of assessments they had made the correct decision to discharge Laura and she could not have been detained under the Mental Health Act."
"We have listened very carefully to the comments made by the coroner and in light of these will again review the circumstances leading up to Miss Squire's death to see if any additional actions should be taken to reduce the likelihood of such an incident happening again."