A troubled teenager was driven to suicide after a doctor's letter accidentally sent to her mother revealed her cannabis and alcohol use.

Tasmin Dalton, from Eastleigh, Hampshire, hung herself only weeks after a letter meant for her GP was sent to her mother as a result of an administrative error, an inquest heard yesterday.

The 16-year-old schoolgirl, who suffered from mental health problems and had been diagnosed with psychosis after episodes of self-harming, was seeing a psychiatrist until the doctor's letter detailing her drug and alcohol problems was sent to her mother, Tracey Smith.

The inquest heard that the teenager had reacted strongly and told the psychiatrist that she felt suicidal after her private information was revealed to her mother.

Dr Moira Bingham told the inquest: "I wrote a letter to her GP, but a clerical error meant it was also sent to her mother."

The court heard that Tasmin felt hurt and betrayed and subsequently discontinued treatment with Dr Moira Bingham after composing a letter to her, which read: "I am appalled you have betrayed my trust."

Tasmin's mother said her daughter appeared calm in the days preceding her death.

Ms Smith told the coroner's court that the last time she saw her daughter was three days after she attended her school leavers' prom and she seemed happy: "She gave me the biggest smile ever.

"I thought, 'She's really changed and really grown up, leaving school.' But I think she was just saying goodbye.

"I think she made up her mind before the prom," Ms Smith added.

The day before her body was found in a woodland near her home, Tasmin had called an emergency meeting with her GP, complaining about the letter that was sent to her mother.

'I think she wanted to go happy. She had her prom, she had a party the next day and then I think she had all her friends in the park on the Monday (the day before her death)," Ms Smith told the inquiry.

"She just wanted to go not having rows with people or falling out with anybody."

A verdict of suicide was recorded.