A catalogue of errors from local and national agencies in the run up to the death of a teenager has been highlighted in a new report.

Former Carshalton High School for Girls pupil Charlotte Wasey, 17, was found dead in her bedroom in Wallington having taken an overdose of her mother’s insulin in June 2011.

The death and subsequent inquest triggered a serious case review – an investigation by an independent board – which noted Charlotte’s family was known to a variety of public services since she was born, but insufficient recognition was given to the emotional harm she suffered through a lack of care from her mother.

The review raises questions about the process for protecting children in Sutton and makes recommendations to organisations involved.

Crucially, information concerning Charlotte’s welfare was not shared between the agencies she was known to – including Sutton Council, the NHS and the police.

There was also a lack of contact between mental health services dealing with Charlotte and those dealing with her mother who misused alcohol, was emotionally unstable and had a personality disorder.

The report showed Charlotte was twice hospitalised through abusing her diabetic mother’s insulin prior to her death.

Despite this, Charlotte was allowed to determine many of her own decisions – including staying at home in an environment that placed her at risk of “significant harm”.

It also reveals Charlotte’s mother attempted suicide on four occasions – three of which involved insulin – and the authorities were aware of the attempts.

It criticises professionals involved with the family who tried to accommodate the needs of Charlotte’s mother over those of her child.

The report said instead of concentrating on the mother’s insulin being stored securely, professionals should have focused on removing Charlotte from the environment.

Charlotte was subject to child protection plans from 2008, but they were hindered by bureaucratic delays and her own unwillingness to co-operate, the report says.

Kevin Crompton, chairman of the Sutton Local Safeguarding Children Board, said: “On behalf of the Safeguarding Board I’d like to offer our deepest condolences to the family [of Charlotte].

“All the local and national agencies involved are deeply sorry for what this young woman went through.

“While no one can be certain that if our agencies had acted differently this young woman would still be alive, one is left with an overwhelming sense of missed opportunities for intervention.

“Our independent review illustrates that services dealing with vulnerable young people and adults must improve their systems to share information and that professionals must take into account the whole situation when making key decisions.

“We take full responsibility for our actions and we are absolutely committed to making sure the necessary changes are made so we learn from her tragic death.”

Ofsted criticised Sutton Council’s safeguarding children department last year, branding the effectiveness of the service “inadequate”.

Since then the council has taken a number of measures to improve including replacing staff.