A mother killed herself after she was discharged from hospital without mental health staff realising she had a long history of depression - because of a spelling blunder.Marie Natalie Piner killed herself after phoning her daughter and a friend, warning them she had large amounts of pills and intended to take them all.A massive hunt was launched for the troubled 36-year-old from Clacton, Essex, but she was found dead four days later in a car park in the seaside town.At her inquest, it emerged that before her death, Mrs Piner had been discharged from hospital after a mental health assessor misspelled her name on a computer.The assessor missed a vital apostrophe in the maiden name given by Mrs Piner and the mistake meant her long history of treatment for depression did not appear.Satisfied with her mental state, the assessor discharged her.But just weeks later on December 8 last year, her family reported her missing. The disappearance sparked a major search with the police helicopter scrambled as well as lifeboats searching for her.But Mrs Piner was found dead four days later and a toxicology report showed she had a fatal amount of the prescription opiate Tramadol in her system.Essex assistant coroner Eleanor McGann ruled the death was a suicide as a result of an overdose.She said: 'Mrs Piner had a very high level of Tramadol in her system - much higher than would be required to kill somebody.'Considering all the evidence, I am satisfied she intended to take her own life.'Since her death the NHS computer system has been revamped and it is set to go live from October.The changes mean that slight mistakes on spellings will still yield search results.