A Petroc student took her own life by overdosing on her mothers amitriptyline tablets, a coroner concluded.An inquest on Wednesday heard Siani Elland Ruby Benson-Wills, of Rolle Street, Barnstaple, had suffered with depression since the age of 13. The 18-year-old had previously been on antidepressants but was not on any prescribed medication at the time of her death on May 8, last year. The inquest heard Siani had a history of self harm, and had tried to take her own life by taking an overdose on a previous occasion. Her mother Tracie Benson said in her statement: Siani was a happy-go-lucky girl until the age of 13 when she began to struggle. She said Siani, who was also a part time bar maid, had undertaken her first year of A Levels at Petroc, before switching to a Btec in art. Ms Benson last saw her daughter alive on the evening of May 6 at their home. Siani was found dead at around 1.30am on May 8 and a post-mortem recorded a fatal level of amitriptyline in her blood as the cause of death. Coroner Dr Elizabeth Earland recorded a verdict of suicide, and said: This was an impulsive overdose but I am satisfied Siani took her own life.