A grandmother who believed she was a MI5 agent was killed by a train at Stratford station one day after being released from hospital, an inquest has heard.

Christine Mary Smith, 69, suffered fatal injuries on an underground line on July 6 last year after climbing onto the tracks and being struck by an oncoming train just after 7am.

The trained pharmacologist and former university lecturer had endured a 25-year history of mental health illness including previous suicide attempts.

She was also an alcoholic and deludedly thought that MI5 was trying to communicate with her, a jury at Waltham Forest Coroners’ Court was told on Monday.

Ms Smith, who had bipolar disorder, was sectioned as an inpatient at Goodmayes Hospital in Ilford on May 4 after falling into deep depression ignited by the death of some friends.

She was arrested the month before for harassing her neighbours during a manic phase and had stopped taking her medication.

An inquest is being held into Ms Smith’s death after she was granted a period of leave to return home the day before her death by hospital staff at North East London NHS Foundation Trust (NELFT) under section 17 of the Mental Health Act.

A risk assessment carried out had deemed the risk of Ms Smith hurting herself as low, the court heard.

Sarah Deery, Ms Smith’s daughter who lives in Sweden, said she was concerned about NELFT’s decision to release her mother.

A statement read out on her behalf by senior coroner Nadia Persaud read: “She was very depressed about the situation she was coming home to.

“What most concerned her was all the trouble she had caused while unwell.”

On arrival at Goodmayes, Ms Smith was classed as a high-risk patient but improved enough over the following weeks to be allowed home, something she wanted to do, according to two health professionals giving evidence.

Mental health nurse Oluwakemi Ipidapo, Ms Smith’s primary nurse at Goodmayes, said: “She was taking more pride in herself, she was going back to things that she loved doing.

“There was a brightness to how she talked. Before there had been a flatness.”

The inquest continues.