A woman lay dead in her flat for a week before a neighbour reported a "foul smell" and called the police.
Rebecca Marles, 46, was found in Kingston-upon-Thames, west London, on January 6 this year.
She was discovered a week after she was last seen by neighbours on New Year's Eve, an inquest was told, with police having forced entry to her home after an unusual smell was reported.
The woman, originally from Oxfordshire, had lost both her parents when she was younger, as well as her brother, and lived alone, West London Coroner's Court heard.
She also suffered from a number of mental health issues, including paranoid schizophrenia, and was a regular methadone user.
Met Police officers were called to her home at roughly 2pm on January 6 following a concern for welfare report after she failed to return to her local pharmacy to get her next batch of prescribed medication, MyLondon reports.
When officers arrived, there was an "unusual smell" and they were forced to knock down the door to gain entry to her flat.
Her body was found in a "decomposed state" on the kitchen floor, with a post-mortem report revealing that she had probably been lying there for close to a week having last been seen on New Year's Eve.
Met Police officer PC Lee Deakin, who attended the scene, recognised Ms Marles from a previous encounter when he had been called to her home following reports she had been burgled. He was able to identify her body.
Her GP, Dr Peter Finney, told the court that she was first diagnosed with paranoid schizophrenia in 2013, and had previously suffered multiple drug overdoses.
She was on a number of medications and had been under the care of community psychiatric teams. Mental health nurse Lucia Kendall added that she regularly smoked crack cocaine, and often reported feeling "stressed" and "agitated".
The court heard how she collected five days' worth of methadone on December 31, and a post-mortem examination and toxicology report revealed that she is likely to have overdosed on this medication, in combination with other prescribed drugs.
The medical cause of death was given as "respiratory depression", which is when carbon dioxide builds up inside the body.
Recording a conclusion of "drug-related death", West London's assistant coroner Ivor Collett told the court: "It is clear that Miss Marles found herself in such sad and stark circumstances. She was a troubled person with a number of health problems, including drug dependency.
"She lived alone and she received support from the medical services. It seems that on December 31, 2021, she collected five days' worth of methadone. It appears likely that she took a sufficient quantity of methadone with a combination of prescribed drugs, which brought about her death.
"She probably took more than she should have in order to unsettle the effects that her medication would have on her normally. She was found face down on the floor, with marks on her head, which I believe indicate that she fell. Sadly she lay on the floor for around a week before she was found. Nothing suggests any intention, it appears to have been accidental."
