Ms Al-Zuherri told the inquiry she was not surprised by Mr Nichol's death
A former social worker warned clinic staff about a man's breathing problems hours before he died of a methadone overdose, an inquiry has heard.
Corinne Al-Zuherri, 45, was a patient at Castle Craig Clinic in the Borders where Kieran Nichol, 20, died in 2005.
She told a fatal accident inquiry being held at Edinburgh Sheriff Court Mr Nichol appeared "over-medicated" on the night before his death.
The inquiry, before Sheriff Gordon Liddle, continues.
Mr Nichol, of Hawick, was admitted to the private hospital in December 2005 after relapsing into drug use following a "detox" there two months earlier.
The inquiry has heard he had depression and was a valium addict, but had only smoked heroin a few times.
In the early evening of 10 December, the day after he arrived at the clinic in Blyth Bridge, he told a group meeting he could not speak properly because he had been given heroin substitute methadone.
Ms Al-Zuherri told the inquiry: "He seemed over-medicated ... I was concerned about his level of consciousness."
She said she found him asleep in a chair later and his breathing was "raspy" and he was unresponsive.
"I went upstairs to the medical room and spoke to the staff and said I was quite concerned about Kieran," she said.
"I explained his breathing and said that he didn't seem completely awake and they said to leave it with them, or words to that effect.
"I was concerned that he was under the influence of substances enough that we couldn't rouse him."
Ms Al-Zuherri said she returned downstairs expecting medical staff to attend but no-one arrived.
Later, she and another patient again went to the medical room and told staff of their concerns and they then attended to find Kieran asleep in a chair.
She said told the inquiry that it took them some time to rouse him.
When asked how she felt when she was later told Mr Nichol had died, Ms Al-Zuherri replied: "I was upset that it had happened in hospital but, given the way he was when I saw him, it didn't surprise me."