Eventually Ms McInally requested a discharge - and the Hutt Valley DHB sent her discharge notes to the wrong GP.
In his findings, Mr Smith said administrative errors clearly affected the thought processes of Ms McInally.
He acknowledged that the DHB had taken steps to improve their operations.
"While that is a positive step it is overdue in my view, and will need continual monitoring."
In a separate case, Wellington man Timothy Wakelin, 23, died as a result of suicide in July 2012, after having been under care of mental health services at Capital and Coast DHB.
Mr Smith said Mr Wakelin had experienced several difficulties, including problems with his former partner.
Mr Wakelin had earlier tried to take his life in 2012, and was referred to the Crisis Assessment and Treatment Team (CATT), who concluded that he was suffering from depression.
The CATT continued to see Mr Wakelin before he was referred to his GP, and a copy of his patient notes were to be faxed through.
Mr Wakelin last visited his GP on July 19, where he stated he was starting to feel better, was seeing a counsellor and had stopped drinking.
However, the GP said he was unable to find any documentation sent through by CATT.
In his report into Mr Wakelin's death Mr Smith said it was not the first time patient notes had not been passed on.
"I acknowledge the hospital believed one had been completed but the general practitioner considers he did not receive one.
"This is not the first time this has occurred. I believe there needs to be a robust reporting process between the professionals to ensure such reports are both sent, acknowledged and received."
Following Mr Wakelin's death, his family said they believed ongoing care of at-risk mental patients should involve the family.
Senior manager for both DHBs, Nigel Fairley, said Capital and Coast DHB acknowledged both the necessity of family involvement and effective communication between health services.
"Since July 2012, CATT has developed a specific procedure manual that requires CATT staff to provide copies of all documentation, including assessments, to the client's GP and any relevant mental health teams before the start of the next working day."
Mr Fairley said staff must now also discuss and agree on a crisis plan with family or a nominated support person and clearly document this.
In the case of Ms McInally, the DHB unreservedly apologised to the family for the administrative errors that may have contributed to her death, he said.
"Hutt Valley DHB fully accepts the coroner's comments and acknowledges that the continuity of care for the young woman was sub-optimal. We have embarked on a programme to improve attendance at fixed appointments, in order to reduce the number of missed appointments."
Mr Fairley said a new system to send text and email appointment reminders to community mental health clients was in place.
