Commission chair Professor Alan Merry said it was "incredibly concerning" when people were being looked after under the health care system and the system fails them and then they go and commit suicide.
"That's not to say its not complex, I mean people can commit suicide no matter what.
"But there was a lot to learn from this," Merry said.
For the first time since 2013 the mental health and addictions sector of the DHB was included in the report.
In total, 982 adverse events - meaning an unexpected or unplanned event that resulted in harm or death - were reported in the last year by private and public health services.
Of the 631 that were reported by DHBs, 317 were due to clinical management and 255 were falls that resulted in serious harm. Other highlighted reporting categories included healthcare associated infections and medication.
The year before, there were 542 adverse events reported by DHBs.
Merry said adverse events could have a devastating effect on the person involved and their family, whānau and friends.
"Every event described here has a person at its centre. Adverse event reporting makes it possible to review each event, discover the reasons behind it and put recommendations in place with the aim of preventing anything like it from happening again."
Merry said the Commission would use this information in its MHA quality improvement programme.
"One of the aims of the programme is to support providers to learn from and reduce serious adverse events. We will achieve this aim by providing guidelines and facilitating timely, consistent reporting and reviews. Improving consumer involvement in adverse events reviews and sharing findings are also important" Merry said.
The Ministry of Health endorses fully the Commission's approach of learning from each adverse event.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
If it is an emergency and you feel like you or someone else is at risk, call 111.