New Zealand's suicide rate is higher than Australia's, with twice as many of our young men killing themselves in recent years.
The study published in the New Zealand Medical Journal compared suicide rates between the nations from 1949 to 2013, with a focus on age patterns.
In the latest year bracket available, 2009 to 2013, the rate among Kiwi men aged 20 to 24 was 29.7 per 100,000 - double the rate of Australian men of the same age group.
The study, Changes in the age pattern of New Zealand suicide rates by Australian clinical professor of psychiatry John Snowdon, was based on Ministry of Health and Australian Bureau of Statistics data, and census data.
While suicide rates were similar between the nations generally, New Zealand's rate was higher overall due to higher rates among young citizens, including a "markedly higher" suicide rate of youths.
New Zealand has continuously ranked among the worst in the world for levels of teen suicide. An OECD report published last year found we had the highest rate in the developed world.
"There must be continued concern regarding the relatively high youth suicide rate in New Zealand versus the much lower corresponding rates in Australia," Snowdon said.
Snowdon proposed substance abuse could be a factor in the rise and fall of suicide rates of young adult males.
As well as age patterns, Snowdon also compared suicide rates among Maori and non-Maori with Aboriginals and non-Aboriginals.
The suicide rates of young adult indigenous populations in both countries remained high, but there was a fall in the suicide rate of non-indigenous youths in Australia.
"Suicide appears to be especially a problem among Maori youth," Snowdon said.
The study noted explanations which have been made for the high Maori youth suicide rate including the disadvantaged status of Maori in society, cultural alienation and confusion over identity.
"It was also suggested that Maori, who traditionally identify themselves as members of a collective group, may find difficulty in societies which value individualism."
Meanwhile, there has been substantial decreases in suicide rates of Kiwis and Australians aged over 55 since the 1980s.
The study suggested this could be due to multiple factors, including greater use of antidepressants and the increased attention to the health and welfare needs of elderly people.
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)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.