"This study is examining whether there are differences in smell ability and eating behaviour in women experiencing peripartum depression and those who are not," University of Otago assistant research fellow Hazel Potterton said.
Peripartum depression refers to depression linked with pregnancy itself, and for up to a year after childbirth.
Ms Potterton, of the Otago food science department, said in those with major depressive disorders, the part of the brain responsible for smelling reduced in size.
Smell ability also reduced at this time, but after successful treatment both smell ability and the brain returned to normal.
"We don't know if this is the case in mums with depression."
Smell ability at this stage was "really important as it impacts on what they eat", which then affected "their little ones," she said.
Researchers hope to recruit a total of 144 women who are pregnant or gave birth within the past 12 months.
Since the study began last year, 42 women had already taken part, and it was hoped to complete the research this year.
Half the participants being sought would have depression, but an earlier diagnosis was not needed.
The other women, without depression, would contribute through a "control" group.
There had been "no research" previously that studied "the sense of smell and peripartum depression", the study's principal investigator Dr Mei Peng, of food science, said.
Peripartium depression was believed to be underdiagnosed, and if links between smelling ability and depression were found in this group, that could contribute to better future diagnosis.
Dr Peng was "very excited" to contribute to the "very important research".
Prof Paul Glue, of the Otago department of psychological medicine, is also contributing.
More information is available via peripartumsmell.art.blog and prospective participants can email researchers at smellandppd@gmail.com.
