Larah James first experienced feelings of anxiety four months after her daughter Abigail was born.
"I'd never suffered any anxiety or mental illnesses at all," she said. "Probably the most frightening part for me was that the feelings were very unfamiliar."
Mrs James said the initial joy of motherhood was overwhelmed by physical symptoms of anxiety, which began around the time she stopped breastfeeding.
Her heart would race and she experienced shortness of breath. She had a dry mouth and could not sit down and focus.
Mrs James suffered sleepless nights, often several in a row, and suffered rapid weight loss - an experience that would be repeated following the birth of her son Charlie.
"I became completely obsessed with sleep and not only my own or lack of it but also the sleep routines of my children," she said.
She also suffered several panic attacks that left her overwhelmed and frightened.
"I thought I was going mental," she said. "It wasn't so much the physical symptoms but the thoughts in my head, just the confusion.
She added: "It's so hard to describe what goes on in your head during a panic attack. It's like racing thoughts, it's 100 thoughts at once. You've got no control over what you're thinking."
Mrs James is not alone. Anxiety and depression felt during pregnancy through to one year after birth affects around 100,000 families every year, according to Perinatal Anxiety and Depression Australia.
"Anxiety is at least as common as depression during the perinatal period," chief executive Terri Smith said.
Research by PANDA, which operates a helpline for people affected by perinatal anxiety and depression, suggests a majority of people do not know perinatal anxiety is an illness, with almost half unable to recognise its signs.
Philip Boyce, a professor of psychiatry at Sydney Medical School, said perinatal depression and anxiety was caused by a combination of "genetic endowment, social and interpersonal variables".
"However, the majority of cases are related to psychosocial factors such as social disadvantage, lack of social support, marital or interpersonal difficulties with a lack of support and personality vulnerability," he said.
It also comes at a high cost. The direct cost of health services to deal with perinatal depression was an estimated $78 million in 2012, according to the Deloitte Access Economics report The Cost of Perinatal Depression in Australia. Indirect costs were more than $350 million, which Deloitte attributed mainly to an estimated $310 million in productivity losses.
A NSW Health spokesman said between 10 and 20 per cent of women develop a mental illness during pregnancy or within the first year after having a baby.
He said the 2010 Australian National Infant Feeding Survey suggested perinatal depression was less commonly reported among mothers who had higher levels of education, were working at the time of the survey and primarily spoke a language other than English at home. Mothers living in major cities also reported slightly lower rates of perinatal depression.
Marie-Paule Austin, a professor of psychiatry at the University of NSW and director St John of God Perinatal & Women's Mental Health Research Unit, said Australia was doing better in detecting perinatal depression and anxiety compared to a decade ago.
But she said: "We still need to come a long way in NSW compared to other states in terms of our lack of any public mother-baby beds that allows mothers to be admitted with their infant thus avoiding separation at this critical time in the infant's life."
A NSW Health spokesman said 90 per cent of these women suffered mild mental health symptoms that could be treated by their GPs or organisations such as Karitane and Tresillian.
"Of the remaining 10% of women who require specialist care for severe and complex mental health problems generally associated with significant clinical risk, a small proportion might require an admission to an inpatient unit and may also receive specialist care through public community mental health services," he said.
He said there were various primary care and specialist services, and NSW Health had spent $3 million this financial year on supporting 900 people with moderate to severe perinatal mental health disorders.
Mrs James was fortunate to have a strong support network of family and friends but she said: "For a male it can be very difficult for them to understand."
Some of her female friends understood, others did not. "Some of them normalise it and said 'It's just part of those early days. You'll get over it'."
When Mrs James realised the anxiety she felt following the birth of Abigail was not normal, she sought help from her GP.
"He certainly helped me survive the day-to day through sleep medication and also anti-anxiety medication," she said. "But I didn't really recover until she was about nine months old."
At that point, Mrs James began sleeping and eating well, and bonding again with her daughter.
Mrs James was once again beset with post-natal anxiety about three months after the birth of her son Charlie.
As soon as she was on "the slippery slope of stressing and not sleeping", she visited her G.P. and was referred to a consultant psychiatrist.
Recalling that period in her life, Mrs James said: "It was so bad. It was really frightening. I felt guilty I wasn't enjoying motherhood any more."
