But Austin and Catherine have taken their sufferings and transformed into an opportunity to help others.
"When I got hurt and couldn't practice law anymore, I didn't just sit on a beach or curl up in a corner somewhere. I started taking care of people. Because that was something I could do, including [helping] a couple of kids who had Fetal Alcohol [Syndrome]," Catherine said.
The difference between Fetal Alcohol Syndrome and other severe mental illnesses, like schizophrenia or bipolar disorder, they said, is that there is no treatment, because it is caused by permanent brain damage before birth.
The best thing for someone in this situation is early identification and intervention, Austin said, "to give them coping mechanisms to manage it, teach them techniques."
"It's almost like teaching someone who is blind or deaf how to maneuver around a world that they can't quite perceive," he said.
Catherine and Austin discovered, however, that many children and young adults with Fetal Alcohol Syndrome do not get early intervention. In many cases, due to poor family situations or a loss of their parents, they end up in foster care, and then, when they age out of the system, on the streets.
So, the Mardons started taking some of these teenagers and young adults into their home. They also reach out to other young adults suffering from mental illness. They throw parties for them and invite them over for the holidays.
"The most important thing when it comes to dealing with the disenfranchised is first you have to recognize their equal human dignity. And secondly, you have to take them where they are," Catherine said.
People automatically expect the mentally ill to be scary, she said. "They're humans."
"They want to be invited to Sunday dinner... They want somebody to remember their birthday. They want somebody to invite them to Christmas."
The Mardons encourage others to find ways to support young people with mental illness, especially, they said, older adults who either do not have children or whose children are grown.
(Story continues below)
Subscribe to our daily newsletter
Young adults leaving the foster care system are in need of the kind of support a family would offer, they said. While there are charities to provide financial support and resources, these individuals often miss out on the practical advice of a loved one and the chance to form healthy relationships with others.
"Somebody's got to take care of them," Catherine said.
Austin said what he would like Catholics - both priests and laity - to understand about mental illness is "that today there are effective treatments," through both medication and therapy.
He added that some Catholics think mental illness is a character flaw that can be solved by prayer. This is a dangerous misconception, he warned.
"We don't say that you should pray instead of take medication for your heart, but many Christians and Catholics believe that [mental illness] is a character flaw…It's not a character flaw," he emphasized.
Austin often speaks on the topic, and he said his faith always informs his advice for people with mental illness or for their family members.