TORONTO -- Having one child with a mental health issue such as autism or attention deficit hyperactivity disorder can be challenging enough, but imagine having four affected children -- all with slightly different diagnoses.

That's the reality for Ann Douglas, whose daughter and three sons have grown up with a variety of mental health, neurodevelopmental or behavioural disorders. And the Peterborough, Ont., author is not immune herself.

Douglas has bipolar disorder and so did her mother.

In her new book, "Parenting Through the Storm," she describes her children's struggles and provides insights from interviews with more than 50 other parents of kids with mental health challenges, as well as experts. The book offers advice on how parents can be advocates for their child to get a timely diagnosis and treatment.

And how to save one's own sanity in the process.

Her eldest, daughter Julie, 26, had suffered as a teen with depression and bulimia; Scott, 24, was diagnosed in elementary school with attention deficit hyperactivity disorder (ADHD); Erik, 23, also had ADHD, as well as oppositional defiant disorder and a learning disability related to writing; Ian, now, 17, was diagnosed with ADHD, a writing-related learning disability and to top it off, Asperger's syndrome -- an autism spectrum disorder typically marked by difficulty with social interactions and a restricted range of interests.

Having more than one child with a mental health or behavioural issue may seem like the worst of bad luck, but psychiatrist Dr. Albert Wong of the Centre for Addiction and Mental Health in Toronto says the genetic variations that put one person at risk for autism, for example, may be associated with a higher risk of bipolar disorder in a sibling or depression in another.

"There is a lot of overlap in the genes and the variants in genes that confer susceptibility to various mental disorders," says Wong. "The fact that we see mental illness and behaviours running in families is not surprising."

Surprising or not, how does one cope with parenting so many affected children?

"You find yourself in the situation and you have no choice but to cope because the kids are counting on you to cope," says the author of four previous parenting books.

"That's not to say that I did a brilliant job. There were times when I was burned out, depleted, exhausted," admits Douglas, who went through a three-year period of clinical depression.

"I gained 100 pounds and that was because I put their needs ahead of my own. I wasn't sleeping enough. I was never exercising. I wasn't eating properly."

That's one of the key messages of her book: self-care can't take a back seat to caring for the children's needs. "They need you to be strong and healthy, and sometimes that means making yourself a priority in your own life."

Because of often lengthy waiting lists, it can be hard to get a formal diagnosis for a child who has obvious difficulties with school and social interactions -- red flags of something more than a temporary phase.

While it's important doctors don't jump too quickly to an incorrect diagnosis, a lag can mean a delay in getting potentially helpful therapies started, which also can be subject to long waiting lists.

Douglas says it's critical parents reach out for help in a few directions, such as to other parents and to school staff, who may know other resources to tap into -- "so you don't have to reinvent the wheel for yourself when you're exhausted and overwhelmed."

"You're not a bad parent and your child is not a bad kid. You're just in a really, really difficult situation."

While her children are doing well now, Douglas says one of the most difficult aspects of raising kids with mental health issues is feeling afraid about their future.

"At one point I talk in the book about Julie trying to injure herself by overdosing (on Tylenol). I was terrified. It was like how do I keep this child safe? So I had very bottom-line goals for her: it was like A, live; B, finish high school.

"And everything else was a bonus. I remember sitting there in tears at her high school graduation thinking: 'I can't believe we made it.' And I felt like it was definitely 'we.' Yes, she made it, but with a lot of love and support from her family."