There’s a beast out there, and it’s preying on children. I know; it preyed on me. It’s called bipolar disorder, and it’s a devastating mental illness that causes intense mood swings, wild and reckless behavior, emotional anguish and suicidality. And it’s being diagnosed more and more frequently in children and adolescents. To date, over one million children have been diagnosed as bipolar.

It’s a very big beast.

Not my child, you think. Sure, she gets pretty moody now and then, but what child doesn’t? Her grades are decent, she doesn’t really have problems in school, her teachers think she’s doing well, she can’t possibly be mentally ill.

Well, I was a straight-A honors student, a cheerleader, a student Council officer and valedictorian of my high school graduating class. And yet at the age of seven, I had tried to kill myself. As I explain in my new book The Dark Side of Innocence: Growing Up Bipolar, I was so depressed about possibly getting a bad grade on a homework assignment, I saw no way out but to swallow a bottle of my mother’s pills. Fortunately, they were just diuretics, so I didn’t die. I was able to hide the incident from my parents, but I’m sorry to say it was the first of many attempts to end my own life.

What were my parents missing?

It wasn’t that they were bad parents. My father adored me, and my mother was a registered nurse. They both worked hard to keep my brother and me in private school. But they didn’t put two and two together; they didn’t notice how much school I kept skipping, claiming to be sick with asthma or the flu when the truth was, I just couldn’t get out of bed. I couldn’t move, the weight on my heart was so heavy. They didn’t notice that after every one of my “spells,” as we called them, I would come roaring back to life. I’d be hyper-energetic, charismatic and charming. I didn’t need to sleep or eat. I’d finish up all of the homework assignments I’d missed and throw in an extra credit report or two, just to make sure.

Maybe I talked a little too fast and maybe my ideas were a bit extreme (when I was twelve, I tried to convert the entire sixth grade to communism), but the word “manic” never entered my parents’ heads, and it never once occurred to them that this repeated roller-coaster behavior might signal anything more than a childish volatility.

Granted, this was way back in the sixties and seventies, when nobody talked about bipolar disorder at the dinner table. Nobody talked about mental illness, period, so I can excuse my parents’ ignorance, but that doesn’t mean that I don’t regret it. Study after study has demonstrated that early intervention can make a world of difference in the course of the disease, delaying full-blown onset and minimizing the severity of episodes.

Today’s parents have the luxury of television ads, billboards and magazines touting the latest pharmaceutical fixes for bipolar disorder. There are wonderful Internet organizations like the Child and Adolescent Bipolar Foundation and The Bipolar Child, which exist to educate the public about childhood bipolar disorder. But mostly what a parent needs to do is what a parent does most naturally: watch your child carefully.

Symptoms of depression are well-known to most of us and not so different in children: lethargy, lack of energy, feelings of extreme sadness and hopelessness. Symptoms of mania are somewhat different in children than in bipolar adults. Rather than the classic high-flying manic euphoria, children seem to experience more irritability. They may speak more quickly than usual, their thoughts may seem to race by, and their schemes may be unusually grandiose.

What’s key, however, is a pattern of instability. Does your child repeatedly have ups and downs, accompanied by swings not just in his mood but in his appetite and sleep habits? At first, this might be a little hard to spot, because unlike adults with bipolar disorder, children are more likely to have “rapid cycling,” where they veer from mood to mood very quickly, even in the course of a single day. To keep track of mood cycling, I’m a big proponent of the old-fashioned mood chart that hangs on the refrigerator door (but of course, there’s also an app for mood-tracking too).

The fact that your child only acts out at home and doesn’t seem to get into any trouble in school may be irrelevant. This is a quite frequent phenomenon, maddening for parents but not at unusual. So don’t let your child’s good grades or academic equanimity lull you into complacency. Don’t be blinded by the facade, as my parents were.

Bipolar disorder a very big beast, and it wants to be seen. But you have to be watching out for it.