Funding, obviously, is part of the problem. Fifteen million children in the United States now suffer from some mental health disorder, and the Centers for Disease Control and Prevention reports that their numbers have been rising since at least the mid-1990s. But at the same time, spending on mental health treatment as a share of overall health spending declined from more than 9 percent in the mid-1980s to 7.4 percent in 2004, where it remained through recent years.

Resources aren’t the only problem. Psychologists and psychiatrists are still befuddled by basic challenges, beginning with diagnoses, which, for children, can change as they develop. In the 1990s, Meggan was told she was bipolar, then, 10 years later, that she was a high-functioning autistic and, more recently, according to her mother, a borderline personality. She has given up listening to doctors. “I am myself,” she insists, “my own unique flavor of mental health — ‘Meggan’s Syndrome’ — which is pretty awesome!”

After diagnoses, there’s the problem of medication. Certainly the advent of anti-psychotic medications has helped improve the treatment of the mentally ill, but dosages are still largely based on trial and error. Many of these drugs lack a Food and Drug Administration recommendation for children and adolescents — but that doesn’t mean they aren’t given to them. Meggan and Daniel were both prescribed a cocktail of drugs as children, one of the first being the mood stabilizer Lithium. According to a 2012 study in JAMA Psychiatry, the rate of antipsychotic drugs administered to children between 1993 and 2009 — Abilify, Geodon, Seroquel and others — has increased by a factor of nearly eight (for adults, the rate has only doubled). And, according to the G.A.O., foster children receive these medications up to four times more often than kids in the general population.

Studies have demonstrated that talk therapy or talk therapy combined with medication is more effective than meds alone. But there aren’t enough qualified psychiatrists and psychologists to provide that therapy. Today there are around 7,400 child psychiatrists practicing in the United States (roughly one for every 2,000 patients), compared with 4,600 in 1992. By 2020 there will be around a thousand more, though the American Academy of Child and Adolescent Psychiatry estimates that we will need double the current number by then.

I hadn’t communicated with Meggan since the book was published, so this summer I set up an appointment to talk. Now 38, she is the same vivacious and manic Meggan, laughing, crying and contradicting herself. We talked in a conference room at the medical center where she now works — and where she was once an inpatient.

She’s had an “up and down” life, she told me. On the plus side, she’s a college graduate with a degree in biology and three children. But she feels lonely and isolated. She is going through a divorce, and about three years ago was cited for marijuana possession, the use of which prompted her parents to seek custody of her children. She stopped cold turkey, and the suit was settled privately. She often works seven days a week, but her parents continue to supplement her income.