What is this manic depression coursing through the body and soul, this bipolar “fire and rain,” as singer James Taylor called it? What kind of mental illness inspires songs about itself and then kills the songwriter?

“Well, I think I’ll go turn myself off and go on down, all the way down,” Jimi Hendrix sang in “Manic Depression,” which he wrote in 1968, two years before his drug-related death. “Really ain’t no use in me hanging around.”

Amy Winehouse appears to have been similarly touched. The British songstress, as troubled as she was sensational, had turned her self-destruction into art. “They tried to make me go to rehab, I said, ‘No, no, no,’ ” Winehouse sang in her 2008 Grammy-winning hit, “Rehab.”

And sure enough, she was found dead Saturday in her home in London from a suspected drug overdose.

By some estimates, about 3 million people in the United States suffer from manic depressive disorder. The rate of alcoholism and drug abuse within that group of people is said to be three times that of the general population. Cocaine, heroin and alcohol are often used to self-medicate, but they only end up making the problem worse.

About 1 out of 5 people with manic depressive disorder commit suicide.

What a confounding disorder of the mind, this melancholia mated with mania, the driving force behind creative genius.

Mental illness — the subject shows up in all kinds of music, from “19th Nervous Breakdown” by the Rolling Stones, to “Lithium Sunset” by Sting, to “Down on Me,” by Janis Joplin, a manic depressive who died of a drug overdose in 1970. And yet, there is so much more to understand.

“I do drink a lot. I think it’s symptomatic of my depression,” Winehouse said in an interview on a British TV show. “I’m manic depressive, I’m not an alcoholic, which sounds like an alcoholic in denial.”

Actually, it sounds like a manic depressive who used alcohol to treat her condition — with tragic consequences.

“We have also seen that there is a greatly increased rate of depression, manic-depressive illness and suicide in eminent writers and artists,” Kay Redfield Jamison wrote in her 1993 book, “Touched With Fire: Manic-Depressive Illness and the Artistic Temperament.”

At the same time, she argued that there is “something about the experience of prolonged periods of melancholia — broken at times by episodes of manic intensity and expansiveness — that leads to a different kind of insight, compassion and expression of the human condition.

“From virtually all perspectives . . . there is agreement that artistic creativity and inspiration involve, indeed require, a dipping into pre­­-rational or irrational sources while maintaining ongoing contact with reality and ‘life at the surface.’ ”

These colliding worlds create a lot of friction, and not everyone can handle the heat.

For all of her talents, Winehouse would show up for concerts too drunk or drug-addled to perform; she’d get into fights with innocent bystanders; she’d go out in public looking like death warmed over, her body scarred with needle marks, scabs and bruises.

And yet, after the melancholia had lifted and her “blood changed into streams of fire,” as Hugo Wolf described the transition from melancholy to ebullience, Winehouse was a sight to behold.

Of course, not every artist who suffers from manic depression acts out — even those as defiant as Winehouse.

Ray Charles, for instance, opted to treat his manic depression with heroin for nearly 20 years. Like Winehouse, he sang a song about his resistance to getting professional help.

“I don’t need no doctor for my prescription to be filled,” Charles sang. “Only my baby’s arms could ever take away this chill.”

On the other hand, Kurt Cobain searched long and hard, to no avail, to cure his manic depression. In 1991, as the frontman for the grunge group Nirvana, he wrote a song called “Lithium,” the name of a powerful antidepressant. Three years later, after being released from drug rehab, Cobain committed suicide.

Winehouse’s death hit me hard because I know so many talented people who struggle with the illness. Some, like her, suffer unnecessarily. They do not seek professional help, fearing that prescription drugs will dull their senses, take the edge off of the highs and raise the bottom on the lows, robbing them of creativity. But by abusing other drugs and engaging in addictive behaviors to ease their pain, they still end up robbing themselves.

I have seen the successes, too. Some have walked into St. Elizabeths Hospital in Southeast Washington on the verge of committing suicide and emerged not long afterwards as reasonably happy people. With proper treatment, sadness need not mushroom into a debilitating despair; elation need not become reckless grandiosity and self-destructive conceit.

And while the new manifestations of creativity might not always be so intense, they aren’t likely to be as short-lived, either.

Cobain, Winehouse, Joplin and Hendrix all were 27 when they died.

In each of their cases, the symptoms of manic depression were mistaken for youthful wildness and artistic angst, when something much more serious was lurking beneath. Brilliant musicians, each was consumed by the worlds they created.

“Music, sweet music, I wish I could caress . . .” Hendrix sang, “manic depression is a frustrating mess.”