The good news is that difficult children tend to be interesting, bright and challenging. The bad news is that raising them may reduce other family members to mounds of quivering jelly.

Best estimates for the United States suggest that there are some 2 to 3 million "difficult" children. And, if basically "easy" children with some difficult traits are included, "we are talking about many, many more," Dr. Stanley Turecki and Leslie Tonner write in "The Difficult Child."

Despite serious research efforts, Turecki, a psychiatrist specializing in child and family health, and Tonner, a nonfiction writer, say little is yet known about the causes of difficult temperament. Although there is definitely a genetic component, experts now believe that food allergies may be a contributing factor.

Whatever the causes for difficult children, however, it is important to understand that these youngsters can be worked with -- and their behavior problems modified.

Once a difficult child is identified -- and the authors believe that this process can begin in infancy -- steps can be taken to deal with almost every symptom.

Temper tantrums, for instance, are separated into two classifications: the manipulative tantrum (for attention or control) and the temperamental tantrum (reflecting insecurity or inability to adapt). Each of these tantrum types requires a different response. With the first, the parent should display firmness and an appropriate level of disapproval. With the second, the parent should offer support and understanding.

As for specifics, the authors make some sensible, easy-to-follow recommendations. It is, for instance, wise to isolate a raging child in his or her room until the tantrum subsides. Sometimes, simply removing the child from the family "audience" is sufficient to quiet the unruly youngster.

For the child who balks at everyday requirements, such as wearing shoes, the authors suggest that parents make pre-announcements. A good example would be informing the difficult child that one is willing to change a pair of shoes twice -- but the third time, the pair stays on.

Because difficult children drain the family's energy stores, the authors caution against a "siege mentality" when dealing with them. Mothers, especially, tend to be on the "front line" with these children every hour of every day -- and a certain amount of battle fatigue can set in.

As impossible as it may seem, the key to working with difficult children lies in one's ability to remain utterly dispassionate. Difficult children, according to these authors, are reinforced in their poor behavior patterns when they succeed in evoking an irrational or emotional response on the part of the parent.

Among the most important principles in working with difficult children, they say, is consistency. Inability to keep to a firm line will often send a difficult child rocketing back into negative behavior patterns.

The authors provide numerous charts by which to measure both a child's temperament profile and effectiveness of existing discipline responses.

Turecki and Tonner also point out that, "parents' early mistakes are not irrevocable . . . Children are remarkably flexible and resilient." Despite innate personality traits, "children's development is an ongoing process.

As for the future, Turecki and Tonner write that most difficult children fall into three categories: "the child may become indistinguishable from other children . . . ; the child may develop problems in later childhood or adolescence, especially if (he or she) is poorly managed; the child will display strongly positive personality traits and . . . leadership qualities."

There is no magic to be worked here. The authors believe that parental efforts will do much to reeducate a difficult child along productive lines -- but basic temperament remains basic temperament. Meanwhile, we learn that difficult children have traditionally scored high on creativity and intelligence tests. As Turecki explains it: "I believe that certain difficult children are destined to be special members of our society . . . difficult children tend to have an overlap between vivid creative fantasy and fearfulness. In part, this is because they seem to be more in touch with how they feel . . . The circuits are open and the result is that the children seem freer, more open, intutitive, empathetic, creative and exuberant . . . "

In case there are any parents out there who need further encouragement, Turecki leaves us with a note. Among the better known difficult children is a list including Winston Churchill, Pablo Picasso, Albert Einstein, Thomas Edison and Marie Curie.

Your own difficult child may not turn out to be a genius. But with the help of Turecki and Tonner, living with the difficult child becomes a much more endurable prospect.