Compulsive gambling has attracted a plethora of theories and a remarkable paucity of research. According to the National Foundation for Study and Treatment of Pathological Gambling, there may be 400,000 pathological gamblers in New Jersey alone. Nationwide, the problem afflicts at least 2 million adults, which ranks it in scope with schizophrenia.

Pathological gamblers show all the behavioral traits of chemical addicts. Indeed, the behavior of a compulsive gambler -- who will sacrifice not only fortune but job and family for the habit -- is uncannily like that of an alcoholic. Gamblers have long known this, as is witnessed by the role of the self-help organization Gamblers Anonymous, whose 12-step program is modeled exactly on that of Alcoholics Anonymous.

Even so, gambling has been almost totally ignored in research on drug and alcohol addiction, according to psychologist Joseph Ciarrocchi, who works in the pathological gamblers' treatment program at Taylor Manor psychiatric hospital in Ellicott City, Md. "We're 30 years behind the rest," he says.

So far the only hard information about compulsive gamblers is descriptive rather than explanatory. Treatment pioneer Dr. Robert L. Custer, a psychiatrist at the Veterans Administration headquarters here and head of the National Foundation for the Study and Treatment of Pathological Gambling, says gamblers have by far the highest levels of intelligence of any psychiatric population he has seen. He says they tend to be articulate, competitive, easily bored, hard workers and achievers.

Another characterization of compulsive gamblers comes from the Brecksville, Ohio, VA hospital, which started the nation's first gambling treatment program in 1972. Program coordinator Julian Taber says that in a study of 218 male patients he found that many had serious weight or cardiovascular problems; almost two-thirds were heavy smokers; and 62 percent had a history of alcohol or drug abuse. Most were severely depressed by the time they sought treatment and half were in trouble with the law. Taber says some had a history of sexual promiscuity so extreme that it resembled another addiction. "Gamblers need to 'score,' says Taber. "They like the challenge, the chase."

Many people suffering from chemical addictions have traits associated with antisocial personality, or sociopathy. According to Taber, gamblers also manifest these traits: thrill-seeking, short attention spans, erratic moods, impulsiveness, manipulativeness, poor interpersonal relations and an inability to delay gratification. Gamblers tend to have unusually high energy levels -- a necessary prerequisite to gambling around the clock -- and abrasive, driven personalities.

As a rule, gamblers tend to be very successful at their occupations until their addiction gets out of control. Taber says they like jobs that involve handling money and jobs in which they can be lone operators and move around a lot. Many gamblers are sports writers -- an exact analogue to the prevalence of alcoholics in the bartending business. Gamblers are also found in high numbers among lawyers, accountants, stock and bond salesmen, used-car salesmen, insurance salesmen and motor home salesmen.

Since there has been little research into the physical reactions of pathological gamblers, no one knows whether the disorder may relate, for example, to a subtle brain dysfunction, or whether gambling -- like drug use -- triggers euphoria-producing systems in the brain. Treatment people have observed, however, that many new patients exhibit an anxiety that looks very much like drug withdrawal symptoms.

It is now generally thought that addictive drugs either mimic or activate the effect of brain chemicals called endorphins, which are naturally occurring opiate-like substances. Some experts speculate that there may be a "common biological pathway" for all addictions, and that gambling, even though it does not involve ingesting a substance, may also activate the endorphin system. There is no research to back this idea up, although an Australian researcher, Alex Blaszchynski, found raised levels of endorphins in the blood plasma of race-track bettors.

Subtle neurological anomalies -- rather than simple chemical imbalances -- may be the key to part of the addiction and sociopathy problem, however. Antisocial personalities often have a history of childhood hyperactivity and attention disorders, and adoption studies have shown that a proclivity for some of the related behaviors can be inherited. In one study, for example, 23 percent of the gamblers reported pathological gambling in a biological parent.

The experts differ on whether pathological gambling is and will remain primarily a disorder of men. Some say male gamblers outnumber females by 10 to 1. Taber says the patterns are also different -- women are more likely to be attracted to games of pure chance, like bingo and slot machines, whereas men gravitate to the track and the poker table. His pet theory is that women like the illusion that they possess some "mysterious power" while men like to fancy they are endowed with "extraordinary skill."

Custer has a different view. He says the ratio of male to female gamblers is about 5 to 2, but that females are starting to "come out of the woodwork." He sees more antisocial traits among men, but he doesn't believe there is any difference in the patterns (he doesn't count bingo as gambling) -- rather, he perceives gambling as one of the few areas where women can compete successfully against men. Says Custer: "The numbers will be even by 2000."