It had taken just two years for Sweet to plummet from churchgoing father of two to an insatiable gambler who pawned his wedding ring, stole his mom's credit cards and bankrupted his family with $150,000 in debt to feed his voracious desire to play the slots in Las Vegas. Before that, his only taste for gaming was the odd hand of Old Maid. What happened? No one could explain, not Sweet's wife, Kris—who filed for divorce three times but relented every time—and certainly not Sweet, 45, himself. "It was as if my mind had been hijacked," he says today. "I could not control myself."
Gambling was not his only problem. In 1998 Sweet had been diagnosed with Parkinson's disease, which caused his limbs to tremble and made movement increasingly difficult. Doctors speculated he was depressed, acting out at the slot machines. Then, on a hunch, one physician, Dr. Jeff Bronstein, decided to take Sweet off a medicine he was taking to see whether, by chance, the drug that was helping to steady his hands was also scrambling his mind. Almost immediately the craving to bet ceased. "I got the man I was in love with back," says Kris, 37, a special ed teacher.
The mild-mannered teacher's story spread through the Parkinson's community, as other patients taking the same meds—dopamine agonists—began to report bizarre, but rare, cases of unpredictable behavior. Marketed as Mirapex, Requip and Permax, the medication corrects a deficit of dopamine, a naturally occurring chemical that controls movement and is also associated with the brain's pleasure center. In some patients, perhaps one in 15, says Dr. Mark Stacy, a Parkinson's expert at Duke University, there is an unintended side effect: "What gives them pleasure takes over their life." Gambling is the most common compulsion, says Stacy, but sexual excess, binge eating and hobbies-gone-wild, like manic gardening and knitting, have also been noted (see box).
Sitting in his Southern California kitchen, a plate of homemade chocolate chip cookies on the table, Sweet hardly seems the type to have lived in his car after his wife kicked him out for draining the family bank accounts or for skipping son Evan's fifth-birthday party to gamble. "I went to my men's church group, I went to therapy, I even admitted myself to a psychiatric clinic. I was in hell and I couldn't stop it," he says. For Kris, Jim's transformation was incomprehensible. After marrying in 1992, the couple saved every spare penny so Kris could stay at home with their two children, Evan, now 10, and Amy, 12. "The one time we went to Las Vegas, we found $50 on the ground and returned it to the cashier. They laughed in our faces," says Kris.
A year after he was diagnosed with Parkinson's, Sweet started taking a dopamine agonist and soon developed an attachment to the family computer. "At first I was buying things on eBay, stupid stuff," he recalls. Like a porch swing—"and we don't have a porch." As Jim graduated to gambling, Kris was one of the last to admit he had a problem. "I was told he was depressed, that he was trying to get me to divorce him, to protect me from a life with a disabled husband," she says.
After Sweet's '01 arrest in Las Vegas, the couple sought help from Dr. Bronstein, at UCLA, who solved the mystery. Now taking other medication, Sweet no longer feels that urge, he says, "but I'm still ashamed of what happened. The only reason we made it through was our faith and family." Today all four Sweets see a therapist. "We want the kids to know this wasn't their dad's fault," says Kris. Meanwhile, though no studies have definitively linked dopamine agonists to compulsive behavior, manufacturers have added warnings to their drug packaging. "Although such reports are uncommon, we have and will continue to take appropriate steps to ensure physicians are aware of the possibility," says Mark Vincent of Boehringer Ingelheim Pharmaceuticals, which manufactures one of the drugs. Sweet, whose 2003 lawsuit against a drug-maker was subsequently resolved, says, "If you don't understand what's going on, you can lose your family or even your life. I almost did."