"We are now studying medications and interventions that both downgrade stress and decrease the promotion of habits," she says. "We are going after stress-induced cravings, thinking that if you target those cravings, you may be able to stop relapse."
Stress and the brain
While we have long known about the connection between addiction and stress, and how stress can increase our susceptibility to chronic diseases, we have only recently begun to understand the biological mechanisms.
Stress triggers the evolutionary "fight or flight" arousal response, where the whole body gears up to move quickly to get out of danger. As part of this arousal, the body releases the stress hormone cortisol and ramps up by using our energy stores, which release glucose and insulin so that muscles have the energy to deal with the stress.
Substances like alcohol, nicotine and cocaine -- and high-fat, high-calorie comfort foods -- can serve as powerful modifiers of the stress system. They change our stress pathways and affect the way we are able to control our response.
The brain area most vulnerable to stress, including early childhood stress, is the prefrontal cortex, which is crucial for metabolic homeostasis, or stability, as well as for survival and adaptation.
"The prefrontal cortex is also the region important for self-regulatory activities of all kinds, both emotional and cognitive, including impulse control, and regulation of emotion, cognition and desires," says Sinha.
Constant battering by stress wears down our ability to counteract potentially dangerous desires, such as cravings for addictive substances or foods. Control over impulsive and dangerous behavior may also wane. This is the dynamic that places children from troubled home environments, and people suffering from addictions, most at risk.
The buck stops here
The Yale Stress Center's clinical practice offers both behavioral and physical health care that incorporates traditional interventions like medication and therapy, along with alternative ones, such as yoga, mindfulness meditation, acupuncture and biofeedback.
"We are finding that stress reduction interventions like mindfulness-based meditation can be extremely helpful to impact the stress cycle," observes Sinha. "But the difficulty is that meditation on its own may not be enough to help addicted individuals." And so Sinha and her colleagues are continuing to develop multipronged interventions that may also include coaching, physical therapy and medications.
Sinha's work, which started with the interaction between stress and addictive behavior, eventually expanded to include the gamut of behavioral addictions, from food to gambling to sex. She has also begun contemplating the effects of stress on motivated behaviors, both healthy and unhealthy, such as exercise and proper nutrition.
She is particularly interested in food addiction right now; she's concerned about the obesity epidemic and stress-induced eating.
She agrees that social and public health interventions are very important. When the cigarette tax was implemented and smoking was banned from public places, there was a dramatic drop in use. However, there are still a substantial number of people smoking.
"And you really can't ban alcohol and high-fat foods. The buck has to stop at the individual level. My interest is in the connection between stress and behavior, and in finding ways to strengthen the mind and body so that we can resist both mental and physical disease."
Sinha is not dancing much these days. "I am completely engaged with my work," she says. "But I find it interesting that the dancing I did as a child and young person became the cornerstone of my work, that it shaped my career the way that it did."
And as Sinha finds herself in a clinical care practice that includes yoga and mindfulness, she often feels as though she has come full circle, because "part of classical Indian dance is based on yogic principles."
In its own way, she says, it has been an interesting and unexpected journey back home.