A new study by a team of scientists from Yale University has recently discovered neural circuits that help to cope with stress, and in the process have found reasons why different people react differently to stress. The results of the study have shown that neuro-flexibility response in the prefrontal cortex during stress had higher levels of self-reported binge drinking, anger outbursts, and other maladaptive coping behaviors.
The research was published online in the Proceedings of the National Academy of Sciences, and conducted by scientists Rajita Sinha, PhD, and Dongju Seo, PhD. They used a brain scanning technique called functional magnetic resonance imaging (fMRI) to measure localized changes in brain activation during stress by detecting changes associated with blood flow. Study participants were given fMRI scans while exposed to highly threatening, violent and stressful images followed by neutral, non-stressful images for six minutes each. While conducting the scans, researchers also measured other indicators of stress among study participants, such as heart rate and cortisol levels, a stress hormone, in blood.
“This important finding points to specific brain adaptations that predict resilient responses to stress,” said George F Koob, PhD, Director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of NIH and a friend of the study. “The findings also indicate that we might be able to predict maladaptive stress responses that contribute to excessive drinking, anger, and other unhealthy reactions to stress.”
The brain scans revealed three distinct patterns of stress responses when compared to non-stress responses. The first pattern was characterized by prolonged activity in brain regions known to signal, monitor and process potential threats. The second response pattern involved increased activation, and then decreased activation, of a circuit connecting brain areas involved in stress reaction and adaptation, perhaps as a mechanism to reducing the initial distress to a possible threat. While the third mechanism helped predict individuals who would regain emotional stability to prolonged levels of stress, according to Dr Sinha, professor of psychiatry and director of the Yale Stress Center.
This pattern involved what Dr Sinha and colleagues described as “neuroflexibility” in a circuit between the brain’s medial prefrontal cortex and forebrain regions including the ventral striatum, extended amygdala and hippocampus during sustained stress exposure. Dr Sinha and her colleagues explain that this neuroflexibility was characterized by initially decreased activation of this circuit in response to stress, followed by an increased activation as a response to prolonged periods of stress exposure. According to Dr Sinha, this region of the brain is what enables individuals to respond to stress and regain control.
The authors note that previous research has consistently shown that repeated and chronic stress damages the structure, connections and functions of the brain’s prefrontal cortex. The prefrontal cortex is the area of the brain responsible for important functions such as language, social behavior, mood and attention, and which also helps regulate emotions, and more primitive areas of the brain.
The researchers reported that in the current study participants who did not show the neuroflexibility response in the prefrontal cortex during stress had higher levels of self-reported binge drinking, anger outbursts, and other negative coping behaviors. They hypothesize that such individuals might be at a higher risk of alcohol use disorder or emotional dysfunction problems, which are pointers of routine exposure to high levels of stress.
In addition to NIAAA, the study was supported by the NIH Common Fund, the National Institute on Drug Abuse, and the National Institute of Diabetes and Digestive and Kidney Diseases.
The Psychology Of Heavy Drinking
Drinking alcohol has clear indications of effects on social behavior such as increasing aggression, talkativeness, sexual promiscuousness and lack of judgment. Research has shown that these effects stem from our perception about alcohol though we know little about the chemical effects of alcohol itself on our behaviors.
Whilst the opposite is also true as some researches have pointed out that alcohol may actually reduce levels of aggression, reduce sexual promiscuousness and increase social anxiety. Hence our response to alcohol may vary due to social stigmas, culture and our own body’s chemistry.
According to American Psychological Association, heavy drinking stems from multiple factors, with genetic, physiological, psychological, and social factors all playing a significant role. Not every individual is equally affected by each cause. For some alcohol abusers, psychological traits such as impulsive behavior, low self-esteem and a need for approval prompt excessive drinking. Some individuals drink to cope with or manage emotional problems such as stress. Social and environmental factors such as peer pressure and the easy availability of alcohol can play key roles. Poverty and physical or sexual abuse also increase the odds of developing alcohol dependence.
Genetic factors can make individuals vulnerable to binge drinking. Being able to hold liquor poses more problems than it solves as it enables people to drink more excessively than they would in normal circumstances.
Binge drinking can cause physiological changes that make more drinking the only way to avoid pain. Individuals with alcohol dependence may also drink to reduce or avoid withdrawal symptoms.
Alcohol Changes The Neurobiology Of Brain
Drinking can become a never ending cycle as people drink to cope with stress and added pressure, and they might feel stressed due to not drinking as a result of withdrawal which snowballs the effect. Hence the stress of not drinking can increase the overall stress of an individual.
Short-term effects include memory loss, hangovers and blackouts. Long-term issues associated with excessive drinking include stomach ailments, heart problems, cancer, brain damage, serious memory loss and liver cirrhosis. Drinking problems also have a very negative impact on mental health. Alcohol abuse and alcohol induced dependence can worsen existing mental conditions such as depression or induce new problems such as serious memory loss, depression or anxiety.
The brain, like most body organs, is vulnerable to injury from alcohol consumption. The risk of brain damage and related neurobehavioral deficits varies from person to person. Alcohol accelerates the natural process of aging. Moreover, the neurotoxins in alcoholic beverages can shrink the brain and individuals prone to heavy drinking may develop permanent or transient cognitive deficits associated with brain shrinkage due to thiamine deficiency which can cause other severe problems such as short-term memory loss.