Maternal deprivation during the early stages of childhood can lead to depression that leads to greater vulnerability to alcohol consumption in adulthood, according to a study conducted in laboratory animals and led by Olga Valverde, leader of the Research Group in Neurobiology of Behavior of Pompeu Fabra University.
The objective of the work, published in European Neuropsychopharmacology, was to evaluate how this adversity in childhood can cause persistent alterations in behavior and in neural mechanisms that remain in adulthood.
To do this, the researchers developed a model of maternal separation after birth in rodents, which produces depressive symptoms in the animal. They used behavior assessment tests and analyzed their alcohol consumption and relapse after abstinence. Additionally, they also evaluated the presence of different compounds in areas of the brain.
The results of the study, which also included scientists from the ‘Del Mar’ Hospital Research Institute (IMIM) and the University of Barcelona, show that maternal separation compromises the reward system in the rodents. This makes the animals feel less pleasure before the consumption of positive stimuli such as alcohol, so they take more intensely.
“In a model of voluntary alcohol consumption, animals exposed to maternal separation consumed more alcohol and showed greater ease to relapse in alcohol consumption after abstinence,” explains Valverde.
Various emotional alterations
This was associated with a reduction in the levels of several compounds of the striatal monoaminergic system in the rodents’ brain. There was also a decrease in the levels of endocannabinoids –involved in the maintenance of mood and reward processes– in different brain structures, specifically in the corpus striatum and in the prefrontal cortex.
Similarly, mice exposed to maternal deprivation showed emotional disturbances related to depressive behavior, deficits in social behavior and anxiety behavior compared to control animals.
“Our findings emphasize the relevance of the first periods of life in the development of some psychiatric disorders, such as mood disorders and substance abuse disorders,” concludes Olga Valverde.