Psychopathology fundamentals and clinical assessment

Psychology - Abnormal Psychology

BIOLOGICAL and BEHAVIORAL COMPONENTS of SUBSTANCE ABUSE

Compare and contrast biological and behavioral approaches to explain cravings for substances.

Throughout much of the 20th century, psychologists, criminologists, and social theorists debated the relative influence of biology (i.e. nature) and early formational experiences (i.e. nurture) in shaping adult human behavior. At the two most extreme positions, human personality development and behavior are either predetermined by virtue of genetic inheritance, or they are solely determined by the sum total of all relevant experiences that fill in the blank-slate human mind with which we are born.

The last decade before the turn of the 21st century witnessed an explosion in the practical applications of medical technology, computing power, and especially, the knowledge attributable to the Human Genome Project. Consequently, the contemporary study of human behavior, including the nature of substance abuse, no longer views the "nature/nurture" question as answerable by either approach to the exclusion of the other.

Rather, modern advances in neuroscience and brain imaging have enabled researchers to demonstrate the interrelationships between observable differences in the brains of addicted individuals and environmental influences that determine their ultimate effect on behavior (Gerrig and Zimbardo 2005).

Sophisticated genetic tests now allow the tracing of certain behavioral traits to specific genetic markers, augmenting the long-standing behavioral analyses of identical twins. Because identical twins share virtually the exact same genetic traits and inherent tendencies, situations where they are reared apart from birth have provided extremely valuable insight into the relative influence of biology and experience on individual behavior, including addictive tendencies. The evidence from twin studies suggests that genetic influence is profoundly important, but numerous studies also illustrate the degree to which specific genetic tendencies are still susceptible to external experiences that contribute to their degree of behavioral expression (Coleman, Butcher and Carson 1994).

Strict application of behaviorism to cravings associated with addiction to substances ignores the irrefutable evidence of significant differences in neural architecture and neurological responses typically identified in addiction-prone and addicted individuals (Dennet 1991). Conversely, strict application of the biological components of addiction excludes equally strong evidence of the influence of external environment, particularly at critical stages of development. In that regard, there is a "cross-over" effect of food being strongly associated with reward or comfort in childhood and increased tendency to seek comfort from consumption of substances as an adult (Gerrig and Zimbardo 2005).