The diathesis stress model, also known as the vulnerability–stress model, is a psychological theory that disorders develop as a result of interactions between pre-dispositional vulnerabilities (the diathesis), and stress caused by life experiences. Predispositions interact with stressful experiences. When life stresses disrupt our psychological equilibrium (or homeostasis), the stressful event may catalyze development of predispositioned disorders. The diathesis–stress model explores how biological or genetic traits (diatheses) interact with environmental influences (stressors) to produce disorders such as depression, anxiety, or schizophrenia.
Thresholds
The diathesis stress model theorizes that if the combination of the predisposition and the stress exceeds a threshold, the person will develop a disorder. Science is finding genetic connections to many illnesses. However, associations between a genetic marker and the disease is less than a hundred percent. One can possess the genetic predisposition without suffering from the disease. One identical twin may develop schizophrenia but the other may not. The difference, according to the diathesis–stress model, is stress experiences of the afflicted twin exceeded a threshold, beginning a trajectory of disease.
Exceeding a threshold can be seen as emotional overwhelm, when experiences outmatch our individual resources to process the event. The threshold can be exceeded by the magnitude of a single event or the combination of multiple smaller events. Either way, we reach a limit, our ability to process is overwhelmed and we suffer damage as a result.
A negative cognitive style is strongly genetic. The more negative a person’s cognitive style, the less negative an event needs to exceed the threshold and contribute to the formation of disease symptoms. Hopelessness and depression occur more often among cognitively vulnerable people when confronted with negative events. People who do not exhibit a negative cognitive diatheses also may develop hopelessness and depression, however, the events typically must be of greater magnitude to reach their threshold (Buchanan & Seligman,1995, page 118).
Stress and the Sympathetic Nervous System
Stress fires up the sympathetic nervous system. T. Franklin Murphy explains that “the sympathetic nervous system is the branch of the autonomic nervous system that mobilizes our bodies to act” (2022). Daniel Seigel compares the sympathetic branch of the nervous system as our bodies accelerator, mobilizing energy consuming functions to deal with a stressor.
“This system can induce excitatory, arousing, energy-consuming bodily states, which are produced by the activation of…the “sympathetic” branch” (2001). Physiological examples of sympathetic nervous system activation are increases in heart rate, respiration, sweating, and states of alertness. These physical changes have a cost, and when that cost exceeds our ability to process we become vulnerable to predispositioned diseases.
We have a window of tolerance where we can process life’s demands. The stresses motivate action, we respond and our life returns to a healthy homeostatic balance where we heal from the event.
Alcoholism and the Diathesis Stress Model
Variation in a number of genes have been found to affect both alcohol consumption and alcohol use disorders (AUD). In addition, there are also numerous environmental factors, such as social environments, that also contribute to alcohol consumption and AUD. The marrying of a predisposition of genetics and a socially friendly environment for alcohol consumption may create a deadly cocktail, leading to a lifetime battle with a destructive disease (Edenberg, Gelernter, & Agrawal 2019).
Sensory Processing Sensitivity
A genetic profile that enhances stress experiences can magnify an individuals stress experiences. Sensory processing sensitivity (SPS) is a temperamental or personality trait involving an increased sensitivity of the central nervous system. A child’s sensory processing may affect the child’s development across many domains (Gee, Aubuchon-Endsley, & Prow, A. 2021).
Sensory sensitivity can impact relationships while enhancing the stress of small life events. This single genetic difference can create multiple experiences that exceeds normal processing thresholds, impacting a child’s mental health and inviting mental health challenges and diseases.
”Society tends to be built around people who notice a little less and are affected a little less deeply.”
~Elizabeth Scott
A Few Words From Psychology Fanatic
The diathesis-stress model contributes insight into the ongoing nature-nurture debate. We don’t choose our genetics and only partially choose our environments. Yet, we are not completely passive victims to a cruel game of disease. One of our best option, beyond choosing our environments wisely as we age, is to gather resources to resiliently manage stress.
Regulating stress through development of practices such as mindfulness and self-care routines can limit emotional spikes that exceed our individual thresholds to process, damaging mental health, and subjective well-being. And of course, as always, when life overwhelms, courageously seek help.
References:
Buchanan, G. M., Seligman, M. E. P. (1995) Explanatory Style. Routledge; 1st edition
Edenberg, H., Gelernter, J., & Agrawal, A. (2019). Genetics of Alcoholism. Current Psychiatry Reports, 21(4), 1-7.
Gee, B., Aubuchon-Endsley, N., & Prow, A. (2021). Perinatal Maternal Mental Health and Breastfeeding Are Associated with Infant and Toddler Sensory Profiles. Children, 8(9)
Genizi, J., Halevy, A., Schertz, M., Osman, K., Assaf, N., Segal, I., Srugo, I., Kessel, A., & Engel-Yeger, B. (2019). Sensory Processing Difficulties Correlate With Disease Severity and Quality of Life Among Children With Migraine. Frontiers in Neurology, 10
Murphy, T. Franklin (2022) Window of Tolerance. Flourishing Life Society. Published 4-21-2022. Accessed 6-9-2022
Siegel, Daniel J. (2001). The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are. The Guilford Press; First edition
