Autonomic dysregulation and the Window of Tolerance model of the effects of complex emotional trauma

Summary & key facts

This paper reviews an idea called the Window of Tolerance, which says severe emotional trauma—especially in childhood—can leave a person with an easily triggered body stress system. The authors explain how that over-reactive system can push people into extreme states of shut-down or panic. They link those states to brain systems that act fast (midbrain) and systems that change mood over time (chemical pathways that use dopamine and similar brain chemicals). The paper suggests that harmful habits like self-harm or substance use can be attempts to calm that out-of-control stress system, and it proposes that drugs aimed at these brain pathways might one day help people regulate their emotions better, but more research is needed.

Key facts:

• The paper is a review of the Window of Tolerance idea, which says trauma can narrow the range where people can feel calm and think clearly.
• The authors say the autonomic nervous system—the body system that controls automatic stress responses—can become easily triggered by reminders of trauma and push people into extreme states.
• Quick defensive reactions to trauma are linked to midbrain areas such as the periaqueductal gray, which act fast to protect the body.
• Longer-lasting changes in mood and arousal are linked to ascending chemical pathways in the brain that use neurotransmitters like dopamine. These pathways can change how awake, motivated, or low someone feels.
• An imbalance in dopamine pathways may cause rapid swings in arousal, mood, and motivation after traumatic experiences.
• The paper views self-harm and substance use in some people as attempts to control or calm an overactive stress system, rather than purely as separate problems.
• The authors suggest that studying the drug effects on these brain systems could lead to new medicines to help people who have long-term effects from severe trauma, but this is a proposed direction rather than a proven treatment.

Abstract

This paper reviews the Window of Tolerance model of the long-term effects of the severe emotional trauma associated with childhood abuse, a model which can also be applied to adult trauma of sufficient severity to cause post-traumatic stress disorder, chronic dysthymic disorders and chronic anxiety disorders. Dysfunctional behaviours such as deliberate self-harm and substance abuse are seen as efforts to regulate an autonomic nervous system which is readily triggered into extreme states by reminders of the original traumatic events. While midbrain areas such as the periaqueductal gray mediate instant defence responses to traumatic events and their memory triggers it is proposed that ascending monoaminergic tracts are implicated in longer-term changes in mood and arousal. An imbalance of ascending dopaminergic tracts may drive rapid fluctuations in level of arousal and in the associated mood, drive and motivation. Animal models of depression frequently use traumatic experiences of pain, isolation or social defeat to induce changes in mesolimbic and mesocortical dopamine systems which may alter prefrontal cortical control of midbrain defence responses. A focus on the pharmacology of the Window of Tolerance could provide advances in drug treatments for promoting emotional regulation in those who are suffering from the chronic sequelae of traumatic experiences.

Topics

Neuroendocrine regulation and behavior Neurotransmitter Receptor Influence on Behavior Stress Responses and Cortisol

Categories

Psychology Social Psychology Social Sciences

Tags

Anxiety Arousal Dopamine Dopaminergic Internal medicine Medicine Monoaminergic Mood Neuroscience Psychiatry Psychology Receptor Serotonin

Conditions & symptoms

Anxiety Depression PTSD Substance abuse disorder Addiction or harmful habbits Anxiety or worry Lack of energy or motivation Panic Sadness or low mood