Breaking Away: The Role of Homeostatic Drive in Perpetuating Depression

The brain can be considered a complicated system of feedback mechanisms that maintain physiological homeostasis. Through psychological activity, neurochemicals act as homeostatic regulators. This study proposes that these components are part of a regulatory system that is capable of supporting multiple homeostatic regimes that, in turn, give rise to self-sustaining psychological behaviors. This project hypothesizes that such alternate regulatory programs may play a role in perpetuating psychological dysfunction. Interactions within and between components of the neurotransmitter network are represented as a set of discrete logic circuits. Neurotransmitter levels are linked to psychological constructs such as depression based on current literature. These networks were analyzed to find any stable regulatory regimes possible given the established connections. Analysis indicated that this model network supported two distinct and stable homeostatic regimes. The first corresponds to typical health, while the second presents with depression accompanied by increased and decreased levels of various neurochemicals. Treatment simulations were then run to mimic the effects of receiving an SSRI both in and out of the presence of stress, and to compare recidivism rates of returning to a normal regime to real-world statistics. This analysis suggests a new way to conceptualize depression as a naturally occurring stable regulatory regime within a complex neurotransmitter-psychobehavioral network system capable of supporting multiple stable states. Furthermore, it was found that efforts to shift the body’s stable regime from depression to health using SSRIs is impeded by stress, suggesting that some form of stress management would complement the effects of SSRI treatment

Exploring the Role of Homeostatic Drive in the Perpetuation of Depression and Anxiety Disorders

Background: Feedback mechanisms throughout the brain play a significant role in maintaining physiological homeostasis. Specifically, brain chemicals and neurotransmitters contribute important oversight of psychological activity and homeostatic regulation. We propose that these components form an overarching regulatory system capable of supporting multiple homeostatic regimes. These regimes give rise to psychological behaviors that emerge as a result of the extensive feedback mechanisms involved in neurotransmitter signaling. Methods: Here we explore the possible role of such alternate regulatory programs in perpetuating chronic psychological and mental dysfunction. To do this we represent documented interactions within and between components of the neurotransmitter network as a set of discrete logic circuits. Neuro-transmitter levels are linked to psychological constructs based on current literature. These networks were analyzed via discrete ternary logic and compared to gene expression profiles for subjects diagnosed with depression and post-traumatic stress disorder. Results: Analysis of these regulatory circuits indicated that even in the absence of external perturbations that this model neurotransmitter-psychological network supported two distinct and stable homeostatic regimes. The first corresponds to typical health and behavior, while the second displays depression and anxiety accompanied by decreased serotonin, physical fatigue, and attention, and elevated glutamate, GABA, cortisol, and epinephrine. Conclusion: From this analysis we conclude that the complexity of neurotransmitter- psychological network is capable of supporting alternate homeostatic regimes that are not characteristic of a typically healthy profile, but are nonetheless naturally supported by the circuitry. Furthermore, our analysis suggests that depression and anxiety may be perpetuated under certain conditions at least in part by the brain’s own homeostatic regulation