Brain-derived neurotrophic factor and inflammation in depression:Pathogenic partners in crime?

Major depressive disorder is a debilitating disorder affecting millions of people each year.Brain-derived neurotrophic factor(BDNF)and inflammation are two prominent biologic risk factors in the pathogenesis of depression that have received considerable attention.Many clinical and animal studies have highlighted associations between low levels of BDNF or high levels of inflammatory markers and the development of behavioral symptoms of depression.However,less is known about potential interaction between BDNF and inflammation,particularly within the central nervous system.Emerging evidence suggests that there is bidirectional regulation between these factors with important implications for the development of depressive symptoms and antidepressant response.Elevated levels of inflammatory mediators have been shown to reduce expression of BDNF,and BDNF may play an important negative regulatory role on inflammation within the brain.Understanding this interaction more fully within the context of neuropsychiatric disease is important for both developing a fuller understanding of biological pathogenesis of depression and for identifying novel therapeutic opportunities.Here we review these two prominent risk factors for depression with a particular focus on pathogenic implications of their interaction.

Understanding that Addiction Is a Brain Disorder Offers Help and Hope

We refute the controversial statement that addiction is not a brain disorder. Extensive peer-reviewed studies support the underlying neurobiological and neurogenetic basis of addiction’s “disease model”. In the 70s and 80s, a few clinical scientists suggested that it is possible to use behavioral training to teach controlled drinking. However, this controversial model failed drastically and increased labeling and stigmatization. Additionally, it was unhelpful in the search for treatment. Instead, we assert that addiction is a neuropsychiatric disorder characterized by a recurring desire to continue taking substances despite harmful physical and mental consequences. Work from our laboratory in 1995 supported the Reward Deficiency Syndrome (RDS) concept based on a common neurogenetic mechanism (hypodopaminergia) that underlies all substance and non-substance addictions. Non-substance addictions include behaviors like pathological gambling, internet addiction, and mobile phone addiction. Certain impulsive and compulsive behaviors or the acute intake of psychoactive substances result in heightened dopaminergic activity, while the opposite, hypodopaminergia, occurs following chronic abuse. Patients with Substance Use Disorder (SUD) can have a genetic predisposition compounded by stress or other epigenetic insults that can impact recovery. Relapse will occur post-short-term recovery if dopaminergic dysfunction remains untreated. Addiction, a brain disorder, requires treatment with DNA-directed pro-dopamine regulation and rehabilitation.

Hypothesizing That Pediatric Autoimmune Neuropsychiatric Associated Streptococcal (PANDAS) Causes Rapid Onset of Reward Deficiency Syndrome (RDS) Behaviors and May Require Induction of “Dopamine Homeostasis”

Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, or obsessive-compulsive disorder (OCD), whose symptoms are exacerbated by group A streptococcal (GAS) infection. PANDAS has been known to cause a sudden onset of reward deficiency syndrome (RDS). RDS includes multiple disorders that are characterized by dopaminergic signaling dysfunction in the brain reward cascade (BRC), which may result in addiction, depression, avoidant behaviors, anxiety, tic disorders, and/or OCD. According to research by Blum et al., the dopamine receptor D2 (DRD2) gene polymorphisms are important prevalent genetic determinants of RDS. The literature demonstrates that infections like Borrelia and Lyme, as well as other infections like group A beta-hemolytic streptococcal (GABHS), can cause an autoimmune reaction and associated antibodies target dopaminergic loci in the mesolimbic region of the brain, which interferes with brain function and potentially causes RDS-like symptoms/behaviors. The treatment of PANDAS remains controversial, especially since there have been limited efficacy studies to date. We propose an innovative potential treatment for PANDAS based on previous clinical trials using a pro-dopamine regulator known as KB220 variants. Our ongoing research suggests that achieving “dopamine homeostasis” by precision-guided DNA testing and pro-dopamine modulation could result in improved therapeutic outcomes.