Adult hippocampal neurogenesis in the pathogenesis of addiction and dual diagnosis disorders

Abstract

Background As knowledge deepens about how new neurons are born, differentiate, and wire into the adult mammalian brain, growing evidence depicts hippocampal neurogenesis as a special form of neuroplasticity that may be impaired across psychiatric disorders. This review provides an integrated-evidence based framework describing a neurogenic basis for addictions and addiction vulnerability in mental illness. Methods Basic studies conducted over the last decade examining the effects of addictive drugs on adult neurogenesis and the impact of neurogenic activity on addictive behavior were compiled and integrated with relevant neurocomputational and human studies. Results While suppression of hippocampal neurogenic proliferation appears to be a universal property of addictive drugs, the pathophysiology of addictions involves neuroadaptative processes within frontal-cortical-striatal motivation circuits that the neurogenic hippocampus regulates via direct projections. States of suppressed neurogenic activity may simultaneously underlie psychiatric and cognitive symptoms, but also confer or signify hippocampal dysfunction that heightens addiction vulnerability in mental illness as a basis for dual diagnosis disorders. Conclusions Research on pharmacological, behavioral and experiential strategies that enhance adaptive regulation of hippocampal neurogenesis holds potential in advancing preventative and integrative treatment strategies for addictions and dual diagnosis disorders.

Alterations of neuronal precursor cells in stages of human adult neurogenesis in heroin addicts

“…These data suggest an impairment of neurogenesis after long term drug addiction with known heroin abuse. Thus, this work supports the hypothesis (Chambers, 2013;Mandyam and Koob, 2012) that chronic drug abuse (e.g., heroin) decreases the ability to develop new neurons in the human brain and leads to morphological changes of the targeting neurons and of glial cells . The potential role of newly formed neurons from the SGZ was suggested to be crucial for memory processes (Koehl and Abrous, 2011).…”

“…Actually, none of these dealt with the consequences of chronic drug addiction in human brains. While several animal studies suggested a negative influence of drug addiction on adult neurogenesis (Arguello et al, 2009Chambers, 2013;Eisch et al, 2000;Fischer et al, 2008;Kahn et al, 2005;Mandyam and Koob, 2012), human data in this context are still not available. The present study describes, for the first time, qualitative and quantitative changes of immunohistochemical staining patterns associated with adult neurogenesis in human healthy controls compared to cases of drug addicts with known heroin abuse, in early and middle adulthood.…”

Estrogen receptors in the central nervous system and their implication for dopamine-dependent cognition in females

“…Moreover, women respond better to antipsychotic drugs when they are administered in conjunction with E2 (Akhondzadeh et al 2003, Kulkarni et al 2014). Lastly, addiction is also related to dysfunctional dopamine transmission; repeated drug use is associated with a decrease in dopamine release in the STR and NAc (Volkow et al 2009), and significant decreases in adult hippocampal neurogenesis leading to changes in the striatal-cortical-frontal circuitry (Chambers 2013). There are sex differences in the development of addiction, as women escalate use of drugs, including opiates, psychostimulants, and nicotine more rapidly than men (Hernandez-Avila et al 2004, Lynch et al 2002).…”

Prescription drug monitoring program data tracking of opioid addiction treatment outcomes in integrated dual diagnosis care involving injectable naltrexone

“…Pre‐existing mental illness is major risk factor for acquisition of opioid use disorders, and non‐medical opioid use that escalates to addiction is a risk factor for onset of mental illness 13. Whether produced by “Adverse Selection” where doctors are more likely to prescribe high risk opioid regimens to high risk (eg, mentally ill/addicted) patients,14, 15 or biological vulnerability to addictions in mentally ill brains,16, 17 strong linkages between mental illness and opioid addictions indicate the need to recognize and treat prescription opioid addictions in behavioral health settings.…”