Neurogenetics and Epigenetics in Impulsive Behaviour: Impact on Reward Circuitry

Abstract

Adverse, unfavourable life conditions, particularly during early life stages and infancy, can lead to epigenetic regulation of genes involved in stress-response, behavioral disinhibition, and cognitive-emotional systems. Over time, the ultimate final outcome can be expressed through behaviors bedeviled by problems with impulse control, such as eating disorders, alcoholism, and indiscriminate social behavior. While many reward gene polymorphisms are involved in impulsive behaviors, a polymorphism by itself may not translate to the development of a particular behavioral disorder unless it is impacted by epigenetic effects. Brain-derived neurotrophic factor (BDNF) affects the development and integrity of the noradrenergic, dopaminergic, serotonergic, glutamatergic, and cholinergic neurotransmitter systems, and plasma levels of the neurotrophin are associated with both cognitive and aggressive impulsiveness. Epigenetic mechanisms associated with a multitude of environmental factors, including premature birth, low birth weight, prenatal tobacco exposure, non-intact family, young maternal age at birth of the target child, paternal history of antisocial behavior, and maternal depression, alter the developmental trajectories for several neuropsychiatric disorders. These mechanisms affect brain development and integrity at several levels that determine structure and function in resolving the final behavioral expressions.

Cultural influences upon health, affect, self-esteem and impulsiveness: An Indonesian-Swedish comparison

“…Recent analyses have focused upon the issue of ethnicity and affective states (Arango-Lasprilla et al, 2009;Le, Lai, & Wallen, 2009) as well as health status (Goza & Ryabov, 2009;Saalfrank, Wang, & Brown, 2009). It has been found that high levels of impulsive behavior are incompatible with positive affect and self-esteem but rather are associated with negative affect, external locus of control and amotivation (Archer, Kostrzewa, Palomo, & Beninger, 2010;Archer, Oscar-Berman, Blum, & Gold, 2012;Palomo, Beninger, Kostrzewa, & Archer, 2008a, b).…”

Depressive Expression and Anti-Depressive Protection in Adolescence: Stress, Positive Affect, Motivation and Self-Efficacy

“…Here, distractiveness may be interpreted as an example of avoidance and externalizing behaviour in a stressful situation (Lahey et al, 2004), reducing school performance but elevating risk of helplessness. Amotivation, another form of avoidance, predicted impulsiveness in several different studies (Archer & Bright, 2012;Archer, Oscar-Berman, Blum, & Gold, 2012;Palomo et al, 2008). Distractiveness, although possibly moderated by stress, presents a generalized condition prevalent in adolescence (Crews & Boettiger, 2009;Lahey et al, 2004;Steinberg, Albert, Cauffman, Banich, Graham, & Woolard, 2008).…”

Impulsivity in anxiety disorders

“…A number of studies have also examined the role of MAOA and COMT genes in impulsive and aggressive behaviours (Malloy-Diniz, Lage et al 2013;Soeiro-De-Souza, aacute et al 2013;Iofrida, Palumbo et al 2014). Lastly, there are several recent contributions suggesting epigenetic processes underlying the final outcome of pathological impulsivity in neuropsychiatric disorders (Archer, Oscar-Berman et al 2012). …”