Sung Lee, MD, MSc, is Research Coordinator for Brain State Technologies. Lee Gerdes is the inventor of the HIRREM technology, and CEO of Brain State Technologies, LLC.
Monoamine oxidase A (MAOA) is an enzyme essential for the degradation of monoamines in the central nervous system (Oreland 1991). Previous research has shown that MAOA plays a major role in aggression. In one of the first studies, a point-mutation in the gene that codes for MAOA, PH-797804 cell line causing complete MAOA deficiency, was associated with criminal and violent behaviors
in males. This effect was seen over multiple generations Inhibitors,research,lifescience,medical in the family studied (Brunner et al. 1993). This link between lower MAOA enzyme activity and aggression has been confirmed in studies using animal models (Cases et al. 1995) and in human studies that used positron emission tomography to measure MAOA function in vivo (Alia-Klein et al. 2008; Soliman et al. 2011). The MAOA gene is located on the X chromosome (Xp11.23-11.4) and has a variable number of tandem repeats (VNTR). Inhibitors,research,lifescience,medical Alleles with 3.5 or 4 copies lead to 2–10 times more efficient transcriptional activity (indicating high expression; MAOA-H) than alleles with three copies (low expression;
MAOA-L) (Sabol et al. 1998). An early study showed that maltreated boys with the MAOA-L genotype were at greater Inhibitors,research,lifescience,medical risk to develop antisocial problems than maltreated boys with the MAOA-H genotype Inhibitors,research,lifescience,medical (Caspi et al. 2002). This finding has been replicated (Foley et al. 2004; Huang et al.
2004; Kim-Cohen et al. 2006; Nilsson et al. 2006; Ducci et al. 2008; Cicchetti et al. 2010; Enoch et al. 2010) but not consistently (Young et al. 2006; Alia-Klein et al. 2008). Although most studies have shown that the MAOA-H variant is associated with less aggressive behavior in males, this variant may be a risk factor for increased aggressive behaviors in adolescent girls who experience early psychosocial risk factors (Sjöberg et al. 2007; Åslund et al. 2011). Problems in aggression regulation are a common symptom of many psychiatric disorders. For Inhibitors,research,lifescience,medical ARCHIVES OF INTERNAL MEDICINE instance, up to 30–40% of depressed patients seem to experience some form of aggression regulation problems during their depression, ranging from irritability (Perlis et al. 2009; Verhoeven et al. 2011) to anger attacks (Fava and Rosenbaum 1999; Van Praag 2001). Consistent with this, MAOA has been linked to both aggression and the development and pharmacological treatment of depression (Pare 1985; Aklillu et al. 2009). This may suggest that the relationship between MAOA and aggression depends on the context of aggression. Indeed, a previous study has shown that the effects of the MAOA gene on aggression are most prominent in an aggression-provoking situation (McDermott et al. 2009). It is therefore of interest to assess the role of the MAOA gene in aggression-related behaviors in the context of sad mood.