LAUSR

The rationale for selective serotonin reuptake inhibitor (SSRI) treatment in patients with aggressive behavior comes from several studies aimed at comprehending the neurobiological basis of anger and aggression and, in particular, at investigating the involvement of the serotonergic system in the modulation of offensive aggressive behavior. The serotonergic system has been originally described as playing an inhibitory control on aggressive impulse. This contributed to define the so-called “serotonergic hypothesis of aggression”, which considers the central serotonergic tone as inversely related to aggression. Reduced concentration levels of both serotonin (5-HT) and its main metabolite, 5-hydoxyindoleacetic acid (5-HIAA), were described in aggressive subjects (Giacalone et al., 1968) as well as in individuals with a history of aggression (Brown et al., 1979) and impulsive aggression (Linnoila et al., 1983). Understanding the neurobiological aspects of the serotonergic system, and particularly the way how it modulates offensive-aggressive behavior could be of particular relevance from different points of view. First of all, anger, together with aggression (considered its behavioral aspect), is not a mere psychiatric condition, being typically described within the behavioral components of several neurological conditions (Finkel et al., 1996; Kim et al., 2002). Furthermore, aside from mood and behavior, serotonin also modulates a broad spectrum of functions, including cognition, learning, memory, reward processing, sleep, as well as brain development and aging so that, in the last decades, several clinical and brain imaging studies investigated the pathological modifications of serotonergic transmission in Alzheimer Disease and other dementia (Rodríguez et al., 2012; Pourhamzeh et al., 2021). Finally, through its dedicated pathways and interaction with cholinergic, glutamatergic, GABAergic, and dopaminergic transmission systems, abnormal 5-HT neurotransmission has been also described in the early stage of stroke (Rocco et al., 2007) and Parkinson Disease (Huot et al., 2011; Pagano and Politis, 2018), as well as in migraine (Deen et al., 2017) and multiple aspects of epilepsy, including seizure susceptibility, sudden unexpected death, impaired breathing, cardiac function, and arousal during and after seizures (Zhan et al., 2016; Gilliam et al., 2021). Pharmacological and neurochemical studies implicated serotonergic processes in the regulation of impulse-control disorder (ICD) and related disorders, like aggressive and antisocial personality disorder (Coccaro, 1989), kleptomania, pyromania, intermittent explosive disorder (IED), and Edited by: Christine DeLorenzo, Stony Brook University, United States