The “outer dimensions”: impulsivity, anger/aggressiveness, activation

The “outer” SVARAD dimensions, impulsivity, anger/aggressiveness, and activation, represent trans-diagnostic psychological and behavioural domains that span traditional categorical boundaries. At the neurobiological level, the fronto-limbic and the fronto-cerebellar circuitry, as well as molecular pathways involving dopamine, serotonin, testosterone, and inflammatory mediators, play a crucial role in mediating the biological underpinnings of these psychopathological dimensions. From a clinical perspective, as the combination of clusters of symptoms differs from patient to patient and gives rise to a wide variety of clinical pictures even among subjects with the same diagnosis, it is important that the clinical features related to impulsivity, anger, aggressiveness, and activation are specifically and multiparametrically investigated and treated. The aim of the present chapter is to discuss the psychopathological aspects, the neurobiological underpinnings, and the clinical implications related to the “outer dimensions” in clinical psychiatry.