Psychiatric evaluations of violent political crime were mostly performed on a case-by-case basis in a forensic environment, which made them unduly dependent on categories of presumed dangerousness and legal responsibility, rather than on a clinical definition of their mental status. In referring to such “clinical” definitions, the disorder we have in mind is not limited to the major, agitated psychotic manias or mixed states. The presence of a dominant temperament, or protracted hypomania, is enough by itself to explain an individual’s engagement in a wide range of activities, not necessarily sociopathic or violent. We put forward the hypothesis that formal and transpolitical radical choices, either in favor of an illegal lifestyle or of activities involving a high level of risk, may be linked with certain mental states, especially when considering small clandestine groups showing a high level of internal ideological consensus, and a no-return attitude toward a commitment to radical choices. Available data about the psycho(patho)logical profile of terrorists are still hard to come by. The only available studies are those on identified living terrorists (judging by the trials of those who personally admitted to having been terrorists), and statistical data imply a number of documented cases belonging to the same terrorist organization. In Italy, the period often called the “years of lead [bullets]” displays an interesting viewpoint for the study of terrorist psychology, for two main reasons: first of all, it is a historically defined period (1968–1988), and second, the number of ascertained participants in terrorist activities was quite large.