Pathological fixation – preoccupation with a person or a cause that is accompanied by deterioration in social and occupational functioning – has been found to precede most cases of targeted violence. It is clinically observed and theorized to have three different cognitive-affective drivers: delusion, obsession, or extreme overvalued belief. Each driver is explained, and case examples are provided in the context of threat assessment. Extreme overvalued belief as a new concept is discussed in detail, both its historical provenance and its demarcation from delusions and obsessions. Threat management for each separate cognitive-affective driver is briefly summarized, based upon current clinical findings and research. Emphasis is placed upon understanding both the categorical and dimensional nature (intensity) of these cognitive-affective drivers, and suggested guidelines are offered for the assessment of such in a clinical examination by a forensic psychiatrist or psychologist.