The legal ramifications and importance of distinguishing delusions from extreme beliefs
What is the difference between a delusion and an extreme, or overvalued, belief? This is oftentimes one of the more challenging questions for the forensic psychologist. This question has become particularly salient and relevant in the age of mass media, and is evident in the form of political radicalization, the sovereign citizen movement, conspiracy theories, lone acts of terrorism, and ideologically driven offenses. The expert’s opinion can have significant sway in a criminal trial. Incompetency, insanity, and mental health diversion, hinges on the presence of a qualifying mental illness. If a defendant’s beliefs are deemed an extreme belief as opposed to a delusion, this can limit the amount of legal maneuverability for the defense. The expert must be adept at distinguishing between the nuances of a delusion and an extreme belief.
According to the current iteration of the Diagnostic and Statistical Manual (DSM), delusions are fixed beliefs that are not amenable to change in light of conflicting evidence. A delusional disorder is defined as a mental illness that involves holding one or more delusions. It exists in the absence of any other significant psychopathology, and the person with a delusional disorder remains relatively functional. These beliefs are often fairly well circumscribed and compartmentalized. Delusions are not uncommonly reflective of one’s biography and personality characteristics, and there are oftentimes shared cultural aspects. The individual with delusions may seek confirmatory information and ignore evidence to the contrary.
On the other hand, an extreme, or overvalued, belief is one that is shared by others in the individual’s group. The belief is often relished and amplified, becomes more potent and refined, becomes increasingly resistant to challenge, and the individual may experience an intense emotional association with the belief such that acting out in service of the belief may become possible.
When distinguishing between a delusion and an extreme belief, it is imperative that the expert engage in a critical analysis of relevant factors. These include, but are not limited to, consideration of the types of beliefs, the degree of inflexibility, functional impairment, how the beliefs are maintained within a socio-cultural group, the degree to which the beliefs align with and/or are motivated within one’s socio-cultural context, evidence of psychosis, and the degree to which these beliefs are acted on or the degree to which such beliefs affect behaviors.
