Recent Work on the Nature and Development of Delusions

Abstract

In this paper we review two debates in the current literature on clinical delusions. One debate is about what delusions are. If delusions are beliefs, why are they described as failing to play the causal roles that characterise beliefs, such as being responsive to evidence and guiding action? The other debate is about how delusions develop. What processes lead people to form delusions and maintain them in the face of challenges and counter‐evidence? Do the formation and maintenance of delusions require abnormal experience alone, or also reasoning biases or deficits? We hope to show that the focus on delusions has made a substantial contribution to the philosophy of the mind and continues to raise issues that are central to defining the concept of belief and gaining a better understanding of how people process information and learn about the world.

Looking into a Deluded Brain through a Neuroimaging Lens

“…Delusions are irrational, tenacious false beliefs held strongly despite logical, objective, and unanimous counterarguments that while they can be based on cultural and religious customs are considered out of context (Bell and others 2006; Bortolotti and Miyazono 2015; Kiran and Chaudhury 2009). These seemingly incorrigible beliefs are of great value as a landmark for diagnosis of a range of neuropsychiatric disorders such as schizophrenia and the more rarely occurring, delusional disorders (Bell and others 2006).…”

“…Delusions are arduous to study because they are basically conceptual rather than behavioral, and there is a lack of animal models sufficient to study delusions, especially as they involve aberrations of uniquely human faculties, including reasoning, perception, and consciousness (Corlett and others 2010). Moreover, scientists have not reached a consensus on the nature of delusions, and it is debated whether they are beliefs or an act of imagination (Bortolotti and Miyazono 2015). In addition, to the best of our knowledge, no task has been developed so far to reliably evoke delusions in individuals while under clinical observation in order to better assess findings of neuroimaging studies, and therefore, data available from those suffering from active, delusional events are limited.…”

Too much or too little? Disorders of agency on a spectrum

“…In these cases-such as Freud's patient Emmy-guilt shapes one's perception and appraisal of other people, objects, and events. In this sense, pathological guilt shares important similarities with delusional beliefs: one's belief of being responsible brings about an experience of reality in which environmental stimuli are overwhelmingly interpreted in light of such conviction (Bortolotti and Miyazono 2015).…”

Filosofía de la mente y Psiquiatría alcances y límites de una perspectiva naturalista para el estudio de los delirios

“…Si bien hay mucha controversia respecto a cómo definirlos, en particular porque ninguna de las definiciones actuales parece ofrecer criterios suficientes y necesarios (Miyazono & Bortolotti, 2015), la definición provista por la quinta edición del Manual diagnóstico y estadístico de los trastornos mentales (dsm v) dice lo siguiente:…”

“…Cuando una falsa creencia implica un juicio de valor, se considera como un delirio solo cuando el juicio es tan extremo como para desafiar la credibilidad. (American Psychiatric Association, 2013, p. 824) Por otra parte, en el marco de las discusiones filosóficas sobre los delirios, los defensores del enfoque doxástico, esto es, delirio como creencia (Bayne & Pacherie, 2005;Bortolotti, 2005;Miyazono & Bortolotti, 2015), han señalado que hay al menos tres componentes centrales de la creencia delirante:…”