From the Research
Definition of Delusions
- Delusions are commonly defined as false beliefs that are incongruent with reality 1
- They are a type of distorted representation of reality, which can be about the present or the personal past 2
- Delusions are often associated with psychiatric illnesses, such as schizophrenia, and can also be present in neurodegenerative disorders, like Alzheimer's disease and fronto-temporal dementia 1
Characteristics of Delusions
- Delusions are marked by subjective certainty and incorrigibility, meaning that the individual holding the delusion is convinced of its truth and resistant to contradictory evidence 3
- They can be fixed or variable, and their content can range from persecutory to grandiose 3
- Delusions can be experienced as a false memory or a distorted perception of reality 2
Types of Delusions
- Delusions can be categorized into different types, including doxastic (belief-based) and anti-doxastic (non-belief-based) views 4
- Doxastic views propose that delusions are a type of belief, while anti-doxastic views argue that they are not 4
- There are also revisionist and non-revisionist proposals within the doxastic camp, and commonsensical and non-commonsensical anti-doxasticisms within the anti-doxastic camp 4
Neural Correlates of Delusions
- Delusions have been associated with gray matter reductions in various brain regions, including the dorsolateral prefrontal cortex, left claustrum, hippocampus, insula, amygdala, thalamus, superior temporal gyrus, and middle frontal gyrus 1
- The neural correlates of delusions can vary across different disorders, such as schizophrenia, bipolar disorder, Alzheimer's disease, and Parkinson's disease 1
Subjective Experience of Delusions
- Delusions can be a complex and individualized phenomenon, emerging from a dynamic interplay between interdependent subpersonal, personal, interpersonal, and sociocultural processes 5
- The subjective experience of delusions can involve a radical rearrangement of the lived world, dominated by intense emotions, and a search for meaning, belonging, and coherence beyond mere dysfunction 5