Karen Franklin, Ph.D.
Selected Topics:
Delusions are an interesting
philosophical topic, because whether a particular belief is deemed
delusional
often depends upon the perspective of the person or cultural group
doing
the evaluating. The tendency of mental health practitioners to
disbelieve
patients has been facetiously dubbed "the Martha Mitchell effect,"
after
the U.S. attorney general's wife whose bizarre-sounding accounts of
illegal
activity in the Nixon White House were initially dismissed as evidence
of delusional thinking.
The DSM-IV defines delusions as "erroneous beliefs that usually involve a misinterpretation of perceptions or experiences." Delusions may be bizarre, that is, "clearly implausible, not understandable, and not derived from ordinary life experiences" or nonbizarre, that is, involving "situations that can conceivably occur in real life."
One problem with the DSM-IV definition is that it is not always possible to empirically determine whether the content of a belief is false. Thus, delusions can be placed on a continuum reflecting the availability of evidence that would confirm or disconfirm them.
One common misconception about delusions--reflected in the DSM-IV definition--is that the thinking processes of delusional individuals are defective, or different from those of normal people. In fact, research suggests that delusional people use the same rules of reasoning as everyone else. Indeed, once a normal individual forms a belief, he or she is also reluctant to change it, and will actively seek out confirmatory evidence ("confirmation bias") and ignore contradictory evidence. Rather than making false inferences, then, some experts now believe that delusional individuals have different experiences from other people, and that their delusional beliefs stem from their attempts to understand these experiences. Thus, it might be more useful to conceptualize delusions as disorders of experience. Delusional individuals also tend to be more alert, and indeed hyperattentive to their environment, and to notice coincidences that other people would likely think of as trivial. (See the article entitled "Delusions," cited below, for a thorough discussion of the research on how delusions are formed and maintained.)
Based on this recent evidence about the lack of defective reasoning among delusional individuals, new treatments focus on retraining individuals with delusions to approach information differently--more consciously and scientifically--than do the rest of us. Through cognitive therapy techniques, delusional individuals are trained to carefully weigh the probabilities inherent in empirical evidence, and to assign probabilities to different alternatives based on their relative plausibility. Successful treatment of delusional individuals must involve a trustful, collaborative relationship between patient and clinician.
When properly treated, delusional disorder is an illness with a reasonably good prognosis. Delusions are most amenable to treatment if they are part of a syndrome such as schizophrenia or depression, if they are not highly systematized, and if they have not been present for too long.
Structured tools exist for the evaluation of delusions (for example, the Maudsley Assessment of Delusions Schedule). In evaluating a patient's delusional thinking, it is useful to explore and describe several dimensions. These include the general theme, the degree of conviction, the systematization, the inherent plausibility or absurdity, the accompanying affect and subjective distress or worry, the influence of the ideas on the patient's actions, the relevance to the patient's everyday life, the time course, and the presence of other psychiatric symptoms.
The role of delusions in criminal adjudication has been frequently overlooked. As noted by Goldstein and Burd (cited below), "Because delusional defendants may appear to be oriented and rational, a superficial evaluation of their trial competency may not suffice." Rather, case law suggests that the depth of a delusional defendant's understanding of their legal situation must be carefully explored in order to determine whether delusions impinge upon their understanding and their ability to assist counsel in their own defense. In particular, delusional defendants may have a superficially accurate factual understanding of the proceedings, but their rational understanding and their ability to act in their own best interests may be disrupted.
For further information:
"Delusions," by Brendan Maher & Manfred Spitzer, Comprehensive Handbook of Psychopathology, 2nd Edition, 1993.
"Role of delusions in trial competency evaluations: Case law and implications for forensic practice," Alan Goldstein & Mark Burd, Forensic Reports 3, pp. 361-386, 1990.
"Acting on delusions," by S. Wessely, A. Buchanan, A. Reed, et al., British Journal of Psychiatry 163, pp. 69-76, 1993.
"An overview of treatment in paranoia/delusional disorder," by Alistair Munro & Hiram Mok, Canadian Journal of Psychiatry 40, pp. 616-622, 1995.
"Cognitive processes in delusional disorders," by Christopher Fear, Helen Sharp, & David Healy, British Journal of Psychiatry 168, pp. 61-67, 1996.
"Delusional phenomenology--Dimensions of change," by Helen Sharp, Christopher Fear, et al., Behavior Research & Therapy 34, #2, pp. 123-142, 1996.
