Clinical Pain in Schizophrenia: A Forgotten Area

Abstract

Results from several studies suggest that pain experience is diminished in people with schizophrenia. A reduced sensitivity for pain would have implications for treating people for painful conditions in clinical practice. In this chapter, a short overview of pain in schizophrenia is provided along with discussion of some theoretical suggestions concerning the neuropathology of schizophrenia in pain-processing areas. Additionally, we mention possible confounders for pain research in persons with schizophrenia.

Severe Burns and Amputation of Both Arms in the First Psychotic Episode of a Schizophrenic Patient

“…Pain is a multidimensional phenomenon which includes sensory (intensity, nature, duration, and location of pain), emotional (galling characteristics of pain), and cognitive (mental processes that give meaning to pain perception and articulate behavioral response) components, which implies that pain is often an individual and subjective experience [ 7 , 8 ]. However, the archaic paradigm that characterized the psychiatric patient as insensitive to the rigors of nature persisted until the eighteenth century, and it has subsequently influenced the description of the alleged analgesia of people with schizophrenia.…”

“…On the other hand, the positive symptoms of the disease have been associated with both increase and decrease of sensitivity to pain, depending on the types of studies performed [ 7 ]. Furthermore, it has been described that the cognitive impairment of schizophrenia might justify the abnormal expression of the painful experience because of the attention deficits of patients, the difficulty of accessing their mnemonic catalog of prior pain responses, and reduced processing speed, as well as the fact that people with schizophrenia lack spontaneity and responsiveness to show their pain complaints, causing a false impression of hypoalgesia in the examiners [ 8 ]. In general, the heterogenous clinical manifestations of schizophrenia may explain phenomena classified as hypoalgesia in acutely psychotic patients that go as far as removing one of their eyes in order to obey biblical injunctions deliriously interpreted, as well as in chronically impaired and autistic subjects, alienated and minimally bewildered in the face of their own pain experience [ 7 , 8 ].…”

“…In short, the current scientific view considers that, rather than being an alleged hypoalgesia in schizophrenia, this phenomenon is a different way of experiencing and expressing pain [ 7 , 8 ]. This is also supported and is consistent with a wide range of global changes in the experience of corporeality and relationships of the schizophrenic self with the surrounding world, perturbations which are increasingly receiving attention (e.g., cenesthetic disturbances, passivity experiences, and body image and body schema distortions, to mention the most prominent).…”

“…Although the relative insensitivity to pain in people with schizophrenia had already been discussed since the classic texts of Kraepelin and Bleuler, the mechanisms responsible for this peculiarity have not been fully clarified so far. Some authors claim a real hypoalgesia among patients with schizophrenia while others simply declare a decline in the observable behavioral response to pain [ 7 , 8 ]. The evidence that supports an apparent hypoalgesia in patients with schizophrenia contains (1) case reports in which conditions such as peritonitis, femur fracture, or myocardial infarction provoked a minimal expression of pain, (2) population studies where either lower prevalence of painful conditions in people with schizophrenia, or the opposite, lower prevalence of people with schizophrenia among the population suffering from chronic painful conditions, were detected, and (3) experimental studies in which a different pain threshold was recorded in people with schizophrenia [ 9 ].…”

“…Criticism of these studies include the small sample size, the simulating analgesic effect of antipsychotic drugs, the lack of distinction between pain perception and its behavioral expression, the lack of homogeneity among the samples studied (schizophrenia is a very multifaceted pathology), and the use of multiple experimental approaches, as well as the lack of discernment among sensory, emotional, and behavioral components involved in the painful experience of the individuals studied [ 7 , 8 ]. Just the same, clinical studies that report hypoalgesia in schizophrenia should be compared with the experimental studies in which increased sensitivity to pain was found [ 10 – 12 ].…”