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10 Articles in Volume 17, Issue #5
Cross-Linked Hyaluronic Acid Injection for Neuropathic Pain
Discussing Migraine: What to Try When Nothing Is Working
IV Propofol for Treatment of Chronic Intractable Cluster Headache: A Case Series
Letters to the Editor: Rapid Opioid Metabolizer, Intractable Pain, Adrenal Suppression, Traumatic Brain Injury
Migraine Treatment: What’s Old, What’s New
Schizophrenia Spectrum and Chronic Pain: Is Pain Insensitivity a Myth?
Spinal Fluid Flow and Pain Management
Step-by-Step Technique for Targeting Superficial Radial Nerve Pain
The Primary Care Provider’s Role in Diagnosing and Treating Rheumatoid Arthritis
What is the appropriate use of phone texting between physicians and patients?

Schizophrenia Spectrum and Chronic Pain: Is Pain Insensitivity a Myth?

Among patients with schizophrenia, 38% report pain, and the most common pain complaint among individuals with schizophrenia is headaches.

Schizophrenia  is most notable for its absence from the chronic pain population.1 This may be due to an unfortunate gap in the research—and it is especially important when you consider that pain is associated with reduced quality of life among patients with serious mental illness.2 Patients with schizophrenia have increased rates of serious medical problems,3 are less likely to know or understand their medical difficulties,4 and often receive fragmented or inconsistent medical care.5

The schizophrenia spectrum disorders, including schizotypal personality, delusional, catatonia, brief psychotic, schizophreniform, schizophrenia, and schizoaffective disorders, are organized along a gradient of psychopathology in the updated Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).6 Substance/medication-induced psychotic disorder, psychotic disorder due to another medical condition, and other specified and unspecified schizophrenia spectrum disorders are included as additional classifications. The diagnosis of a schizophrenia spectrum disorder requires the exclusion of another condition that may give rise to psychosis.

The schizophrenia spectrum disorders are defined by abnormalities in 1 or more “positive” and “negative” symptoms. Positive, or added on, symptoms (eg, delusions, hallucinations, disorganized thinking/speech, trouble concentrating, and catatonia) are thought patterns or behaviors that the person with schizophrenia did not have before becoming ill. Negative, or lost, symptoms (eg, apathy, emotionless responses, reduction in speech, social withdrawal, impaired attention, anhedonia, sexual problems, and lethargy) are thought patterns or behaviors that the person had before the illness. Negative symptoms of schizophrenia are not as recognized as the positive symptoms.

The prevalence of schizotypal personality disorder in clinical populations seems to be infrequent (0% to 1.9%), but it is higher in the general population (3.9%).7 The lifetime prevalence of delusional disorder has been estimated at around 0.2%,8 with the most frequent subtype being persecutory.9 Brief psychotic disorder may account for 9% of first-onset psychosis cases in the United States.10 The lifetime prevalence of schizophrenia is approximately 0.3% to 0.7%.11 Schizoaffective disorder is one-third as common,8 and the incidence of schizophreniform disorder is 5-fold less common than schizophrenia.12,13 The prevalence of substance/medication-induced psychotic disorders among individuals presenting with a first episode of psychosis in different settings is between 7% and 25%,14 and the prevalence of psychotic disorders due to another medical condition ranges from 0.21% to 0.54%.8,15

Pain More Common With Schizophrenia

The most common pain complaint among individuals with schizophrenia is headaches.16 Moreover, in a study examining the frequency of pain complaints, 38% of patients who suffer from schizophrenia reported pain.17 In 1981, Watson and colleagues examined the relationship between pain and schizophrenia. They found that patients experience pain from both physical and psychological causes, and the most common pain sites were head, leg, and back.18

More recently, Almeida and colleagues purported that chronic pain was common in patients with schizophrenia, and was similar to the general population of a similar age.19 Birgenheir and colleagues also investigated the pain rates in a sample of veterans diagnosed with schizophrenia.20 They found that 47% reported some type of pain—35% reported arthritis; 22% reported back pain; about 4% reported headache or neuropathic pain; and less than 2% reported migraine,  psychogenic, or chronic pain.

Patients with schizophrenia can present with bizarre sensory complaints, such as “pins and needles” or coenesthesia (unusual or debilitating bodily experiences that do not have an apparent somatic cause).21 These tactile hallucinations may be difficult to distinguish from other pain complaints.22

Do Patients With Schizophrenia Have Pain Insensitivity?

During my review of the literature, the notion of pain insensitivity in individuals with schizophrenia was a pervasive topic. This phenomenon would have important implications for physical health, self-mutilation, homelessness, premorbid development, and affective flattening in individuals with schizophrenia.23 As early as 1911, Bleuler noted the presence of “complete” analgesia when patients with schizophrenia incurred serious injuries (eg, removal of an eye, self-inflicted amputation of the phallus, and sitting on a hot stove).24 In 1919, Kraepelin observed individuals diagnosed with dementia praecox to be less sensitive to bodily discomfort (eg, uncomfortable positions, pricks of a needle, injuries, cigar burns, and self-injurious behaviors).25

In the 1930s and 1940s, Schneider reported “inhuman” self-injury with a lack of pain sensitivity among individuals diagnosed with schizophrenia.26 Reduced pain sensitivity was increasingly reported in clinical experiences by surgeons and internists for a variety of medical conditions or procedures, including third-degree burns,27 arthritis,28 cancer,29 fractures,30 intra-abdominal diseases,31 myocardial infarction,32 and surgery.33

This phenomenon has also been investigated in the laboratory using different types of painful stimuli, including cold pressor,34 electrical,35 imagined,36 pin prick/pressure,37 pinch,38 thermal,39 and warmth and heat pain.40 There are a variety of biological explanations for this phenomenon, including the effects of antipsychotic medications,40 dysregulation of N-methyl-D-asparate (NMDA) receptor-mediated neurotransmission,41 excess endorphins,42 genetic predisposition,43 and motor deficits.44 However, there is little to no physiologic evidence supporting pain insensitivity in schizophrenia.45 There are also other hypotheses, including psychodynamic, psychological, and sociological.46

It is more credible to assume that pain experience in schizophrenia is disturbed or distorted rather than absent.47 Pain insensitivity is believed to be related more to a different mode of pain expression than to a real endogenous analgesia. Schizophrenia is a mental disorder associated with communication and social impairments, and it may be those impairments that affect the reporting of pain.48,49 Most prior research in the literature has also failed to distinguish pain reactivity from pain sensitivity—absence of reactivity does not mean absence of sensitivity.45

How is the Diagnosis Different Now in the DSM-5?

Several changes appear in the schizophrenia spectrum section of the DSM-5.Criterion A for delusional disorder no longer requires that the delusions be non-bizarre. DSM-5 no longer separates delusional disorder from shared delusional disorder, and it is now classified as an “other” specified schizophrenia spectrum and other psychotic disorder. Three catatonic symptoms (from a total of 12 characteristic symptoms) are now required to meet criteria to diagnose catatonia whether the context is a psychotic or other mental health disorder.

Two changes in Criterion A for schizophrenia from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) were included in the DSM-5. In the DSM-5, 2 Criterion A symptoms are required for a diagnosis of schizophrenia. In addition, the individual must have at least 1 “positive” symptom. The previous DSM-IV subtypes of schizophrenia (ie, paranoid, disorganized, catatonic, undifferentiated, and residual types) were also eliminated due to their limited diagnostic stability, low reliability, and poor validity. The primary change to schizoaffective disorder is the requirement that a major mood episode be present for most of the disorder’s total duration after Criterion A has been met, which serves as a bridge between schizophrenia and major depression.

How to Assess Schizophrenia

In addition to an interview and behavioral observation of the patient, a psychological evaluation frequently includes a Minnesota Multiphasic Personality Inventory (MMPI-II). Specifically, the schizophrenia scale of the MMPI-II has been shown to differentiate chronic pain patients from psychotic and nonpsychotic psychiatric patients by the profile of symptoms they endorse.50 Chronic pain patients tend to endorse somatic symptoms and items suggestive of depression and inertia, while patients suffering from psychosis endorse items reflecting bizarre and disordered thinking, social alienation, and defective inhibition. Other psychiatric patients endorse depression, despair, thought disorganization, and social alienation. Acute symptoms of schizophrenia may be assessed using the Scales for the Assessment of Positive and Negative Symptoms.51

Schizophrenia Treatment

Patients with schizophrenia are often seen as difficult to effectively treat, and providers tend to focus on psychiatric over medical symptoms and concerns.52 Pain treatment is often considered to be of lower importance to the treatment of their psychiatric symptoms, which leads to an undertreatment of their medical conditions.53 Although patients with schizophrenia experience disparities in medical treatment, there are opportunities to improve care at the patient, provider, and systems level.  

At the patient level, morbidity and mortality can be reduced by evidence-based interventions targeting schizophrenia. Over the past several decades, medical and psychosocial treatments for schizophrenia have become more effective. Antipsychotics, also known as neuroleptics or major tranquilizers, are a class of medication primarily used to manage psychosis, principally in schizophrenia. Antipsychotic medications have been thought to have analgesic effects.54

In terms of psychotherapy, there is strong research support for social skills training (SST), social learning/token economy programs (SLTE), cognitive behavioral therapy (CBT), cognitive remediation (CR), and family psychoeducation (FP).55 SST uses the principles of behavior therapy to teach communication skills, assertiveness skills, and other skills related to disease management and independent living. SLTE programs are comprehensive behavioral programs in which participants receive “reinforcers” (such as tokens or points) for performing clearly defined target behaviors. CBT is similar to how it is used for other types of problems, including chronic pain. It involves establishing a collaborative therapeutic relationship, developing a shared understanding of the problem, setting goals, and teaching the person techniques or strategies to reduce or manage symptoms. CR improves cognitive function through repeated practice of cognitive tasks and/or strategy training. CR addresses impaired neuropsychological aspects of an individual and plays an important role in the functional impairments seen in schizophrenia. FP treatment is catered to the family members of a person with schizophrenia, and they are the focus of the intervention. FP recognizes that families can have a significant impact on their relative’s recovery and functioning. There is only modest support for other programs, including illness management and recovery (IMR), acceptance and commitment therapy (ACT), and cognitive adaptation training (CAT).55

At the provider level, medical care could be strengthened by improving communication among patients and providers. Since the research suggests that the absence of pain among patients with schizophrenia may be associated with communication and social impairments, providers may want to focus on improving these skills. See Table 1 for guidelines on how to communicate with patients with mental illness.56 In addition, communication can be strengthened by incorporating the perspective of the patient’s mental health provider.

From a systems perspective, several models of integrated care have strong research support for meeting the needs of patients with schizophrenia. For example, in Assertive Community Treatment, team members share a caseload, have a high frequency of patient contact, have low patient-to-staff ratios, and provide outreach to patients using a multidisciplinary team approach to intensive case management.55 Another program, Supported Employment, emphasizes the integration of employment and mental health services through rapid placement of individuals into jobs in their community, individualized job development, and ongoing job support.55 Supported Employment is an approach to vocational rehabilitation adapted for individuals with serious mental illness. The benefits of vocational rehabilitation are shared between schizophrenia and chronic pain.57 These advances have allowed patients to achieve improved levels of community functioning and independence.

In the next installment of A to Z Mental Health, the author will discuss sleep-wake disorders and pain.

Disclaimer: The views expressed in this article are those of the author, and do not necessarily represent the views of the Department of Veterans Affairs or any other governmental agency.

Last updated on: June 15, 2017
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