Review Articles: Review
Psychosocial Treatments for Multiple Unexplained Physical Symptoms: A Review of the Literature
Allen, Lesley A. PhD; Escobar, Javier I. MD; Lehrer, Paul M. PhD; Gara, Michael A. PhD; Woolfolk, Robert L. PhD
From the Department of Psychiatry (L.A.A., J.I.E., P.M.L., M.A.G.), Robert Wood Johnson Medical School–University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey; and Department of Psychology (R.L.W.), Rutgers University, New Brunswick, New Jersey.
Address reprint requests to: Lesley A. Allen, PhD, Department of Psychiatry, RWJMS–UMDNJ, 671 Hoes Lane, Piscataway, NJ 08854. Email: email@example.com
Received for publication March 1, 2001; revision received November 26, 2001.
Objective: Patients presenting with multiple medically unexplained physical symptoms, termed polysymptomatic somatizers, often incur excessive healthcare charges and fail to respond to standard medical treatment. The present article reviews the literature assessing the efficacy of psychosocial treatments for polysymptomatic somatizers.
Methods: Relevant articles were identified by scanning Medline and PsychLit. Thirty-four randomized, controlled studies were located. Whenever possible results from each study were transformed into effect sizes. An analysis of the efficacy of the psychotherapeutic approaches is provided.
Results: Various psychosocial interventions have been investigated with polysymptomatic somatizers. Although the majority of studies suggest psychosocial treatments benefit this population, the literature is tarnished by methodological shortcomings. Effect sizes are modest at best. Long-term improvement has been demonstrated in fewer than one-quarter of the trials.
Conclusions: Although seemingly beneficial, psychosocial treatments have not yet been shown to have a lasting and clinically meaningful influence on the physical complaints of polysymptomatic somatizers.
CBT = cognitive behavior therapy;, CFS = chronic fatigue syndrome;, DSM-IV =Diagnostic and Statistical Manual of Mental Disorders, fourth edition;, EMG = electromyographic;, IBS = irritable bowel syndrome.
Patients presenting with multiple medically unexplained physical symptoms, termed polysymptomatic somatizers, provide significant challenges to healthcare providers. These patients’ physical symptoms tend to be chronic and refractory to treatment (1, 2). Typically, polysymptomatic somatizers are dissatisfied with the medical services they receive and repeatedly change physicians (3). They incur excessive healthcare bills, which reflect their overuse of diagnostic procedures, hospitalizations, and surgeries (4, 5). In addition, these patients present a theoretical challenge in that the sources of their discomfort and their pathophysiology remain unclear. Because of standard medical care’s limited success in treating somatizers, alternative treatments have been developed for them.
Psychosocial treatments for somatic problems have been reviewed elsewhere (6–9). Most reviews focus on a single functional somatic syndrome, such as irritable bowel syndrome (IBS) (6), or address one unexplained symptom category, such as headaches (7) or dysmenorrhea (8). Alternatively, the most recent review examines the efficacy of only one form of treatment, cognitive behavior therapy (CBT), for patients with either a single unexplained physical symptom or a single functional somatic syndrome (9). To date, no review has produced a comprehensive comparison of all psychosocial treatments for polysymptomatic somatizing patients.
Accordingly, the present review aims to provide an analysis of the relative efficacy of psychosocial treatments for polysymptomatic somatization with an emphasis on functional somatic syndromes and somatization disorder. We focus on polysymptomatic somatizers because patients experiencing multiple unexplained physical symptoms are not clearly comparable to those experiencing just one unexplained physical symptom. Research suggests that the number of unexplained physical symptoms reported correlates positively with the patient’s degree of psychopathology and physical impairment (10). Polysymptomatic somatizers may not respond to treatment in exactly the way monosymptomatic somatizers do. Also, individual syndrome reviews may result in conclusions that are narrow and specific to that syndrome without allowing conclusions to be compared and contrasted across syndromes.
Overview of Polysymptomatic Somatizers
According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), somatization disorder is characterized by a lifetime history of at least four unexplained pain symptoms, two unexplained nonpain gastrointestinal symptoms, one unexplained sexual symptom, and one pseudoneurological symptom (11). Although somatization disorder is classified as a distinct disorder in DSM-IV, it has been argued that somatization disorder represents the extreme end of a somatization continuum (10, 12). Research suggests that patients experiencing multiple unexplained physical symptoms that fail to meet all DSM-IV criteria for somatization disorder have similar characteristics to those diagnosed with full somatization disorder (10, 12, 13).
The term functional somatic syndrome is used to describe groups of co-occurring symptoms that are medically unexplained. Many functional somatic syndromes involve only one unexplained symptom, such as jaw or chest pain. The three functional somatic syndromes whose criteria require multiple unexplained symptoms are IBS, chronic fatigue syndrome (CFS), and fibromyalgia. IBS is characterized by persistent abdominal pain along with altered bowel habits and abdominal distension that cannot be explained by organic pathology (14). A diagnosis of CFS is given for unexplained fatigue, lasting at least 6 months, that causes at least a 50% reduction in activity. Concomitant symptoms include memory impairment, sore throat, tender lymph nodes, muscle pain, joint pain, headache, nonrestorative sleep, and postexertional fatigue (15). Fibromyalgia is characterized by chronic widespread pain and multiple tender points that have no known biological basis and are often accompanied by nonrestorative sleep, fatigue, and malaise (16).
Despite the different physical complaints demarcating the functional somatic syndromes described above, similar clinical, behavioral, demographic, and physiological characteristics are observed in each syndrome (17–19). Like somatization disorder patients, individuals diagnosed with one of these syndromes are more likely to use healthcare services, report functional impairment, and suffer from psychopathology than are either healthy or medically ill subjects (5, 14–27). The overwhelming majority of CFS, fibromyalgia, and somatization disorder patients are female (12, 28, 29). The same pathophysiologic dysregulation and blunting of the central nervous system’s response to stress may be present in all of these syndromes (30). Finally, many patients diagnosed with one of the functional syndromes meet diagnostic criteria for one or more of the other functional syndromes, resulting in multisystem comorbid functional syndromes (19, 31–34). As a whole, research suggests there is substantial overlap among the functional somatic syndromes and somatization disorder (35). In fact, Wessely et al. (18) have encouraged investigators not to distinguish among the functional somatic syndromes but instead to examine them as a single classification of patients.
Because the illness behavior, psychopathology, and physical complaints of the polysymptomatic somatic disorders resemble each other, their treatments will be reviewed together. Integrating the findings from these areas of literature may unearth the consistencies and inconsistencies as well as the merits and shortcomings of the literature. The review aims to identify future directions for treating this difficult population.
Overview of the Rationales for Psychosocial Treatment Interventions
Psychodynamic theory has proposed that unexplained physical symptoms are produced to protect the somatizer from traumatic, frightening, and/or depressing emotional experiences. If an individual fails to process a trauma adequately, it is hypothesized, the original affect later may be converted into physical symptoms (36). Short-term, dynamically oriented treatments for somatizers focus on the stress and emotional distress associated with physical symptoms.
Psychophysiologists have described several mechanisms that produce somatic symptoms in the absence of organic pathology (37, 38). These mechanisms include overactivity/dysregulation of the autonomic nervous system, smooth muscle contractions, endocrine overactivity, and hyperventilation. Miscellaneous techniques, directed at reducing somatizers’ physiological arousal and physical discomfort, have been studied within controlled experimental designs, including hypnotherapy, progressive muscle relaxation, electromyographic (EMG) biofeedback, autogenic training, and multifaceted relaxation training programs.
The cognitive-behavioral model of somatization emphasizes the interaction of physiology, cognition, emotion, behavior, and environment (39). Specifically, an individual’s interpretation of physical sensations may bring on heightened awareness of bodily sensations, increased emotional distress, and self-defeating behavior (such as avoiding activities), all of which may exacerbate the physical symptoms. In turn, the environment, including family, friends, and physicians, may respond in ways that reinforce the individual’s somatic distress. Short-term CBT has been used with somatizers to alter dysfunctional cognitive processes and behavior. These treatments typically include relaxation training.
Some investigators have focused on either the cognitive or the behavioral component of CBT. Cognitive therapy teaches patients to identify associations between thoughts and physical symptoms and to modify dysfunctional beliefs. Relaxation and other behavioral techniques are not included in cognitive therapy. Behavior therapy for somatic complaints uses methods for pain management and for increasing avoided activities based on operant conditioning.
Finally, exercise treatments have been developed for somatizers in accordance with evidence suggesting that exercise improves mood, pain thresholds, and sleep (40, 41). One theory explaining the benefits of exercise proposes that exercise produces increases in serum levels of β-endorphin-like immunoreactivity, adrenocorticotropic hormone, prolactin, and growth hormone (42).
Relevant articles were located with a computer search of Medline and PsychLit from 1966 through January 2001. The following keywords were searched: unexplained physical symptoms, somatization, somatoform, psychogenic, functional somatic syndrome, irritable bowel, fibromyalgia, and chronic fatigue. These terms were cross-referenced with the keywords: treatment, therapy, and outcome. To ensure a comprehensive review of the literature, the reference lists of the articles generated from the above search were examined. Finally, we searched the Cochrane Library with these terms (43).
Studies were included in the review if they compared any psychosocial intervention with a comparison control intervention in the treatment of multiple unexplained physical symptoms. Clinical trials with patients suffering from single-symptom unexplained disorders, such as tension headaches or dysmenorrhea, were excluded from the review. Also excluded from the review were studies with mixed samples, that is, samples that comprised both single-symptom and polysymptomatic disorders. Only randomized experiments were included. Studies that were unpublished or published in a non-English language were excluded. These inclusion criteria produced 34 studies.
Estimating Treatment Effects
Whenever possible results were transformed into Cohen’s d as the measure of treatment effect size. Cohen’s d provides a standardized estimate of the mean differences among treatment groups (44). When group means, standard deviations, and sample sizes were unavailable, the statistical procedures described by Glass et al. (45) were used to estimate effect sizes.
Outcome measures of primary interest were those assessing intensity and frequency of physical symptoms. Because many studies examined changes in psychological and functional symptoms as well, effect sizes were calculated for each of these domains. Within these domains (ie, physical distress, psychological distress, and functional impairment), investigators often used multiple measures to examine outcomes. Effect sizes for each domain represent the mean effect size for the aggregated outcome measures within that domain.
Treatments for Somatization Disorder
Two groups of investigators have examined the effect of psychotherapy on patients with diverse unexplained physical symptoms (see Table 1). One study, using patients diagnosed with full somatization disorder, demonstrated that group psychotherapy reduced physical functioning and mental health complaints more than did standard medical care (46). The group treatment, which appeared to lack a theoretical basis, “aimed to enhance emotional expression, peer support, and coping skills.” The second trial, studying patients experiencing five or more unexplained physical symptoms, showed that individual CBT coincided with greater reductions in somatic complaints and physician visits than did standard medical care (47).
Treatments for Irritable Bowel Syndrome
Various psychosocial interventions for IBS have been examined in controlled trials. Table 2 summarizes each of them.
Four different therapeutic approaches have appeared more efficacious in reducing bowel symptoms than did the control intervention to which they were compared. Short-term dynamic therapy, hypnotherapy, progressive muscle relaxation, and cognitive therapy each seemed to reduce IBS symptoms (48–54). In these studies dynamic therapy, hypnotherapy, and progressive muscle relaxation were conducted individually, whereas cognitive therapy was conducted either individually (52, 53) or in a group format (54).
CBT has had mixed results in seven different controlled trials with IBS sufferers (55–61). Three trials showed CBT, administered individually, relieved bowel symptoms more effectively than did either standard medical care (55) or a waiting list (56, 57). In a fourth study, CBT administered as a group treatment resulted in greater improvements in IBS symptoms than did a waiting list control condition (58). Three other investigations found no difference between individual CBT and a control condition (59–61).
Only one study examined the efficacy of purely behavioral methods for IBS. In this study Corney et al. (62) compared a combination of bowel retraining, operant pain management techniques, and increasing activity levels to the standard medical treatment of bulking agents, antispasmodics, and laxatives. By the end of treatment, no differences were observed between the experimental and control groups in their reporting of IBS symptoms.
Treatments for Chronic Fatigue Syndrome
Psychosocial interventions, specifically CBT and exercise programs, have had mixed results in controlled trials with CFS patients (see Table 3). In one study CBT was no more effective than the control treatment (63), whereas in two other studies CBT reduced fatigue significantly more than the control treatments did (64, 65). Another trial found that a graded exercise program resulted in greater improvements in fatigue, functioning, and general health than did a relaxation/flexibility intervention (66). In a study comparing graded exercise, fluoxetine (a selective serotonin reuptake inhibitor), graded exercise plus fluoxetine, and a no-treatment control, neither exercise nor fluoxetine was associated with improvements in fatigue (67).
Treatments for Fibromyalgia
Numerous interventions for fibromyalgia have been subjected to empirical investigation (see Table 4).
Three trials compared the efficacy of a standard relaxation intervention to an alternative treatment. Hypnotherapy and EMG biofeedback each resulted in greater reductions in discomfort than did physical therapy (68) or false biofeedback (69), respectively. The third study, examining the effects of progressive muscle relaxation and hydrogalvanic baths, showed no difference between the two treatments; participants in each condition reported some pain relief (70).
The impact of exercise on fibromyalgia symptomatology has been examined by four groups of investigators. Two trials showed a thrice per week exercise group resulted in greater reductions in objective measures of tenderness than did a thrice per week flexibility training (71) or relaxation program (72). A third study evaluated the effects of four different interventions, specifically an exercise group, a relaxation group, a combined exercise/relaxation group, and an education/control group (73). In this study the exercise and exercise/relaxation groups experienced greater improvements in physical functioning than did the control group. Despite there being no differences among the four groups’ myalgia scores or self-reports of pain, all three treatment groups manifested greater decreases in tenderness than the control group did (73). The fourth trial failed to demonstrate reductions in self-reported pain from an exercise treatment relative to a no-treatment control condition (74).
The efficacy of group CBT, but not individual CBT, for fibromyalgia has been assessed in three trials. Two trials comparing a CBT/education group with a discussion/education group found no differences in pain complaints or functioning between the two treatment conditions (75, 76). The third trial, comparing the efficacy of a group CBT to that of an autogenic training group, also showed no differences between the conditions at posttreatment. However, 4 months later the CBT participants reported a greater reduction in pain intensity than the relaxation participants did (77).
Finally, two groups of investigators have compared the efficacy of stress management interventions with exercise treatments. One study examined an exercise group, a stress management group, and standard medical care. Just after treatment, both the stress management and exercise participants reported greater reductions in tenderness than the control participants. The investigators found no differences between the stress management and exercise groups just after treatment nor 4 years later (78). In another study, participants were randomly assigned to a stress management program, a stress management plus exercise program, or a waiting list (79). Immediately after treatment, there were no differences among any of the groups’ reports of pain (79).
Aggregating the Studies
The majority of studies suggest that psychosocial interventions provide some benefit to polysymptomatic somatizers. Twenty-two of the 33 (67%) studies, using change in physical symptoms as the primary outcome measure, reported the treatment group improved significantly more than the control group did. Similarly, 8 of the 10 (80%) investigators, assessing efficacy with physical functioning scores, found the experimental intervention outperformed the control intervention. Eight of the 17 (47%) trials evaluating the impact of treatment on psychological distress showed greater improvement in the experimental group than in the control group.
Multiple Fisher’s exact analyses were performed to determine whether any of the following variables was associated with treatment outcome: patient’s diagnosis (IBS vs. CFS vs. fibromyalgia vs. somatization), type of treatment (CBT vs. relaxation vs. exercise), format of treatment (individual vs. group), and type of control condition (no or minimal treatment vs. attention-control treatment). None of these analyses yielded significant results. Of course, given the small effect sizes in these analyses, none of the analyses had sufficient power to reject the null hypothesis definitively. For example, the statistical power was only 11% for the analysis of treatment outcome by type of control condition.
To calculate the magnitude of the interventions’ impact, effect sizes were examined. Eleven studies reported sufficient data to calculate effect sizes. In these studies, effect sizes ranged from 0.20 (for dynamic therapy vs. standard medical care for IBS patients) (49) to 4.01 (for EMG biofeedback vs. false EMG biofeedback for fibromyalgia patients) (69). The mean effect size for these 11 studies, weighted by sample size, is 0.68.
The number of participants experiencing clinically meaningful improvement is often calculated to demonstrate a treatment’s effect on individual participants. Clinically significant change was defined a priori in 11 studies, 9 of those addressing IBS. The percentage of experimental patients that achieved clinically significant change ranged from 44% to 80%, as compared with 25% to 55% of pseudotreatment patients and 0% to 32% of inactive control patients.
Follow-up assessments were conducted with both treatment and control participants in nine trials. Seven of the nine studies showed treatment gains had been maintained or enhanced at the follow-up evaluation. The two studies resulting in no long-term differences between treatment and control patients had also shown no differences at the posttreatment evaluation. The time frame of follow-up assessments ranged from 3 to 12 months with a mean of 6.4 months.
Participants in the trials were usually treated in tertiary care centers. Almost half of the studies (16 of 34) accepted referrals only from specialists, such as gastroenterologists or rheumatologists. Three investigators (9%) treated primary care or internal medicine patients; one investigator conducted treatment in the primary care setting. The remaining studies either failed to report their referral sources or recruited patients from a variety of sources (ie, from various types of physicians, advertisements, patient organizations, and support groups).
Our decision to aggregate the research on IBS, CFS, fibromyalgia, and somatization disorder may invite controversy. Many medical specialists, focusing on the bodily organ or system of their specialization, assume these disorders have distinct pathophysiological causes and distinguish among these syndromes. Other investigators have suggested these syndromes be viewed as one disorder. Despite the disputes over the biological mechanisms involved, all agree there is significant overlap in these patients’ behaviors, beliefs regarding their condition, and psychological functioning (17–19). Polysymptomatic somatizers tend to adopt the sick role (80) by overutilizing health care and withdrawing from their activities. Assuming their symptoms are signs of a serious, disabling illness that is likely to worsen, these individuals often think catastrophically about their health. Also, they frequently suffer from emotional disorders (17–19).
Grouping IBS, CFS, fibromyalgia, and somatization disorder into one category, termed polysymptomatic somatization, has a number of implications. First, such classification highlights the importance of environmental, behavioral, and psychological factors. Second, this classification implies that a biopsychosocial model is superior to a biological model in the understanding and treatment of these patients.
The theories underlying the interventions assessed in this review are predicated on a biopsychosocial model. Although each approach has its own distinct rationale, the similarities of the rationales and treatments should be noted. None of the theories nor their associated treatments is organ-specific. Instead, it is assumed that any one or more organs can be affected by various psychosocial processes. Each intervention encourages the patient to make changes in thinking and/or conduct.
On the whole, this review suggests psychosocial treatments may be modestly effective in reducing the physical discomfort and disability of polysymptomatic somatizers. Benefits may last for at least 3 months after treatment has ended. No one intervention seems more potent than the others. None of the syndromes seems more responsive to such interventions than the others. The conclusions must be tempered with a few caveats. First, because only one study has been published on full somatization disorder, as defined in DSM, little is known about treatment efficacy with this population. Second, methodological shortcomings are present in much of the literature, rendering all conclusions uncertain. These methodological weaknesses will be discussed below.
A chief criticism of the literature is the paucity of intent-to-treat analyses conducted. Often investigators excluded premature withdrawals from the data analysis, resulting in biased findings. Nineteen studies reported either using intent-to-treat analyses or having no premature withdrawals. Both of the somatization and four (80%) of the CFS studies reported findings using intent-to-treat analyses. Only 3 of the 12 fibromyalgia investigators handled premature withdrawals properly; one other fibromyalgia trial had no dropouts. Intent-to-treat analyses were not used in any of the IBS trials, of which 10 (67%) reported premature withdrawals. Thus, the effect sizes from the IBS and fibromyalgia literature are debatable and may have been overestimated.
The mean effect size across studies was 0.68. This effect size is based on data from only 11 trials, 3 of which failed to use intent-to-treat analyses. Given that data from so few trials were included in this calculation, interpretation is problematic. To raise additional questions about the effect size, only published studies have been included in this review. If one assumes that additional studies on psychosocial interventions have not been published because of their negative findings (ie, the file drawer effect), one must assume the true effect size to be lower than 0.68.
Even if a large effect size had been observed, the practical utility of these treatments would still be uncertain. Large effect sizes convey little information about individuals’ responses to an intervention. For instance, it is possible for investigators using large samples, for example, Svedlund et al. (49), to detect a statistical difference without achieving clinically significant change in any participant. Researchers have not uniformly assessed whether psychosocial treatments have a clinically meaningful impact on individual subjects. Only one CFS, one fibromyalgia, and no somatization studies examined clinical significance. The nine IBS studies assessing clinically meaningful improvement suggest the effect of the active treatment was modest relative to that of the control treatment. Changes in illness behavior, such as use of medical services and absenteeism from work, are other “clinically meaningful” measures of change that should also be reported in future studies.
Long-term follow-up assessments are critical in determining the efficacy of any intervention. The finding that a substantial number of control participants experienced improvements at the post-treatment evaluation (59–62, 70) implies that a placebo response may have occurred. Given that the benefits placebo responders derive from treatment may disappear during the follow-up period, such follow-up may help distinguish placebo treatments from active treatments. Also, practically effective treatments should be enduring in their impact. If treated patients return to their former levels of functioning within a year of treatment, the value of these interventions is limited. Although most of the reviewed trials reporting follow-up data support the long-term efficacy of psychosocial treatments, too often follow-up data have been incomplete or nonexistent. Only 26% of the trials reported long-term assessment data for both control and treated patients.
Despite the high rates of emotional distress experienced by polysymptomatic somatizers, the impact of treatment on psychiatric symptoms has not been adequately addressed. Two investigators excluded participants who met DSM criteria for a psychiatric disorder (66, 76). Only half of the investigators measured changes in psychiatric symptoms as a secondary outcome variable. Although many trials showed that emotional and physical symptoms improved concurrently (48, 52, 53, 65), others reported no association between the changed physical and emotional symptoms (49, 50, 71). Additional research is needed to determine whether psychiatric symptomatology mediates the relationship between psychosocial treatments and unexplained physical symptoms. One review has already concluded that no such mediation exists for CBT. Examining only CBT trials for somatizers, Kroenke and Swindle (9) found that psychiatric symptoms often failed to benefit from CBT even when physical symptoms did. The present review’s failure to show such a clear distinction between the impact of psychosocial treatments on psychiatric, relative to physical, symptoms may be attributable to the broader range of interventions reviewed here.
Unexplained physical symptoms may be ameliorated by many active or control treatments. The authors of the studies showing no difference between the experimental and control conditions noted that participants in both the experimental and control groups improved significantly over time (59–62, 70). Different psychosocial interventions seem to have similar effects on patients’ symptoms. Taken together, these findings suggest that none of the treatments alters specific dysfunctions, but instead the treatments include some common factor or factors that benefit these patients. The active component(s) of treatment may be the patient’s expectation of improvement, attention from a healthcare provider, or encouragement to resume healthy functioning. Alternatively, it is possible that the treatments relieve feelings of helplessness, hopelessness, depression, and/or anxiety, which may promote a reduction in physical discomfort. Future research should explore the mechanism of change associated with these treatments.
Few investigators examined the acceptability of their treatment to the general somatization population. Most trials were advertised for and conducted in tertiary care centers instead of in the primary care clinics where these patients typically are treated. The number of patients screened and refusing treatment as well as the number of missed treatment sessions frequently were not reported. Because most somatizing patients attribute their discomfort to medical illnesses and seek medical treatment, patients treated in psychiatric clinics may not adequately represent the population. Thus, the generalizability of the findings is uncertain.
Two previous reviews of psychosocial treatment studies have been conducted with patient populations that are similar to ours. After systematically evaluating the quality as well as the content of psychosocial treatment trials for IBS, Talley et al. (6) state that the efficacy of these treatments has not yet been established because of the literature’s methodological weaknesses. In a separate review summarizing only CBT trials with patients diagnosed with one or more unexplained physical symptoms, Kroenke and Swindle (9) found CBT to be effective in reducing physical discomfort. The discrepancies between these conclusions may be a function of not only the populations and interventions reviewed but also the authors’ criteria. Talley et al.’s review (6) is somewhat more methodologically stringent than Kroenke and Swindle’s review (9) in that the former found only one study that met their standard of “methodological acceptability.”
The present review suggests that psychosocial treatments, although seemingly beneficial, have not yet been shown to have a lasting and clinically meaningful influence on the physical complaints of polysymptomatic somatizers. To demonstrate unequivocal support of a treatment, investigators should report effect sizes using intent-to-treat analyses, the number of patients experiencing clinically significant change, and long-term follow-up results. At present, the methodologically sound studies suggest the interventions may lack potency. Future research should assess the efficacy of more intensive treatments. No investigator examined an intervention requiring more than 16 sessions, and most interventions lasted only 6 to 12 sessions. Such brief treatment is in vogue as third-party payers limit coverage of long-term treatment. Chronic somatic complaints, however, may require treatment of a duration longer than 2 months.
This work was supported by Grants K08 MH01662 and R01 MH60265 from the National Institute of Mental Health.
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somatization; irritable bowel syndrome; chronic fatigue syndrome; fibromyalgia; treatment
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