Practitioner Review: Neurobiological consequences of childhood maltreatment - clinical and therapeutic implications for practitioners

BACKGROUND

Childhood maltreatment is one of the most important preventable risk factors for a wide variety of psychiatric disorders. Further, when psychiatric disorders emerge in maltreated individuals they typically do so at younger ages, with greater severity, more psychiatric comorbid conditions, and poorer response to established treatments, resulting in a more pernicious course with an increased risk for suicide. Practitioners treating children, adolescents, and young adults with psychiatric disorders will likely encounter the highest prevalence of clients with early-onset maltreatment-associated psychiatric disorders. These may be some of their most challenging cases.

METHOD

In this report, we explore key validated alterations in brain structure, function, and connectivity associated with exposure to childhood maltreatment as potential mechanisms behind their patients' clinical presentations.

RESULTS

We then summarize key behavioral presentations likely associated with neurobiological alterations and propose a toolkit of established trauma and skills-based strategies that may help diminish symptoms and foster recovery. We also discuss how some of these alterations may serve as latent vulnerability factors for the possible development of future psychopathology.

CONCLUSIONS

Research on the neurobiological consequences of childhood adversity provides a vastly enriched biopsychosocial understanding of the developmental origins of health and pathology that will hopefully lead to fundamental advances in clinical psychology and psychiatry.

Annual Research Review: Enduring neurobiological effects of childhood abuse and neglect

BACKGROUND

Childhood maltreatment is the most important preventable cause of psychopathology accounting for about 45% of the population attributable risk for childhood onset psychiatric disorders. A key breakthrough has been the discovery that maltreatment alters trajectories of brain development.

METHODS

This review aims to synthesize neuroimaging findings in children who experienced caregiver neglect as well as from studies in children, adolescents and adults who experienced physical, sexual and emotional abuse. In doing so, we provide preliminary answers to questions regarding the importance of type and timing of exposure, gender differences, reversibility and the relationship between brain changes and psychopathology. We also discuss whether these changes represent adaptive modifications or stress-induced damage.

RESULTS

Parental verbal abuse, witnessing domestic violence and sexual abuse appear to specifically target brain regions (auditory, visual and somatosensory cortex) and pathways that process and convey the aversive experience. Maltreatment is associated with reliable morphological alterations in anterior cingulate, dorsal lateral prefrontal and orbitofrontal cortex, corpus callosum and adult hippocampus, and with enhanced amygdala response to emotional faces and diminished striatal response to anticipated rewards. Evidence is emerging that these regions and interconnecting pathways have sensitive exposure periods when they are most vulnerable.

CONCLUSIONS

Early deprivation and later abuse may have opposite effects on amygdala volume. Structural and functional abnormalities initially attributed to psychiatric illness may be a more direct consequence of abuse. Childhood maltreatment exerts a prepotent influence on brain development and has been an unrecognized confound in almost all psychiatric neuroimaging studies. These brain changes may be best understood as adaptive responses to facilitate survival and reproduction in the face of adversity. Their relationship to psychopathology is complex as they are discernible in both susceptible and resilient individuals with maltreatment histories. Mechanisms fostering resilience will need to be a primary focus of future studies.

Childhood maltreatment and psychopathology: A case for ecophenotypic variants as clinically and neurobiologically distinct subtypes

OBJECTIVE

Childhood maltreatment increases risk for psychopathology. For some highly prevalent disorders (major depression, substance abuse, anxiety disorders, and posttraumatic stress disorder) a substantial subset of individuals have a history of maltreatment and a substantial subset do not. The authors examined the evidence to assess whether those with a history of maltreatment represent a clinically and biologically distinct subtype.

METHOD

The authors reviewed the literature on maltreatment as a risk factor for these disorders and on the clinical differences between individuals with and without a history of maltreatment who share the same diagnoses. Neurobiological findings in maltreated individuals were reviewed and compared with findings reported for these disorders.

RESULTS

Maltreated individuals with depressive, anxiety, and substance use disorders have an earlier age at onset, greater symptom severity, more comorbidity, a greater risk for suicide, and poorer treatment response than nonmaltreated individuals with the same diagnoses. Imaging findings associated with these disorders, such as reduced hippocampal volume and amygdala hyperreactivity, are more consistently observed in maltreated individuals and may represent a maltreatment-related risk factor. Maltreated individuals also differ from others as a result of epigenetic modifications and genetic polymorphisms that interact with experience to increase risk for psychopathology.

CONCLUSIONS

Phenotypic expression of psychopathology may be strongly influenced by exposure to maltreatment, leading to a constellation of ecophenotypes. While these ecophenotypes fit within conventional diagnostic boundaries, they likely represent distinct subtypes. Recognition of this distinction may be essential in determining the biological bases of these disorders. Treatment guidelines and algorithms may be enhanced if maltreated and nonmaltreated individuals with the same diagnostic labels are differentiated.

Increased Gsα within blood cell membrane lipid microdomains in some depressive disorders: an exploratory study

The stimulatory guanine nucleotide binding protein Gs couples many cellular receptors to adenylate cyclase, and the Gsα subunit activates all 9 isoforms of the adenylate cyclase catalytic unit to produce the enzyme product cyclicAMP or cAMP. In prefrontal cortex and cerebellum of unipolar depressive suicides, Rasenick and colleagues have found increased concentrations of Gsα in membrane lipid microdomains (Donati et al., 2008), where the ensconced Gsα is less likely to activate adenylate cyclase by receptor and postreceptor pathways (Allen et al., 2005, 2009). We report that a group of 7 depressed patients (DP-1) had (1) reduced activation of platelet receptor-stimulated adenylate cyclase by both prostaglandins E2 and D2 compared to controls, and (2) reduced postreceptor stimulation of adenylate cyclase by aluminum fluoride ion in both platelets and mononuclear leukocytes when compared to both another group of depressed patients (DP-2, n = 17) and to controls (n = 21). Our observations in the blood cells of the group DP-1 support the findings of Donati et al. (2008), and they reflect the importance of this interaction between the activated Gsα subunit and membrane lipid microdomains in the pathophysiology and treatment of some major depressive disorders.

Hurtful words: association of exposure to peer verbal abuse with elevated psychiatric symptom scores and corpus callosum abnormalities

OBJECTIVE

Previous studies have shown that exposure to parental verbal abuse in childhood is associated with higher rates of adult psychopathology and alterations in brain structure. In this study the authors sought to examine the symptomatic and neuroanatomic effects, in young adulthood, of exposure to peer verbal abuse during childhood.

METHOD

A total of 848 young adults (ages 18-25 years) with no history of exposure to domestic violence, sexual abuse, or parental physical abuse rated their childhood exposure to parental and peer verbal abuse and completed a self-report packet that included the Kellner Symptom Questionnaire, the Limbic Symptom Checklist-33, and the Dissociative Experiences Scale. Diffusion tensor images were collected for a subset of 63 young adults with no history of abuse or exposure to parental verbal abuse selected for varying degrees of exposure to peer verbal abuse. Images were analyzed using tract-based spatial statistics.

RESULTS

Analysis of covariance revealed dose-dependent effects of peer verbal abuse on anxiety, depression, anger-hostility, dissociation, "limbic irritability," and drug use. Peer and parental verbal abuse were essentially equivalent in effect size on these ratings. Path analysis indicated that peer verbal abuse during the middle school years had the most significant effect on symptom scores. Degree of exposure to peer verbal abuse correlated with increased mean and radial diffusivity and decreased fractional anisotropy in the corpus callosum and the corona radiata.

CONCLUSIONS

These findings parallel results of previous reports of psychopathology associated with childhood exposure to parental verbal abuse and support the hypothesis that exposure to peer verbal abuse is an aversive stimulus associated with greater symptom ratings and meaningful alterations in brain structure.

Length of time between onset of childhood sexual abuse and emergence of depression in a young adult sample: a retrospective clinical report

OBJECTIVE

Depression is the most common adult outcome of exposure to childhood sexual abuse (CSA). In this study, we retrospectively assessed the length of time from initial abuse exposure to onset of a major depressive episode.

METHOD

A community-based survey of childhood experiences in 564 young adults aged 18 to 22 years, conducted between 1997 and 2001, identified 29 right-handed female subjects with CSA but no other exposure to trauma. Subjects were interviewed for lifetime history and age at onset of Axis I disorders using the Structured Clinical Interview for DSM-IV Axis I Disorders.

RESULTS

Sixty-two percent (N = 18) of the sexual abuse sample met full lifetime criteria for major depressive disorder. Episodes of depression emerged a mean +/- SD of 9.2 +/- 3.6 years after onset of exposure to sexual abuse. Mean survival time from onset of abuse to onset of depression for the entire sample was 11.47 years (95% CI = 9.80 to 13.13 years). There was a surge in new cases between 12 and 15 years of age. Mean +/- SD time to onset of posttraumatic stress disorder was 8.0 +/- 3.9 years.

CONCLUSIONS

Exposure to CSA appears to sensitize women to the development of depression and to shift age at onset to early adolescence. Findings from this formative study suggest that clinicians should not interpret the absence of symptoms at the time of CSA as a sign of resilience. Continued monitoring of victims of CSA as they pass through puberty is recommended. Reasons for the time lag between CSA and depression are proposed along with potential strategies for early intervention.

Enhanced norepinephrine output during long-term desipramine treatment: a possible role for the extraneuronal monoamine transporter (SLC22A3)

To study the delay (2-6 weeks) between initial administration of norepinephrine reuptake inhibitor antidepressants and onset of clinical antidepressant action, we examined the effects of desipramine treatment on urinary and plasma catecholamines and their metabolites during the initial 6 weeks of treatment in depressed patients. Catecholamines and metabolites in 24-h urine collections and 8:00 a.m. plasma samples were measured at baseline and after 1, 4, and 6 weeks of desipramine treatment. Desipramine treatment produced significant increases in urinary norepinephrine (NE) and normetanephrine (NMN) and plasma NE at Weeks 4 and 6, but not at Week 1. The ratio of urinary NE/NMN was increased at Weeks 4 and 6, suggesting a reduction in the metabolism of NE to NMN at extraneuronal sites by Weeks 4 and 6. The increases in urinary NE and NMN and plasma NE at Weeks 4 and 6 of desipramine treatment were associated with a reduction in the conversion of NE to NMN. This would be compatible with a blockade of the extraneuronal monoamine transporter (organic cation transporter 3; SLC22A3) by NMN. Inhibition of the extraneuronal monoamine transporter may be an important component in the clinical pharmacology of the norepinephrine reuptake inhibitor antidepressant drugs, such as desipramine.

Sticks, stones, and hurtful words: relative effects of various forms of childhood maltreatment

OBJECTIVE

Childhood maltreatment is an important psychiatric risk factor. Research has focused primarily on the effects of physical abuse, sexual abuse, or witnessing domestic violence. Parental verbal aggression has received little attention as a specific form of abuse. This study was designed to delineate the impact of parental verbal aggression, witnessing domestic violence, physical abuse, and sexual abuse, by themselves and in combination, on psychiatric symptoms.

METHOD

Symptoms and exposure ratings were collected from 554 subjects 18-22 years of age (68% female) who responded to advertisements. The Verbal Abuse Questionnaire was used to assess exposure to parental verbal aggression. Outcome measures included dissociation and symptoms of "limbic irritability," depression, anxiety, and anger-hostility. Comparisons were made by using effect sizes.

RESULTS

Verbal aggression was associated with moderate to large effects, comparable to those associated with witnessing domestic violence or nonfamilial sexual abuse and larger than those associated with familial physical abuse. Exposure to multiple forms of maltreatment had an effect size that was often greater than the component sum. Combined exposure to verbal abuse and witnessing domestic violence had a greater negative effect on some measures than exposure to familial sexual abuse.

CONCLUSIONS

Parental verbal aggression was a potent form of maltreatment. Exposure to multiple forms of abuse was associated with very large effect sizes. Most maltreated children had been exposed to multiple types of abuse, and the number of different types is a critically important factor.

Diabetes, the brain, and behavior: is there a biological mechanism underlying the association between diabetes and depression?

In summary, our review of the literature suggests that diabetes, especially type 1 diabetes, may place patients at risk for a depressive disorder through a biological mechanism linking the metabolic changes of diabetes to changes in brain structure and function. Further studies are warranted examining these relationships in order to better understand the impact of diabetes on brain functioning and structure as well as one potential manifestation of such changes--affective disorder. Moreover, such studies could play a useful role in better understanding mechanisms that commonly underlie the development of depression in individuals without diabetes but with other medical problems or conditions.

Glycemic control and major depression in patients with type 1 and type 2 diabetes mellitus

The current study evaluated the association of glycemic control and major depression in 33 type 1 and 39 type 2 diabetes mellitus patients. Type 1 patients with a lifetime history of major depression showed significantly worse glycemic control than patients without a history of psychiatric illness (t = 2.09; df = 31, p < 0.05). Type 2 diabetes patients with a lifetime history of major depression did not have significantly worse control than those with no history of psychiatric illness. Findings from this study indicate different relationships between lifetime major depression and glycemic control for patients with type 1 and type 2 diabetes. Treatment implications for glycemic control in type 1 and type 2 diabetes patients are discussed.

Hypothalamic-pituitary-adrenal axis effects on plasma homovanillic acid in man

BACKGROUND

Effects of the hypothalamic-pituitary-adrenal (HPA) axis on central dopaminergic systems have been proposed to underlie the development of psychotic symptoms in depression. This study examined HPA axis hormone effects on plasma levels of homovanillic acid (HVA), the dopamine metabolite, in healthy volunteers, using a placebo-controlled, double-blind, random-assignment, crossover design. On the basis of preliminary studies, we hypothesized that HPA axis hormones would produce delayed effects on plasma HVA levels measured in the afternoon.

METHODS

Ten healthy subjects underwent a standard protocol on four occasions and each time received ovine corticotropin-releasing hormone, synthetic adrenocorticotropic hormone (ACTH), cortisol, or placebo. Plasma HVA was measured at 9 AM and 4 PM on Day 1, immediately prior to administration of the test substance at 7 PM, then at 30-60-min intervals until 11 PM. Plasma HVA levels were subsequently obtained at 9 AM and 4 PM on Days 2 and 3.

RESULTS

As predicted, there were significant differences between test substances in delayed effects on afternoon HVA levels measured on Days 2 and 3, with cortisol and ACTH producing greater increases in HVA than placebo. Acute effects of HPA axis hormones on HVA were not found, while differences between test substances in delayed effects on morning HVA levels approached significance.

CONCLUSIONS

HPA axis hormones exert delayed effects on plasma HVA levels in healthy humans.

Signal transduction by platelet adenylate cyclase: alterations in depressed patients may reflect impairment in the coordinated integration of cellular signals (coincidence detection)

BACKGROUND

Adenylate cyclase (AC) responds to distinct but coincident signals from the agonist-stimulated G-protein Gs and the inhibitory G-protein Gi by generating a greater output signal-to-noise ratio--i.e., agonist-stimulated to basal ratio (fold-stimulation)--through coincidence detection than that generated by a single input (Gs) alone. Such coincidence detection by murine brain AC was found to be enhanced during chronic antidepressant treatment with imipramine.

METHODS

We examined and compared the basal, agonist-stimulated, and guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) or AlF4 ion postreceptor-stimulated AC activities in mononuclear leukocytes and platelets from the same blood specimens obtained from depressed patients (n = 27) and control subjects (n = 19).

RESULTS

In all subjects, the differences (delta GTP gamma S or delta AlF4) between postreceptor measures of AC in mononuclear leukocytes (where AC is regulated by Gs but not by Gi) and platelets (where AC is regulated by both Gs and Gi) were highly significant. In controls, the relationships between delta GTP gamma S or delta AlF4 and basal, agonist-stimulated, and the fold-stimulation of agonist-stimulated platelet AC resembled the regulation of AC by Gi in model-membrane systems. Comparable relationships between delta GTP gamma S or delta AlF4 and basal, agonist-stimulated, and the fold-stimulation of agonist-stimulated platelet AC activities were not observed in depressed patients.

CONCLUSIONS

Our results suggest that in controls, platelet AC enzyme activity is determined (in part) by the coordinated integration of signals from Gs and Gi through coincidence detection, while such coincidence detection by platelet AC may be impaired in patients with depressive disorders.

McLean Hospital depression research facility: early-onset phobic disorders and adult-onset major depression

BACKGROUND

This study explores the temporal relationship between anxiety and major depressive disorders in a cohort of patients with current major depression.

METHOD

Current prevalence and lifetime history of specific anxiety disorders were assessed using the Structured Clinical Interview for DSM-III-R Diagnosis (SCID-P) in 85 patients with DSM-III-R major depression. Consensus DSM-III-R diagnoses were assigned by at least two psychiatrists or psychologists.

RESULTS

Twenty-nine per cent met criteria for at least one current anxiety disorder and 34% had at least one anxiety disorder at some point in their lives. The mean (s.d.) age of onset of anxiety disorder in the depressed patients with comorbid social or simple phobia (15 (9) years) was significantly younger than was that of their major depression (25 (9) years). In contrast, the mean (s.d.) age of onset of anxiety in patients with comorbid panic or OCD (20 (8) years) was similar to that seen for their major depression (21 (9) years). In patients with major depression with comorbid anxiety disorders, both the social phobia (10 of 13) and simple phobia (4 of 4) were more commonly reported to start at least two years prior to their major depression in contrast to depressives with comorbid panic (3 of 10 subjects)-Fisher's exact test, P = 0.01.

CONCLUSIONS

Early-onset social and simple phobias appear to be risk factors for later onset of major depression.

Revisiting the factor structure for positive and negative symptoms: evidence from a large heterogeneous group of psychiatric patients

OBJECTIVE

The factor structures of individual positive and negative symptoms as well as global ratings were examined in a diagnostically heterogeneous group of subjects.

METHOD

Subjects were identified through a clinical and family study of patients with major psychoses at a VA medical center and evaluated with the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms. For the examination of global-level factor structures (N = 630), both principal-component analysis and factor analysis with orthogonal rotation were used. Factor analysis was used for the examination of item-level factor structures as well (N = 549).

RESULTS

The principal-component analysis of global ratings revealed three factors: negative symptoms, positive symptoms, and disorganization. The factor analysis of global ratings revealed a negative symptom factor and a positive symptom factor. The item-level factor analysis revealed two negative symptom factors (diminished expression and disordered relating), two positive symptom factors (bizarre delusions and auditory hallucinations), and a disorganization factor.

CONCLUSIONS

The generation of additional meaningful factors at the item level suggests that important information about symptoms is lost when only global ratings are viewed. Future work should explore clinical and pathological correlates of the more differentiated item-level symptom dimensions.

The effects of psychiatric disorders and symptoms on quality of life in patients with type I and type II diabetes mellitus

The purpose of this study was to evaluate the influence of psychiatric symptoms and illness status on the health-related quality of life (HRQOL) of out-patients with Type I and Type II diabetes mellitus. Using a two-stage design, all patients were assessed by two measures of quality of life (Diabetes Quality of Life Measure; Medical Outcome Study Health Survey) and a psychiatric symptoms checklist (SCL-90R). Patients scoring 63 or greater on the global severity index of the SCL-90R and 30% below this cutoff were then evaluated using the Structured Clinical Interview for the DSM-III-R (SCID). Quality of life in both Type I and Type II diabetes was influenced by the level of current psychiatric symptoms and presence of co-morbid psychiatric disorder, after controlling for number of diabetic complications (e.g. effect of lifetime psychiatric illness on diabetes-related HRQOL; F = 46.8; df = 3, 135; p < 0.005). These effects were found consistently across specific domains. Both recent and past psychiatric disorders influenced HRQOL. Separate analyses comparing patients with and without depression showed similar effects. No interaction effects between diabetes type, number of complications, and psychiatric status were found in analyses. Finally, increased severity of psychiatric symptoms was correlated with decreased HRQOL in patients without current, recent, or past psychiatric diagnosis. This study shows the consistent, independent contribution of psychiatric symptoms and illness to the HRQOL of patients with a co-existing medical illness. Thus, psychiatric interventions addressing common conditions, such as depression, could improve the HRQOL of patients without changing medical status.

Diurnal variation of plasma cortisol and homovanillic acid in healthy subjects

We investigated the relationship between plasma levels of cortisol, the dopamine metabolite homovanillic acid (HVA) and norepinephrine in healthy human subjects. Plasma cortisol and HVA levels were measured at 0800h, and in an integrated sampling procedure involving samples every 15 min between 1300 and 1600h. Plasma norepinephrine was measured at 0800 and 1300h. Cortisol, HVA and norepinephrine indices did not show significant correlations with each other. Both cortisol and HVA showed significant decreases over time. Longitudinal Random Effects (LRE) models were used to test whether individual cortisol and HVA curves over time were correlated; significant correlations were not found with this procedure. While significant correlations between cortisol and catecholamine indices have been reported in depressed patients, our results do not suggest such correlations in healthy subjects.

Platelet monoamine oxidase activity and deficit syndrome schizophrenia

Measures of affective flattening that combine self-reported emotional experience with observed affect may identify deficit syndrome patients better than ratings based on observed affect alone. In this study, we examined 23 clinically stable but chronically ill schizophrenic patients, 15 of whom were found to have a deficit syndrome. After exclusion of patients with self-reported depressed mood from the deficit syndrome group, the remaining patients with a deficit syndrome not accompanied by self-reported depressed mood showed a strikingly homogeneous distribution of platelet monoamine oxidase activity. Results suggest that inclusion of self-reported emotional experience in clinical definitions of the deficit syndrome will increase the specificity of diagnosis.

Ten-year outcome of tardive dyskinesia

OBJECTIVE

The purpose of this study was to assess the long-term outcome of patients with tardive dyskinesia.

METHOD

A group of 122 neuroleptic-treated Hungarian outpatients were assessed for tardive dyskinesia on the Abnormal Involuntary Movement Scale and the Tardive Dyskinesia Rating Scale by the same rater over a 10-year period.

RESULTS

Sixty-three of the patients received both 5- and 10-year follow-up assessments and are the subjects of this report. The overall prevalence of tardive dyskinesia in this group changed little over time; it was 30.2% at baseline, 36.5% at 5 years, and 31.7% at 10 years. However, there were changes in the tardive dyskinesia status of individual patients; 11 patients had remissions, and 12 who did not have tardive dyskinesia at the baseline assessment had developed it by the 10-year assessment. These two subgroups did not differ significantly on demographic and drug history variables. Outcome of tardive dyskinesia was not significantly related to neuroleptic treatment or to age.

CONCLUSIONS

The data of this 10-year follow-up study provide evidence for the long-term stability of tardive dyskinesia and for the feasibility of maintenance neuroleptic therapy for chronic psychotic patients who have tardive dyskinesia.

The evaluation of two measures of quality of life in patients with type I and type II diabetes

OBJECTIVE

To examine the effects of type I and type II diabetes on patient perceptions of their quality of life and compare the psychometric properties of a generic versus a diabetes-specific quality of life measure.

RESEARCH DESIGN AND METHODS

Consecutive outpatients (n = 240) from a large multispecialty diabetes clinic were studied on a single occasion using two measures of quality of life--Diabetes Quality of Life Measure (DQOL) and the Medical Outcome Study Health Survey 36-Item Short Form (SF-36). No interventions were performed. This study examines three issues: 1) the reliability (internal consistency) of the two measures; 2) the relationship between the DQOL and SF-36 scales; and 3) the influence of clinical patient characteristics, such as number and severity of diabetes complications, on quality of life. Examination of this issue provides information about the construct validity of the two quality of life measures.

RESULTS

The estimates of internal consistency (Cronbach's alpha) for the DQOL and SF-36 subscales ranged from 0.47 to 0.97. These values were very similar to the published findings from previous studies. The subscales of the two measures were variably correlated with one another (range of correlations: -0.003 to 0.60), indicating that the areas of functioning addressed by the DQOL and SF-36 overlapped only to a modest degree. Examination of the relationship of demographic factors to the DQOL measures suggests that they are not generally confounded by factors such as education, sex, or duration of diabetes. Health-related quality of life is affected by the marital status of both type I and type II diabetic patients, with separated and divorced individuals generally experiencing lower levels of quality of life. The quality of life measures were sensitive to clinical characteristics, such as frequency and severity of complications. Even after factors such as marital status and, among type II diabetic patients, type of treatment, patients' severity of diabetes complications was a significant predictor of both the diabetes-related and the more broad-based measure of quality of life. For type II diabetic patients, insulin treatment was associated with lower levels of satisfaction with diabetes and greater impact of diabetes on quality of life.

CONCLUSIONS

This study provides evidence for the reliability and validity of two measures of quality of life. The two measures examine quality of life from different but complimentary perspectives. The DQOL seems more sensitive to lifestyle issues and contains special questions and worry scales oriented toward younger patients, whereas the SF-36 provides more information about functional health status. Thus, the measures may be used usefully in combination in studies of both type I and type II diabetic patients.