Resemblance in physical activity levels: The Portuguese sibling study on growth, fitness, lifestyle, and health.

OBJECTIVES: To investigate the relationships of biological, behavioral, familial, and environmental characteristics with siblings´ physical activity (PA) levels as well as the intrapair resemblance in PA. METHODS: The sample comprises 834 (390 females) biological siblings [brother-brother (BB), sister-sister (SS), brother-sister (BS)] aged 9 to 20 years. Total PA index (TPAI) was estimated by questionnaire. Information on potential behavioral, familial, and environmental correlates was obtained by self-report; body mass index (BMI), biological maturation, and physical fitness were measured. Multilevel models were used to analyze siblings´ clustered data, and sibling resemblance was estimated with the intraclass correlation (ρ). RESULTS: On average, younger sibs, those more physically fit, and those with more parental support had greater TPAI. Further, BB pairs had higher TPAI levels than SS or BS pairs, but also had greater within-pair variance. When adjusted for all covariates, SS pairs demonstrated greater resemblance in TPAI (ρ = 0.53, 95%CI = 0.38-0.68) than BS (ρ = 0.26, 95%CI = 0.14-0.43) or BB pairs (ρ = 0.18, 95%CI = 0.06-0.44). CONCLUSIONS: Age, physical fitness, and parental support were the best predictors of TPAI levels. A moderate level of resemblance in TPAI was observed in SS pairs, while lower resemblance was found for BS and BB pairs. These findings may be due to differences in the roles of shared genetic factors, familial, and environmental characteristics across different sibling types.

Correlates of children's compliance with moderate-to-vigorous physical activity recommendations: a multilevel analysis.

This study aimed to investigate the association between individual and school characteristics associated with the number of school days children comply with moderate-to-vigorous physical activity (MVPA) recommendations. Sample comprises 612 Portuguese children, aged 9-11 years, from 23 schools. Time spent in MVPA was measured by accelerometry, while individual-level correlates were obtained by anthropometry and questionnaires. School-level variables were collected by questionnaire, and accelerometer wear time and season were also considered. Maximum likelihood estimates of model parameters were obtained via a multilevel analysis with children as level-1, and school as level-2. Children who spent more time in sedentary activities and girls were less likely to comply with MVPA/daily. More mature children and those who use active transportation to school were more likely to attain the PA recommendation. Furthermore, greater accelerometer wear time and spring season increased the chance to achieve the recommended MVPA. In terms of school-level correlates, a greater number of available facilities was negatively associated with children MVPA compliance. Given the set of variables, our results showed that individual characteristics seem to be more relevant for children's compliance rates with PA/day than school context variables, which should be taken into account in the implementation of school policies and practices.

Obesity prevention in low socioeconomic status urban African-american adolescents: study design and preliminary findings of the HEALTH-KIDS Study.

OBJECTIVES: Obesity prevention among children and adolescents is a public health priority; however, limited school-based intervention trials targeting obesity have been conducted. This article provides an overview of the study design and baseline preliminary findings of our ongoing school-based intervention study. DESIGN: Randomized intervention trial to test a school-based, environmental obesity prevention program in urban low socioeconomic status (SES) African-American adolescents. The intervention program was developed based on several behavioral theories and was guided by preliminary findings based on focus group discussion and baseline data. SETTING: Four Chicago public schools in the US. SUBJECTS: Over 450 5-7th graders and their families and schools were involved. RESULTS: Our baseline data indicate a high prevalence of overweight (43% in boys and 41% in girls) and a number of problems in these children's physical activity and eating patterns. Only 26% reported spending > or = 20 min engaged in vigorous-moderate exercise in > or = 5 days over the past 7 days; 29% reported spending > or = 5 h each day watching TV, playing video games, or using computer. They also consumed too many fried foods and soft drinks. On average, 55% consumed fried foods > or = 2 times/day over the past 7 days; regarding soft drinks, 70% reported consuming > or = 2 times/day. CONCLUSION: School-based obesity prevention programs are urgently needed in the target US urban, low SES, minority communities. These data can be used to inform intervention activities.

Lack of preference for diazepam in anxious volunteers.

Using a choice procedure, these experiments tested whether diazepam is more highly preferred by anxious subjects than by normal control subjects. Subjects first sampled and then chose between two capsules containing diazepam (5 or 10 mg) and placebo, or amphetamine (5 mg) and placebo. The number of times each drug was chosen over placebo and the subjective effects of the drugs were measured. Anxious subjects did not differ from controls in their drug choices. Most subjects chose diazepam less often than placebo, especially at the higher dose, whereas they chose amphetamine more often than placebo. The subjective drug effects (including anxiety reduction after diazepam) were similar for anxious and nonanxious subjects, despite predrug differences in anxiety. The results suggest that individuals with high anxiety are not at greater risk for dependence on antianxiety drugs.

Psychotic exacerbations and enhanced vasopressin secretion in schizophrenic patients with hyponatremia and polydipsia.

BACKGROUND: For unclear reasons, life-threatening water intoxication often coincides with acute psychosis in polydipsic schizophrenic patients with chronic hyponatremia. In contrast, most polydipsic schizophrenic patients are normonatremic and never manifest hyponatremia. To explore whether the effect of acute psychosis on water balance differs in these 2 schizophrenic subgroups, we compared their responses to drug-induced psychotic exacerbations. METHODS: Matched polydipsic schizophrenic patients with (n = 6) and without (n = 8) hyponatremia were identified based on past and current indexes of fluid intake and hydration. A transient psychotic exacerbation was induced with an infusion of the psychotomimetic methylphenidate hydrochloride (0.5 mg/kg of body weight over a 60-second period). Antidiuretic hormone levels, subjective desire for water, and factors known to influence water balance were measured at 15-minute intervals for 2 hours. RESULTS: Except for the expected differences in plasma osmolality and sodium, basal measures were similar in the 2 groups. Following methylphenidate administration, antidiuretic hormone levels increased more in the hyponatremic patients (P < .02), despite their consistently lower plasma osmolality (P < .007). No known or putative antidiuretic hormone stimulus could account for this finding. Only basal positive psychotic symptoms (P < .09) and plasma sodium (P < .18) were even marginally associated with the peak antidiuretic hormone responses, but neither factor could explain the difference in the response by the 2 groups. CONCLUSION: Psychotic exacerbations are associated with enhanced antidiuretic hormone secretion, for unknown reasons, in schizophrenic patients with hyponatremia and polydipsia, thereby placing them at increased risk of life-threatening water intoxication.

Some conceptual and statistical issues in analysis of longitudinal psychiatric data. Application to the NIMH treatment of Depression Collaborative Research Program dataset.

Longitudinal studies have a prominent role in psychiatric research; however, statistical methods for analyzing these data are rarely commensurate with the effort involved in their acquisition. Frequently the majority of data are discarded and a simple end-point analysis is performed. In other cases, so called repeated-measures analysis of variance procedures are used with little regard to their restrictive and often unrealistic assumptions and the effect of missing data on the statistical properties of their estimates. We explored the unique features of longitudinal psychiatric data from both statistical and conceptual perspectives. We used a family of statistical models termed random regression models that provide a more realistic approach to analysis of longitudinal psychiatric data. Random regression models provide solutions to commonly observed problems of missing data, serial correlation, time-varying covariates, and irregular measurement occasions, and they accommodate systematic person-specific deviations from the average time trend. Properties of these models were compared with traditional approaches at a conceptual level. The approach was then illustrated in a new analysis of the National Institute of Mental Health Treatment of Depression Collaborative Research Program dataset, which investigated two forms of psychotherapy, pharmacotherapy with clinical management, and a placebo with clinical management control. Results indicated that both person-specific effects and serial correlation play major roles in the longitudinal psychiatric response process. Ignoring either of these effects produces misleading estimates of uncertainty that form the basis of statistical tests of hypotheses.

The influence of polydipsia on water excretion in hyponatremic, polydipsic, schizophrenic patients.

To determine whether polydipsia is responsible for the altered water excretion in the subset of polydipsic schizophrenic patients who develop hyponatremia, the regulation of antidiuretic function was assessed in polydipsic schizophrenic patients with hyponatremia (n = 5), polydipsic schizophrenic patients without hyponatremia (n = 5), nonpolydipsic schizophrenic patients (n = 6), and normal controls (n = 8). The severity and duration of polyuria were similar in the two polydipsic groups. After oral water loading, maximal free water clearance was similar across all four groups. Free water clearance diminished, however, at lower plasma osmolalities in the hyponatremic polydipsics (P < 0.02) and at higher plasma osmolalities in the normonatremic polydipsics (P < 0.05) relative to that in the nonpolydipsic schizophrenics and normal subjects. The increase in plasma vasopressin after osmotic stimulation with hypertonic saline was slightly, but significantly (P < 0.02), blunted in both polydipsic groups. Hyponatremia occurs in some polydipsic schizophrenics because the relationship between free water clearance to plasma osmolality/sodium is shifted to the left. Polydipsia per se is not responsible for this still unexplained shift.

A longitudinal study of plasma cortisol and depressive symptomatology by random regression analysis.

The authors utilized a random regression model to test the longitudinal relationship between depressive symptomatology and plasma cortisol levels obtained before and after the administration of dexamethasone in 62 affectively ill inpatients. This statistical model for longitudinal studies permits the inclusion of subjects with incomplete data as well as subjects measured at different time points. The most significant relationships were found between decreases in depressive symptoms and decreases in the 8:30 AM predexamethasone and the 4:00 PM postdexamethasone cortisol values. Patients were also classified as responders or nonresponders, and the rate of change in several plasma cortisol measures were separately analyzed for these two groups. No differences in the rate of change in plasma cortisol levels were found between responders and nonresponders. These results suggest that the decreases in cortisol production associated with clinical improvement may be partially explained by a regression toward the mean effect. Some of the possible explanations for these results are discussed.

The Altman Self-Rating Mania Scale.

We report on the development, reliability, and validity of the Altman Self-Rating Mania Scale (ASRM). The ASRM was completed during medication washout and after treatment by 22 schizophrenic, 13 schizoaffective, 36 depressed, and 34 manic patients. The Clinician-Administered Rating Scale for Mania (CARS-M) and Mania Rating Scale (MRS) were completed at the same time to measure concurrent validity. Test-retest reliability was assessed separately on 20 depressed and 10 manic patients who completed the ASRM twice during washout. Principal components analysis of ASRM items revealed three factors: mania, psychotic symptoms, and irritability. Baseline mania subscale scores were significantly higher for manic patients compared to all other diagnostic groups. Manic patients had significantly decreased posttreatment scores for all three subscales. ASRM mania subscale scores were significantly correlated with MRS total scores (r = .718) and CARS-M mania subscale scores (r = .766). Test-retest reliability for the ASRM was significant for all three subscales. Significant differences in severity levels were found for some symptoms between patient ratings on the ASRM and clinician ratings on the CARS-M. Mania subscale scores of greater than 5 on the ASRM resulted in values of 85.5% for sensitivity and 87.3% for specificity. Advantages of the ASRM over other self-rating mania scales are discussed.

A comparative evaluation of three self-rating scales for acute mania.

This study compared the performance of three self-rating mania scales, The Internal State Scale (ISS), the Self-Report Manic Inventory (SRMI), and the Altman Self-Rating Mania Scale (ASRM), in a group of patients with acute mania. Forty-four adult inpatients with bipolar disorder, manic or mixed, completed all scales shortly after admission, and 31 patients completed them again after 4-6 weeks of pharmacotherapy. Patients also were rated by clinicians on the Clinician-Administered Rating Scale for Mania (CARS-M). At baseline, scores on the ASRM and the ISS well-being subscale were significantly correlated with CARS-M scores. Posttreatment scores were significantly decreased for the ASRM, SRMI, and the ISS activation subscale. The sensitivities for each scale to correctly identify patients with acute symptoms was 45% for the ISS, 86% for the SRMI, and 93% for the ASRM. Specificities were 73%, 46.6%, and 33%, respectively. The ASRM and SRMI were more sensitive than the ISS in screening patients with acute mania. All three measures were sensitive to treatment effects; however, the item content of the SRMI and the poor sensitivity of the ISS may limit their utility in inpatient settings.

The Clinician-Administered Rating Scale for Mania (CARS-M): development, reliability, and validity.

There are currently seven rating scales available to assess manic symptomatology. All, however, have some limitations that could restrict their clinical and research utility. To resolve these deficiencies the Clinician-Administered Rating Scale for Mania (CARS-M) was developed and normed on 96 patients with mixed diagnoses during baseline and following treatment. Interrater reliability was established across multiple raters viewing 14 videotaped interviews and comparing agreement among individual items and total scores. Test-retest reliability was assessed on 36 patients twice during baseline. The mean intraclass correlation coefficient among five raters across items for each of the 14 patients was 0.81, and for total scores 0.93. Principal components analysis of items revealed two factors: mania, and psychosis. Test-retest reliability was significant for both factors (range = 0.78 to 0.95). Internal validity, comparing each item with its respective total factor score, revealed significant correlations for all items. Correlation of CARS-M total scores with mania rating scale (MRS) total scores was 0.94. Results indicate the CARS-M is both a reliable and valid measure of the severity of manic symptomatology, which incorporates a number of methodological improvements leading to greater precision and clinical utility.

Rearing experience and biogenic amine activity in infant rhesus monkeys.

In this report we present evidence that early social experience influences aspects of the function of brain biogenic amine systems, most notably the noradrenergic system. Biogenic amine activity was studied in mother- vs. peer-reared monkey infants over the first 6 months of life and in response to two housing transitions. Norepinephrine (NE), 3-methoxy-4-hydroxyphenylglycol (MHPG), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) levels in cerebrospinal fluid (CSF) were measured. Peer-reared monkeys showed significantly higher CSF levels of norepinephrine and MHPG than mother-reared animals over early development, but showed an attentuated NE response to separation and group formation compared to mother-reared animals. Peer-reared monkeys showed a greater developmental decline in 5-HIAA levels than mother-reared monkeys. There were no rearing effects for DOPAC or HVA over early development; however, peer-reared monkeys showed significantly lower HVA and DOPAC concentrations at 6-8 months of age. The results add to evidence for the influence of primate mothers on the psychobiological development of central nervous system neurotransmitter systems in their infants, and suggest that the noradrenergic system is among the more sensitive of these to early experience.

Differences between anhedonic and normally hedonic depressive states.

In this study of 101 patients who met DSM-III criteria for major depression, those with extreme anhedonia (N = 23) were younger, more depressed, and less neurotic than the patients with a normal-range capacity for pleasurable experiences (N = 78). The anhedonic depressed patients recovered more rapidly; at discharge they consequently had levels of symptom severity equal to those of the hedonic patients, yet they remained significantly more anhedonic. The anhedonic patients exhibited loss of pleasure in appetite, sex, social contacts, and work, which suggests a global dulling of the capacity for pleasure.

Association of nonsuppression of cortisol on the DST with primary polydipsia in chronic schizophrenia.

Thirteen polydipsic and 40 nonpolydipsic chronic schizophrenic patients received the dexamethasone suppression test while stabilized on psychotropic medication regimens. Thirty-eight percent (N = 5) of those with polydipsia but only 5% (N = 2) of those without polydipsia were nonsuppressors of cortisol (i.e., had an abnormal response). It is suggested that hippocampal dysfunction could cause both polydipsia and cortisol dysregulation in these patients.

Clinical predictors of suicide in patients with major affective disorders: a controlled prospective study.

The authors report prospective uniform clinical data differentiating 25 patients who committed suicide from 929 patients who did not in a group of 954 patients with major affective disorder followed for an average of 4 years in the Collaborative Program on the Psychobiology of Depression. Eight (32%) of the suicides occurred within 6 months and 13 (52%) within 1 year of entry into the study. Hopelessness, loss of pleasure or interest, and mood cycling during the index episode differentiated the suicide group. Diagnostic subcategories, suicidal ideation at entry to the study, suicide attempts during current or past episodes, and medical severity of prior attempts did not differentiate the suicide group.

Failure of urinary MHPG levels to predict treatment response in patients with unipolar depression.

The authors studied 64 depressed patients who were receiving a vanillylmandelic acid (VMA)-free diet and underwent a washout period (mean, 24 days) before treatment. During the washout period, a mean of 2.5 multiple 24-hour urinary 3-methoxy-4-hydroxyphenylglycol (MHPG) samples per patient were collected. Thirty-four patients were then treated with a "noradrenergic" antidepressant only (e.g., imipramine), and seven were treated with a "serotonergic" antidepressant only (e.g., amitriptyline). Twelve patients received combined drug treatment and 11 others spontaneously remitted. Response to treatment was rated on a clinical global evaluation scale from 1 (little or no response) to 7 (maximum response). No relationship was found between response to treatment, type of treatment, and the average pretreatment 24-hour urinary MHPG level. The authors thus failed to confirm the hypothesis that a low MHPG level predicts response to antidepressant treatment.

Length of stay and recidivism in schizophrenia: a study of public psychiatric hospital patients.

OBJECTIVE: Psychiatric beds in public hospitals have decreased 80% since 1955, but admissions have risen correspondingly, largely because of high recidivism rates. Decreases in numbers of beds have been partly achieved by shortening the length of stay, which lessened by half between 1970 and 1980. This study was undertaken to determine whether duration of hospital treatment affects the rate and rapidity of relapse among schizophrenic patients. METHOD: Data on 1,500 patients from 10 state hospitals were gathered for 18 months after initial discharge. Predictor variables included age, sex, marital status, race, number of previous admissions, location of the facility, and length of stay. Data were analyzed by survival analysis with a Cox regression model for two times to initial relapse: 30 days and 18 months (outcome). RESULTS: Length of stay was significantly related to each time to relapse after the effects of number of previous admissions and age were partialed out. Facility location was not predictive, but intrahospital effects were tested by examining the data on the largest facility; again, length of stay significantly predicted relapse. CONCLUSIONS: Although the magnitude of the effect was small, the clinical significance of the findings is the greater likelihood that brief-stay patients will be rehospitalized within 30 days after discharge than will patients treated for longer periods. Brief hospitalization seems generally applicable to psychiatric populations, but there may be a small but important group of seriously mentally ill patients for whom other alternatives are possibly more appropriate and should be explored.

Time-related predictors of suicide in major affective disorder.

The authors studied 954 psychiatric patients with major affective disorders and found that nine clinical features were associated with suicide. Six of these--panic attacks, severe psychic anxiety, diminished concentration, global insomnia, moderate alcohol abuse, and severe loss of interest or pleasure (anhedonia)--were associated with suicide within 1 year, and three others--severe hopelessness, suicidal ideation, and history of previous suicide attempts--were associated with suicide occurring after 1 year. These findings draw attention to the importance of 1) standardized prospective data for studies of suicide, 2) assessment of short-term suicide risk factors, and 3) anxiety symptoms as modifiable suicide risk factors within a clinically relevant period.

Regression toward the mean: more on the price of beer and the salaries of priests.

Investigators must take great care in studying the temporal association between biological and clinical data. By selecting patients on the basis of deviant levels of a biological parameter, it often is impossible to separate the effect of regression toward the mean from a temporal association of clinical interest. Experimental strategies that focus exclusively on subjects with extreme values are particularly prone to misinterpreting the effects of regression toward the mean as a temporal change in the variable of interest. We cite specific examples of two previous studies of the relationship between the dexamethasone suppression test (DST) and clinical response in depression. Contrary to the conclusions of the investigators, normalization of the DST had no relation to clinical response in the first 5 weeks of treatment. The decrease of post-dexamethasone cortisol levels occurred regardless of clinical response, most likely due to the effect of regression toward the mean.

Response of psychotic and nonpsychotic depressed patients to tricyclic antidepressants.

The response to tricyclic antidepressants (TCAs) is studied in 75 of 121 depressed patients classified as psychotic or nonpsychotic subtypes by Research Diagnostic Criteria. Response was assessed by a clinical global evaluation scale. Of the 75 patients treated with TCAs, 40 (68%) of the nonpsychotic subtype responded in contrast to only 4 (25%) of the psychotic subtype. Adjusting for the effects of chronicity, sex, age, incapacity, agitation, retardation, endogenicity, and the unipolar-bipolar distinction as covariates, it was found that these variables failed to alter the differential response rate of the psychotic and nonpsychotic depressed groups. A literature review of 1054 patients revealed that 67% of the nonpsychotic depressed patients responded to TCAs compared with only 35% of the psychotic depressed patients.