Weight-related attitudes and behaviors of adolescent boys and girls who are encouraged to diet by their mothers

OBJECTIVE

To assess the relationships between mothers' reports of dieting and encouraging adolescents to diet and adolescents' reports of their own dieting practices and weight-related concerns.

DESIGN

Cross-sectional study of parent interviews and adolescent surveys in an ethnically-diverse sample.

SUBJECTS

A total of 810 adolescents (n=381 boys and n=429 girls) and their mothers.

RESULTS

Mothers' dieting was associated with their adolescent girls' weight-related concerns and behaviors, but these associations were not significant after adjusting for girls' body mass index (BMI). In contrast, mothers' encouragement for sons to diet was associated with sons' binge eating, dieting and other weight-control behaviors, even after controlling for sons' BMI. Compared with mothers who did not encourage their child to diet, mothers who encouraged their child to diet were significantly heavier women and were more likely to view their child as overweight. Forty-three percent of boys and 46% of girls who were encouraged by their mothers to diet were classified as nonoverweight by federal guidelines.

CONCLUSIONS

Boys who are encouraged by their mothers to diet may be at risk for health-compromising eating and dieting behaviors, particularly binge-eating, fasting, eating a little bit of food and skipping meals. Parents who are concerned about their children's weight should be educated to encourage healthy eating habits and physical activity to promote their children's health, including healthy weight control.

Prevalence and correlates of large weight gains and losses

OBJECTIVE

To examine the prevalence and correlates of large weight gains and losses over a 3 y period in a heterogeneous population of participants in a study of weight gain prevention.

DESIGN AND MEASURES

Analyses based on a cohort of 823 participants in a weight gain prevention study whose weight was measured on at least two of four annual examinations.

RESULTS

Weight gains and losses of >or=5% body weight over 1 y were observed in 9.3 and 15% of the population, respectively. Weight gains among those initially losing weight were significantly greater (3.9 kg) than among those experiencing stable weight (0.8 kg) or a large weight gain (1.5 kg) over the following 2 y. Cumulative weight changes over 3 y were -2.6, 1.0 and 7.6 kg among large loss, weight stable and large gain groups, respectively. Large weight loss was more common in smokers, large gains were more common in younger people and in those with a more extensive weight loss history, and stable weight was observed more often in individuals with less extensive histories of weight loss.

CONCLUSION

The high prevalence of large short-term weight gains and losses in this heterogeneous population, their apparent resistance to short-term reversal, and the strength of their relationship to longer-term weight trends suggest that rapid weight change over relatively short time intervals is a phenomenon that deserves more research attention. Short periods of rapid weight gain may contribute importantly to rapidly rising obesity rates.

Understanding weight stigmatization: a focus group study

OBJECTIVES

The purpose of this research was to investigate, in a nonclinical sample of adults, thoughts on and experiences with weight stigmatization.

DESIGN

Focus groups were used to collect information. Participants were recruited through a newspaper advertisement and flyers posted in public places in Minneapolis and St. Paul. During the focus groups, participants were led in a discussion about their thoughts on weight stigmatization and personal experiences of being treated differently or poorly because of their weight.

SUBJECTS

Six gender-specific focus groups consisted of 31 adult volunteers (17 women and 14 men).

VARIABLES MEASURED

Perceptions of weight-based stereotypes and weight stigmatization and personal reports of having been treated differently or poorly owing to weight were measured.

RESULTS

Participants reported a variety of experiences of being treated differently or poorly because of their weight. These included teasing, harassment, slurs and insults, negative judgments and assumptions, and perceived discrimination. Participants reported that such experiences occurred at home, among friends and strangers, at work, and in health care settings. Women reported a greater number and a greater variety of negative experiences than men.

IMPLICATIONS

The results indicated that participants experienced weight-based stigmatization in many aspects of their lives. Awareness of these experiences may assist in the development of treatments for overweight individuals.

Interventions for weight loss and weight gain prevention among youth: current issues

The recent increase in the prevalence of paediatric obesity is one of the most pressing public health concerns today because of the immediate and long term health consequences associated with this often intractable disease. Efforts are currently being made to reduce the prevalence of paediatric obesity. Youth weight loss studies have produced significant long term results. Most of these programmes included behaviour modification, diet and exercise. Studies have suggested that lifestyle exercise programmes may produce the best long term results. Effective components of these programmes appear to be parental involvement, reduced intake of foods having high energy density and reductions in physical inactivity. Future weight loss studies need to determine the type, intensity, and duration of exercise that will produce acceptable adherence and consequent long term weight loss, and to ascertain the reinforcing factors that determine youth behaviour choice. Weight gain prevention interventions for youth are clearly in their infancy. This review describes 3 completed and 2 ongoing weight gain prevention trials. One study showed reductions in the prevalence of obesity among junior high school girls, but not among boys. Another study among elementary school students showed significant mean decreases in body mass index in boys and girls following an intervention specifically to reduce time spent viewing television. Whether these studies altered food intake or increased physical activity remains unclear. A combination of weight loss treatment and weight gain prevention strategies employed in parallel is likely to yield the greatest benefits. Development and testing of novel intervention strategies, using innovative behavioural approaches to increase the likelihood that children will adopt healthy dietary, physical activity, and sedentary behaviour patterns, holds great promise to significantly reduce the epidemic of obesity.

The relationship between restraint and weight and weight-related behaviors among individuals in a community weight gain prevention trial

PURPOSE

The present study evaluated the cross-section and prospective associations between the Eating Inventory's (EI) total, flexible and rigid dietary restraint scales and changes in weight and behaviors in a community sample of adults enrolled in a 3 y weight gain prevention study.

METHODS

Subjects were participants in the Pound of Prevention (POP) study, a community-based weight gain prevention trial.

RESULTS

Higher levels of baseline total, flexible and rigid dietary restraint were related to lower weight and more weight-controlling behaviors at the baseline assessment. Baseline restraint measures positively predicted increases in weighing frequency over the 3 y follow-up. Increases in restraint over the follow-up period were related to decreases in weight, energy intake and television watching, and increases in self-weighing and physical activity.

CONCLUSION

The EI's total, flexible and rigid restraint scales were not differently associated with weight and behaviors in this heterogeneous sample of adults who were attempting to lose weight. Developing methods to increase behavioral and cognitive strategies to control weight may help to prevent weight gain in clinical and community samples.

Social impulsivity inversely associated with CSF 5-HIAA and fluoxetine exposure in vervet monkeys

Animal and human research suggests that the central serotonin system is involved in the inhibition of impulsive behavior. Two studies were designed to assess this relationship in male vervet monkeys (Cercopithecus aethiops sabaeus) using a standardized test of impulsivity in a social context: the Intruder Challenge. In the first study, an index of impulsivity in response to an unfamiliar adult male intruder (including latency to approach and aggressive and assertive interactions) was inversely correlated with levels of the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA) in cisternal cerebrospinal fluid (r = -0.33, p <.01, n = 138). The approach, but not aggressive, component of the Impulsivity Index was the primary contributor to this relationship (partial r = -0.27, p <.01). The second experiment compared responses to the Intruder Challenge after 9 weeks of daily treatment with fluoxetine (2 mg/kg, i.m.) or vehicle. Fluoxetine-treated subjects (n = 6) had significantly lower Impulsivity Index scores than controls (n = 12). The results from these two investigations provide evidence for serotonergic influences on social impulsivity.

Does weight loss maintenance become easier over time?

OBJECTIVE

Studies of health-related behaviors, including weight loss, have shown that risk of relapse decreases over time, although reasons for this relationship are unclear. The purpose of this cross-sectional study was to determine if subjects who have maintained weight losses for varying periods of time report different strategies for weight loss maintenance or differences in the effort and pleasure associated with weight maintenance behaviors.

RESEARCH METHODS AND PROCEDURES

Subjects were 758 women and 173 men who had maintained losses of at least 30 lb (mean = 60 lb) for 2 years or longer (mean = 6.8 +/- 7.0 years). Self-administered questionnaires assessed subjects' use of weight maintenance strategies in the past year and their perceptions of the effort, attention, and pleasure associated with weight maintenance.

RESULTS

Subjects who had maintained weight losses longer used fewer weight maintenance strategies and reported that less effort was required to diet and maintain weight and that less attention was required to maintain weight. The pleasure derived from exercise, low-fat eating, and maintaining weight was unrelated to duration of weight loss maintenance.

DISCUSSION

As duration increases, a shift in the balance between the effort and pleasure of weight maintenance may occur. This shift may increase the likelihood of continued maintenance.

A case-control study of successful maintenance of a substantial weight loss: individuals who lost weight through surgery versus those who lost weight through non-surgical means

OBJECTIVE

To determine if method of weight loss (surgery; non-surgery) is associated with current levels of psychosocial functioning or current weight maintenance behaviors in individuals who have lost large amounts of weight.

DESIGN

Subjects were 67 cases and 67 controls selected from the National Weight Control Registry, a longitudinal study of individuals successful at long-term maintenance of weight loss. Cases had initially lost weight through bariatric surgery while controls had lost weight through non-surgical means. The current psychosocial functioning and weight maintenance behaviors of cases and controls were assessed and compared.

RESULTS

Cases and controls were matched on gender, current weight and total weight loss. Surgical cases reported significantly higher fat intake and lower physical activity levels. There were no differences in cases' and controls' reports of the impact of weight loss on other areas of their lives, neither were there differences on measures of depression or binge-eating.

CONCLUSIONS

Reported improvement in psychosocial functioning did not depend upon how weight was initially lost, but cases and controls appear to be using very different behaviors to maintain their weight losses.

The prevalence of weight loss maintenance among American adults

BACKGROUND

Previous studies suggest that few individuals achieve long-term weight loss maintenance. Because most of these studies were based on clinical samples and focused on only one episode of weight loss, these results may not reflect the actual prevalence of weight loss maintenance in the general population.

DESIGN

A random digit dial telephone survey was conducted to determine the point prevalence of weight loss maintenance in a nationally representative sample of adults in the United States. Weight loss maintainers were defined as individuals who, at the time of the survey, had maintained a weight loss of > or =10% from their maximum weight for at least 1 y. The prevalence of weight loss maintenance was first determined for the total group (n = 500), and then for the subgroup of individuals who were overweight (body mass index BMI > or =27 kg/m2 at their maximum (n = 228).

RESULTS

Weight loss was quite common in this sample: 54% of the total sample and 62% of those who were ever overweight reported that they had lost > or =10% of their maximum weight at least once in their lifetime, with approximately one-half to two-thirds of these cases being intentional weight loss. Among those who had achieved an intentional weight loss of > or =10%, 47-49% had maintained this weight loss for at least 1 y at the time of the survey; 25-27% had maintained it for 5 y or more. Fourteen percent of all subjects surveyed and 21% of those with a history of obesity were currently 10% below their highest weight, had reduced intentionally, and had maintained this 10% weight loss for at least 1 y.

CONCLUSIONS

A large proportion of the American population has lost > or =10% of their maximum weight and has maintained this weight loss for at least 1 y. These findings are in sharp contrast to the belief that few people succeed in long-term weight loss maintenance.

The behavioral characteristics of individuals who lose weight unintentionally

OBJECTIVE

To determine whether individuals who unintentionally lost weight differ from individuals who intentionally lost weight in behavioral characteristics related to chronic disease risk factors.

DESIGN

A random-digit dial telephone survey was conducted among a representative sample of American adults (n = 500).

SUBJECTS

Of the 500 individuals sampled, 139 were currently > or = 10% below their lifetime maximum weight. These individuals were asked whether their weight loss was unintentional or intentional. Unintentional (n =49) and intentional (n = 89) weight losers were compared on measures of dietary intake, physical activity, smoking, drinking, and self-reported health status.

RESULTS

Unintentional weight losers had higher levels of smoking and drinking, were less physically active, and were less concerned about their diet and fat intake. Unintentional weight losers did not report having higher levels of disease such as high blood pressure or diabetes. However, unintentional weight losers who reported having such diseases were more likely to report that their weight loss had no effect or had worsened their disorder.

DISCUSSION

Compared to intentional weight losers, those who lost their weight unintentionally reported engaging in more negative health behaviors that are related to disease morbidity and mortality. These data suggest that unintentional weight loss may be part of a cluster of behaviors that have a negative health impact.

Behavioral strategies of individuals who have maintained long-term weight losses

OBJECTIVE

The purpose of the present study was to compare the behaviors of individuals who have achieved long-term weight loss maintenance with those of regainers and weight-stable controls.

RESEARCH METHODS AND PROCEDURES

Subjects for the present study were participants in a random-digit dial telephone survey that used a representative sample of the U.S. adult population. Eating, exercise, self-weighing, and dietary restraint characteristics were compared among weight-loss maintainers: individuals who had intentionally lost > or =10% of their weight and maintained it for > or = 1 year (n = 69), weight-loss regainers: individuals who intentionally lost > or = 10% of their weight but had not maintained it (n = 56), and weight-stable controls: individuals who had never lost > or = 10% of their maximum weight and had maintained their current weight (+/-10 pounds) within the past 5 years (n = 113).

RESULTS

Weight-loss maintainers had lost an average of 37 pounds and maintained it for over 7 years. These individuals reported that they currently used more behavioral strategies to control dietary fat intake, have higher levels of physical activity (especially strenuous activity), and greater frequency of self-weighing than either the weight-loss regainers or weight-stable controls. Maintainers and regainers did not differ in reported levels of dietary restraint, but both had higher levels of restraint than the weight-stable controls.

DISCUSSION

These results suggest that weight-loss maintainers use more behavioral strategies to control their weight than either regainers or weight-stable controls. It would thus appear that long-term weight maintenance requires ongoing adherence to a low-fat diet and an exercise regimen in addition to continued attention to body weight.

Resting energy expenditure in reduced-obese subjects in the National Weight Control Registry

BACKGROUND

Weight loss in obese subjects is associated with a reduction in resting metabolic rate (RMR). Whether the reduction can be explained solely by a reduction in lean body mass remains controversial.

OBJECTIVE

Our objective was to determine whether the reduction in RMR after weight loss was proportional to the decrease in lean mass alone or was greater than could be explained by body composition.

DESIGN

We measured the RMR, fasting respiratory quotient (RQ), and body composition in 40 reduced-obese subjects [ie, 7 men and 33 women who had lost > or = 13.6 kg (30 lb) and maintained the loss for > or = 1 y] enrolled in the National Weight Control Registry and 46 weight-matched control subjects (9 men, 37 women).

RESULTS

A stepwise multiple regression found lean mass, fat mass, age, and sex to be the best predictors of RMR in both groups. After adjusting RMR for these variables, we found no significant difference in RMR (5926 +/- 106 and 6015 +/- 104 kJ/d) between the 2 groups (P = 0.35). When we adjusted fasting RQ for percentage body fat and age, the reduced-obese group had a slightly higher (0.807 +/- 0.006) RQ than the control group (0.791 +/- 0.005, P = 0.05). This may have been due to the consumption of a diet lower in fat or to a reduced capacity for fat oxidation in the reduced-obese group.

CONCLUSION

These results show that in at least some reduced-obese individuals there does not seem to be a permanent obligatory reduction in RMR beyond the expected reduction for a reduced lean mass.

What predicts weight regain in a group of successful weight losers?

This study identified predictors of weight gain versus continued maintenance among individuals already successful at long-term weight loss. Weight, behavior, and psychological information was collected on entry into the study and 1 year later. Thirty-five percent gained weight over the year of follow-up, and 59% maintained their weight losses. Risk factors for weight regain included more recent weight losses (less than 2 years vs. 2 years or more), larger weight losses (greater than 30% of maximum weight vs. less than 30%), and higher levels of depression, dietary disinhibition, and binge eating levels at entry into the registry. Over the year of follow-up, gainers reported greater decreases in energy expenditure and greater increases in percentage of calories from fat. Gainers also reported greater decreases in restraint and increases in hunger, dietary disinhibition, and binge eating. This study suggests that several years of successful weight maintenance increase the probability of future weight maintenance and that weight regain is due at least in part to failure to maintain behavior changes.

What predicts weight regain in a group of successful weight losers?

This study identified predictors of weight gain versus continued maintenance among individuals already successful at long-term weight loss. Weight, behavior, and psychological information was collected on entry into the study and 1 year later. Thirty-five percent gained weight over the year of follow-up, and 59% maintained their weight losses. Risk factors for weight regain included more recent weight losses (less than 2 years vs. 2 years or more), larger weight losses (greater than 30% of maximum weight vs. less than 30%), and higher levels of depression, dietary disinhibition, and binge eating levels at entry into the registry. Over the year of follow-up, gainers reported greater decreases in energy expenditure and greater increases in percentage of calories from fat. Gainers also reported greater decreases in restraint and increases in hunger, dietary disinhibition, and binge eating. This study suggests that several years of successful weight maintenance increase the probability of future weight maintenance and that weight regain is due at least in part to failure to maintain behavior changes.

Prevalence differences in depression among males and females: are there evolutionary explanations?

Differences in male-female prevalence rates of depression are interpreted in evolutionary perspective. Three evolutionary hypotheses are evaluated: (a) depression represents an evolved strategy to deal with adverse social interactions, particularly among partners, (b) depression has self-preservative and manipulative features, and (c) depression is a consequence of failing to achieve biological goals. While these hypotheses are not necessarily mutually exclusive, evolutionary explanations often suffer from not specifying which hypothesis is primary and which are secondary. We argue that failing to achieve biological goals is primary and that evolved strategies and self-preservative and manipulative behaviour are secondary. Findings pointing to depression-contributing features of male-female differences, asymmetries in male-female relationships and male-female differences associated with reproduction are discussed to support our view that evolutionary explanations can adequately account for a significant percentage of the reported prevalence differences.

Psychological symptoms in individuals successful at long-term maintenance of weight loss

Set point theory suggests that successful maintenance of weight loss ("weight suppression") may be associated with psychological distress. This study examined the association between psychological symptoms and body weight suppression by using a registry of 629 women and 155 men who lost at least 13.6 kg (mean loss = 30 +/- 15 kg) and maintained the loss for at least 1 year (mean duration = 5.5 +/- 6.8 years). Participants completed measures of mood, distress, restraint, disinhibition, bingeing, and purging. Maintainers' levels of distress and depression were lower than those of psychiatric samples and resembled those of community-based samples. Binge-eating and purging rates were comparable to rates of community samples. Maintainers' levels of restraint and disinhibition were markedly different from those of eating-disordered samples, resembling levels found in patients recently treated for obesity. There was no evidence that long-term suppression of body weight is associated with psychological distress.

Long-term maintenance of weight loss: do people who lose weight through various weight loss methods use different behaviors to maintain their weight?

OBJECTIVE

To evaluate whether individuals who lost weight on their own (n = 447), through organized programs (n = 313) or with liquid formula (n = 133) would differ in the strategies they used to maintain their weight losses.

DESIGN

All subjects were members of the National Weight Control Registry, had lost > or = 13.6 kg (30 pounds), and kept it off at least one year (mean weight loss = 30.1+/-14.9 kg and mean duration of maintenance = 5.7+/-6.9 y).

RESULTS

Liquid Formula users differed from the other two groups on many characteristics; they were more likely to be women, older, heavier, and to have had a medical disorder prior to weight loss. To maintain their weight loss, the Liquid Formula group reported greater use of dietary strategies (for example, counting calories, limiting the amount of calories from fat) and higher dietary restraint. Liquid Formula users reported that weight maintenance was more difficult than losing weight, whereas individuals who lost weight on their own reported the reverse. The On Own group reported expending a higher percentage of calories through strenuous activities such as running and weight lifting, and reported weighing themselves more frequently to maintain weight loss. Despite these behavioral differences, all three groups are maintaining their weight losses similarly by eating a low calorie diet (5792.3 kJ/d and 25% of daily calories from fat) and engaging in high levels of physical activity (11847.3 kJ/week).

CONCLUSIONS

Despite using different methods to lose weight, individuals who lost weight on their own, through an organized program, or with a liquid formula, use similar behavioral strategies to maintain their weight loss.

Persons successful at long-term weight loss and maintenance continue to consume a low-energy, low-fat diet

OBJECTIVES

To describe the dietary intakes of persons who successfully maintained weight loss and to determine if differences exist between those who lost weight on their own vs those who received assistance with weight loss (eg, participated in a commercial or self-help program or were seen individually by a dietitian). Intakes of selected nutrients were also compared with data from the third National Health and Nutrition Examination Survey (NHANES III) and the 1989 Recommended Dietary Allowances (RDAs).

SUBJECTS

Subjects were 355 women and 83 men, aged 18 years or older, primarily white, who had maintained a weight loss of at least 13.6 kg for at least 1 year, and were the initial enrollees in the ongoing National Weight Control Registry. On average, the participants had lost 30 kg and maintained the weight loss for 5.1 years.

METHODS

A cross-sectional study in which subjects in the registry completed demographic and weight history questionnaires as well as the Health Habits and History Questionnaire developed by Block et al. Subjects' dietary intake data were compared with that of similarly aged men and women in the NHANES III cohort and to the RDAs. Adequacy of the diet was assessed by comparing the intake of selected nutrients (iron; calcium; and vitamins C, A, and E) in subjects who lost weight on their own or with assistance.

RESULTS

Successful maintainers of weight loss reported continued consumption of a low-energy and low-fat diet. Women in the registry reported eating an average of 1,306 kcal/day (24.3% of energy from fat); men reported consuming 1,685 kcal (23.5% of energy from fat). Subjects in the registry reported consuming less energy and a lower percentage of energy from fat than NHANES III subjects did. Subjects who lost weight on their own did not differ from those who lost weight with assistance in regards to energy intake, percent of energy from fat, or intake of selected nutrients (iron; calcium; and vitamins C, A, and E). In addition, subjects who lost weight on their own and those who lost weight with assistance met the RDAs for calcium and vitamins C, A, and E for persons aged 25 years or older.

APPLICATIONS

Because continued consumption of a low-fat, low-energy diet may be necessary for long-term weight control, persons who have successfully lost weight should be encouraged to maintain such a diet.

A descriptive study of individuals successful at long-term maintenance of substantial weight loss

The National Weight Control Registry (NWCR) is, to the best of our knowledge, the largest study of individuals successful at long-term maintenance of weight loss. Despite extensive histories of overweight, the 629 women and 155 men in the registry lost an average of 30 kg and maintained a required minimum weight loss of 13.6 kg for 5 y. A little over one-half of the sample lost weight through formal programs; the remainder lost weight on their own. Both groups reported having used both diet and exercise to lose weight and nearly 77% of the sample reported that a triggering event had preceded their successful weight loss. Mean (+/-SD) current consumption reported by registry members was 5778 +/- 2200 kJ/d, with 24 +/- 9% of energy from fat, Members also appear to be highly active: they reported expending approximately 11830 kJ/wk through physical activity. Surprisingly, 42% of the sample reported that maintaining their weight loss was less difficult than losing weight. Nearly all registry members indicated that weight loss led to improvements in their level of energy, physical mobility, general mood, self-confidence, and physical health. In summary, the NWCR identified a large sample of individuals who were highly successful at maintaining weight loss. Future prospective studies will determine variables that predict continued maintenance of weight loss.

Databases for clinical psychiatry

Clinical information systems support patient care and research while providing data for administrative use. We assessed the informational needs of the psychiatrists at UCLA Neuropsychiatric Hospital and used the resulting criteria in evaluating commercial computer products. The systems that appear to be least expensive, most powerful, and most suitable for widespread use are assembled from various off-the-shelf packages. These newer systems use a structured query language (SQL) database with a graphic user interface. An SQL database can support both large and small clinical operations, and a graphic interface is easy to use. Commercial software systems are too expensive for a small psychiatric hospital or department, but a customized SQL database can be purchased and installed at lower cost.

Taxane-specific monoclonal antibodies: measurement of taxol, baccatin III, and "total taxanes" in Taxus brevifolia extracts by enzyme immunoassay

Three monoclonal antibodies with either specificity to taxol or baccatin III, or cross-reactivity with several common taxanes have been prepared and used to develop sensitive competitive-inhibition enzyme immunoassays. The hybridomas producing these monoclonal antibodies were obtained by fusing P3X63Ag8.653 plasmacytoma cells and splenocytes from mice hyperimmunized with keyhole limpet hemocyanin-7-succinyltaxol or -7-succinylbaccatin III conjugates. Direct and indirect competitive inhibition enzyme immunoassays were developed with these monoclonal antibodies and microtiter plates coated with bovine serum albumin conjugates of the complementary hapten. Detection limits for the direct competitive inhibition enzyme immunoassays, conducted in buffer containing 10% MeOH, were 0.6 nM taxol for 3C6 (anti-taxol); 1.1 nM baccatin III for 3H5 (anti-baccatin III); and 0.6 nM taxol or baccatin III for 8A10 (anti-taxane). The immunoassays accurately detected taxol, baccatin III, and "total taxanes" in crude MeOH extracts of Taxus brevifolia bark and in hplc fractions of these extracts.

Menstrual cycle and social behavior in vervet monkeys

We assessed the relationship between social behavior and the menstrual cycle in 11 adult female vervet monkeys (Cercopithecus aethiops sabaeus) living in an established, stable social group. The findings indicated that fluctuations in ovarian steroids are accompanied by behavioral changes in vervet monkeys. A significant increase in aggressive action, avoidance of social overtures, and retreats from threat occurred during the late luteal phase. However, the social environment can greatly affect behavior independent of the phase of the menstrual cycle. The 10 nondominant (or subordinate) individuals not only exhibited behavioral changes across their own menstrual cycles, but also were responsive to the dominant female's cycle. During the dominant female's late luteal phase, subordinate females significantly increased aggression and decreased social activity. Some of behavioral patterns in female vervet monkeys are therefore relatively independent of direct hormonal modulation and support the contention of the dominant female as the driving force for behavioral changes related to aggression and social interaction. The differential effect of hormones and social status and other environmental factors on behavior has not been critically evaluated in human studies of the premenstrual syndrome. The present study suggests that it is important to assess which behavioral patterns in women are hormonally mediated and which are dependent on the environment.

High-performance liquid chromatography and micellar electrokinetic chromatography of taxol and related taxanes from bark and needle extracts of Taxus species

High-performance liquid chromatography (HPLC) and micellar electrokinetic chromatography (MEKC) were applied for the separation of taxol, cephalomannine, and baccatin III in crude extracts from the needle and bark of Taxus species. The chromatogram of the bark extract was cleaner than that of the needle allowing a more reliable detection of taxol and cephalomannine in the bark extract. However, HPLC quantitation of taxol in the needle extract would be difficult due to coeluting taxinines. Nevertheless, this was not a problem in the MEKC experiment. In comparison to HPLC, MEKC offered baseline resolution of taxol from taxinines in the needle extract, less solvent waste, a smaller sample requirement, and the simultaneous detection of taxol, cephalomannine and baccatin III in a relatively simpler electrophoretic run.

Determination of taxanes in Taxus brevifolia extracts by tandem mass spectrometry and high-performance liquid chromatography

A tandem mass spectrometric (ms/ms) method using desorption chemical ionization is described for the quantitation of taxol [1], cephalomannine [2], and baccatin III [3] found in Taxus brevifolia bark and needle extracts. A parent ion scan was used to simultaneously determine the weight percentages of 1-3 in bark and needle samples by the method of standard addition. In an alternative experiment, the concentration of 1 in the same samples was determined by ms/ms using trideuterated 10-acetyltaxol [7a] as an internal standard. High-performance liquid chromatography (hplc) was also used to determine the weight percentages of 1-3 in the same T. brevifolia bark and needle extracts with an external standard. The ms/ms method of quantitation by internal standard is the best overall method of analysis examined. With this method, 1 was quantitated in the T. brevifolia extracts at the low picomole level with a relative standard deviation of 17% or better for all samples analyzed with an analysis time of less than five min per sample. The precision, level of quantitation, and speed of analysis of the three methods of taxane quantitation are compared.

Individual differences in basal cisternal cerebrospinal fluid 5-HIAA and HVA in monkeys. The effects of gender, age, physical characteristics, and matrilineal influences

We examined the effects of gender, age, weight, length, body shape (ectomorphy), and matrilineal influences on cisternal cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5-HIAA) and homovanillic acid (HVA) in 78 socially living adult and adolescent vervet monkeys. CSF 5-HIAA and the 5-HIAA:HVA ratio were higher (by 27% and 18%, respectively) in females. In both sexes, CSF 5-HIAA and the 5-HIAA:HVA ratio increased with age. Neither weight nor length were independently related to CSF 5-HIAA or HVA; however, shape correlated with CSF 5-HIAA and HVA in males (higher in thin, long subjects). Male offspring had CSF 5-HIAA concentrations and 5-HIAA:HVA ratios that were significantly closer to their mothers than did age-matched, maternally unrelated males. Repeated measures of CSF 5-HIAA and HVA in another 22 males living in unvarying settings showed that individual differences in these measures persisted over time. The data underscore the impact of gender, age, and matrilineal relationships on individual differences in CSF monoamine metabolites and highlight the importance of controlling for age and gender in neuropharmacological investigations of clinical populations.

Age, alcoholism and depression are associated with low levels of urinary melatonin

Two normal control populations, separated by 8,000 miles and 24 degrees of latitude, had similar six-month mean values for overnight urinary melatonin concentrations. These values were significantly higher than six-month values for depressed subjects and abstinent alcoholic subjects, while the means for the two clinical populations were similar. Age and urinary melatonin concentration in the control and clinical populations were inversely related, but the slopes of the linear regression equations were ten times steeper for the control populations than for the clinical populations. Differences in age and sex distributions accounted for some of the differences in values between controls and the clinical populations, although controls still differed from the clinical populations, even after sex and age were factored out. The disparate slopes for age and melatonin concentrations may contribute to some of the conflicting findings of studies comparing populations of different ages. The total melatonin content in the samples from alcoholic subjects, but not the depressed subjects, was lower than that for controls. The difference in the urinary melatonin concentration between the controls and the two patient groups was not accounted for by difference in duration of urine collection period, hours of sleep or body weight.

Evolutionary biology: a basic science for psychiatry?

Evolutionary biology has much to offer psychiatry. It distinguishes between ultimate and proximate explanations of behavior and addresses the functional significance of behavior. Subtheories, frequently voiced misconceptions, specific applications, testable hypotheses and limitations of evolutionary theory are reviewed. An evolutionary perspective is likely to improve understanding of psychopathology, refocus some clinical research, influence treatment and help integrate seemingly unrelated findings and theoretical explanations.

Plasma catecholamines and social behavior in male vervet monkeys (Cercopithecus aethiops sabaeus)

Many investigations in humans indicate that epinephrine, norepinephrine and their ratio may correlate with such traits as social competence, academic achievement, and aggression. However, the socioeconomic, dietary, and environmental confounds accompanying most human studies complicate their interpretation. Social status, aggression, and other social behaviors can be reliably assessed in nonhuman primates under conditions controlling for crucial environmental factors. If interpretation of human studies is correct, dominant and subordinate male vervet monkeys should exhibit distinctive patterns of catecholamine secretion. To test this possibility, seventeen adult male monkeys living in six stable social groups were observed for 6 months. Based on their success in agonistic events, subjects were categorized as dominant or subordinate. Alpha scores were calculated from empirically derived factors to provide a noncategorical measure of dominant behavioral style. Plasma epinephrine and norepinephrine samples obtained from anesthetized subjects did not differ between dominant and subordinate males. Alpha scores, however, distinguished high from low norepinephrine/epinephrine ratio groups. These findings are consistent with studies in humans linking high epinephrine, low norepinephrine, and social competence.

Fenfluramine effects on serotonergic measures in vervet monkeys

Chronic fenfluramine treatment reduced whole blood serotonin and CSF 5-hydroxyindoleacetic acid, but increased aggressive and locomotor behavior, in adult male vervet monkeys (Cercopithecus aethiops sabaeus). Following a drug-free washout period to monitor the drug recovery course, we initiated a second period of fenfluramine treatment in the same animals. When whole blood serotonin concentrations were reduced by about 40% from predrug baseline levels, we examined 11 cortical and subcortical brain regions for their content of 5-hydroxytryptamine, 5-hydroxyindoleacetic acid, norepinephrine, and dopamine. We observed correspondence between the reduction in whole blood serotonin and the reduction in brain 5-hydroxytryptamine. Similarly, there was a correspondence between the reduced 5-hydroxyindoleacetic acid levels observed in CSF and brain. No alterations were noted in the concentrations of norepinephrine or dopamine. These observations suggest that the behavioral effects observed in monkeys after chronic fenfluramine treatment result from reduced central serotonin.

Serotonergic mechanisms promote dominance acquisition in adult male vervet monkeys

In a counter-balanced, cross-over study, we examined the contributions of serotonergic systems to the acquisition of social dominance in adult male vervet monkeys. Subjects were members of 12 social groups, each containing 3 adult males, at least 3 adult females, and their offspring. Animals were observed in 5 intervals including a first baseline, a first experimental, a second baseline, a second experimental, and a third baseline period. At the end of the first baseline period, the dominant male was removed from each group. In each group, one of the two remaining subordinate males was selected at random for treatment and during the first experimental period, 6 of the 12 treated males received drugs that enhanced serotonergic activity (3 were given tryptophan 40 mg/kg/day and 3 fluoxetine 2 mg/kg/day). The other 6 treated males received drugs that reduced serotonergic function (3 were given fenfluramine 2 mg/kg/day and 3 cyproheptadine 60 micrograms/kg/day). At the end of the first experimental period, the original dominant male was returned to his group and the second baseline period began. In all instances, the originally dominant male regained his dominant position. The second experimental period began with the dominant male again being removed and, the 12 treated males were given the treatment they had not received in the first experimental period. At the start of the third 12-week baseline period, the original dominant male was returned to his group and resumed his dominant status. When the 12 treated subjects received tryptophan or fluoxetine, they became dominant in all instances. When they received fenfluramine or cyproheptadine, their vehicle-treated cage mates became dominant. The sequence of the behavioral changes shown by the treated males as they acquired dominance status paralleled those seen in naturalistic conditions. These observations support the distinction between dominance and aggression and strongly suggest that when hierarchical relationships are uncertain, serotonergic mechanisms may mediate the behaviors which permit a male to attain high dominance status.

Long-term effects of early mothering behavior on responsiveness to the environment in vervet monkeys

The long-term effect of early mothering style on juvenile responsiveness to the external environment was studied in vervet monkeys living in two naturally composed, undisturbed social groups. Mothering behavior for 35 mother-infant dyads was analyzed by principal components analysis which revealed two independent dimensions: protectiveness and rejection. Protectiveness was characterized by high levels of approach, making contact, restraint, and inspection from mother to infant, and rejection was associated with high levels of rejection, breaking contact, and leaving. When observed as yearlings and 2-year-olds, juveniles who had had more protective early mothering showed less interest in the external environment, as measured by the percentage of time they spent looking outside the home enclosure. They also took longer to enter a completely novel environment compared to juveniles who had had less protective mothers. Maternal rejection was not significantly associated with looking out or with latency to enter the novel environment. These results were independent of the effects of age, sex, and dominance rank on behavior.

On the possibility of ethological explanations of psychiatric disorders

This paper discusses: previous ethological and evolutionary explanations of psychiatric disorders; a behavior-physiology interaction framework for explaining the frequency and course of selected psychiatric illnesses; atypical behavioral capacities among persons with psychiatric disorders; behavioral mechanisms; and ethological explanations of the behavior of patients suffering from psychiatric illnesses. The importance of behavior-physiology interactions is emphasized. Possible consequences of current taxonomic systems (DSM-III) are considered. It is concluded that ethology has a vital role in increasing our understanding of psychiatric disorders through identifying: characteristics of disorders; selected causes; degree and type of compromised mechanisms; and, intervention effectiveness.

Comparison of ketamine, physical restraint, halothane and pentobarbital: lack of influence on serotonergic measures in monkeys and rats

The consequences of the use of ketamine for immobilization have been examined on the concentration of whole blood serotonin, concentrations of neurotransmitters and metabolites in CSF and brain, and specific binding of ligands related to neurotransmitters in brain. Vervet monkeys (Cercopithecus aethiops sabaeus) were examined under conditions which compared ketamine with physical restraint and with halothane. It was found that ketamine, used acutely in monkeys for restraint, had no influence on the concentration of serotonin in whole blood or the concentration of 5-hydroxyindoleacetic acid or homovanillic acid in the CSF. In rats, untreated animals were compared with those treated with ketamine alone, or in conjunction with pentobarbital. Treatment with ketamine had no influence on the specific binding of ketanserin, imipramine, prazosin or dihydroalprenolol in brain of rat, nor any influence on the concentrations of serotonin, 5-hydroxyindoleacetic acid, norepinephrine, epinephrine, dopamine, or dihydroxyphenylacetic acid in brain. A moderately increased concentration of homovanillic acid was observed in several areas of the brain of the rat after ketamine alone or paired with pentobarbital.

Whole-blood serotonin in premenstrual syndrome

Whole-blood serotonin levels in 14 subjects with well documented premenstrual syndrome and 13 age-matched controls were compared. Serotonin levels of premenstrual syndrome subjects were significantly lower during the last ten days of the menstrual cycle. No significant differences were noted in levels of serum estradiol and progesterone. Decreased serotonin is known to be associated with depression in humans, and nonhuman primates have exhibited abnormal behavioral profiles when given serotonin antagonists. The present observation suggests that the physiologic basis of premenstrual syndrome involves an alteration in serotonin metabolism.

Vervet monkey (Cercopithecus aethiops sabaeus) whole blood serotonin level is determined by platelet uptake sites

Whole blood serotonin levels in adult male vervet monkeys living in social groups are sensitive to the animals' social environment. The mechanisms that translate different behavioral and environmental cues into altered whole blood serotonin levels are unknown. In this study, we have measured platelet number, size, serotonin content, and serotonin uptake, as well as the serum concentrations of tryptophan, Mg+2 and Ca+2. Results showed that whole blood serotonin levels, platelet serotonin content, and the serotonin uptake parameter Vmax were stable within animals on repeated sampling. The whole blood serotonin level was highly positively associated with platelet serotonin content, and the platelet serotonin content was highly positively associated with Vmax. These findings suggested that whole blood serotonin levels were a function of the number of platelet uptake sites.

Similarity of 5-HT2 receptor sites in dominant and subordinate vervet monkeys

Pharmacological studies using serotonergic agents have revealed status-linked behavioral effects in dominant and subordinate vervet monkeys. A possible explanation for the greater drug response observed in dominant animals is that there is a CNS difference between dominant and subordinate animals. Such differences could exist at the level of serotonin receptor sites, membrane responsiveness, or interaction with other neurotransmitters. We have examined the specific 3H-ketanserin binding in various regions of vervet monkey brain to evaluate the hypothesis that dominant and subordinate vervet monkeys differ in CNS 5-HT2 receptor sites. No differences were found in the number or affinity of 3H-ketanserin binding sites between dominant and subordinate animals. Further, no differences were found in the displacement of 3H-ketanserin binding by the serotonin agonist quipazine. These results suggest the conclusion that differences at 5-HT2 binding sites do not account for status-linked differences in behavioral drug response in vervet monkeys and that other or additional mechanisms must underlie status-related drug response differences.

Unrealistic wishes and physiological change. An overview

This paper examines postulated relationships between physiological change and unrealistic wishes in a population of women with histories of depression. Findings are discussed within an evolutionary framework with emphasis on species-typical functions of imagining, and postulated interactions between behavior, imagining, unrealistic wishes and physiological systems. The ideas developed may be of interest to psychoanalysts in that they appear to increase the breadth and precision of psychoanalytic interpretations.

Resting cortisol levels and the emergence of dominant status among male vervet monkeys

Resting serum cortisol was measured in adult male vervet monkeys (Cercopithicus aethiops sabaeus) in four different conditions: (1) among groups with unaltered group membership and established dominance hierarchies; (2) among groups from which the original dominant male had been removed and in which the remaining males competed for dominant status; (3) among newly formed groups of three unfamiliar males each of which had been the dominant male in his previous group; and (4) among groups from which a dominant male was temporarily separated and returned. In Condition 1, cortisol concentrations did not differ between dominant and subordinate males. The second condition showed that cortisol levels were highest among males who eventually emerged as the dominant male. In the third condition, however, cortisol levels did not differentiate eventually dominant from eventually subordinate males. In the last condition, cortisol levels were highest in the animals that became or remained dominant following reintroduction. These data indicate that cortisol concentration does not differ between dominant and subordinate males in stable groups and that cortisol rises during competition for dominance among familiar males.

Effects of chronic fenfluramine on blood serotonin, cerebrospinal fluid metabolites, and behavior in monkeys

The effects of long term (70 days) fenfluramine treatment on selected physiological and behavioral measures were examined in four adult male vervet monkeys (Cercopithecus aethiops sabaeus). Relative to pretreatment baseline values, whole blood serotonin (WBS) and cerebrospinal fluid 5-hydroxyindole acetic acid (5-HIAA) were reduced, cerebrospinal fluid homovanillic acid (HVA) was unaltered, and aggressive and locomotor behavior were increased. Both physiological and behavioral effects were reversible: all measures returned to baseline values in the 35 day post-treatment period, with WBS resuming pretreatment values more rapidly than CSF 5-HIAA. At the relatively low doses (1-4 mg/kg/day) employed in the present study fenfluramine produced behavioral effects similar to those resulting from PCPA and opposite to those following tryptophan administration. Thus the behavioral effects of long-term fenfluramine may involve reductions in serotonergic transmission.

Dominant social status facilitates the behavioral effects of serotonergic agonists

The effects of dominance rank on the behavioral responses to drugs that enhance central serotonergic function were examined in 45 adult male vervet monkeys living in 15 stable social groups. Each group contained 3 adult males, 3 adult females, and their immature offspring. Dominance rank was assessed by measuring success in intermale agonistic encounters. In every group one male was clearly the dominant, or alpha male, and the other two males were subordinate. Males from 5 groups received 3 doses of the serotonin reuptake inhibitor fluoxetine (0.5, 1.0 and 2.0 mg/kg/day); those from a second set of 5 groups received 3 doses of the receptor agonist quipazine (0.25, 0.50 and 1.0 mg/kg/day); those from a third set of 5 groups received the serotonin precursor tryptophan (10, 20 and 40 mg/kg/day). The 3 drug treatments produced strikingly similar behavioral effects. Each produced dose-dependent increases in approaching, grooming, resting and eating and decreases in locomoting, avoiding, being vigilant and being solitary. Dominant males were significantly more responsive behaviorally to all 3 drugs than were subordinate males: the increase or decrease in each behavioral measure was larger in dominant than in subordinate males. In combination with previous studies, these data suggest that dominant and subordinate males differ in the drug sensitivity of their serotonergic systems.

Serum testosterone, male dominance, and aggression in captive groups of vervet monkeys (Cercopithecus aethiops sabaeus)

The relationship of serum testosterone concentration to male dominance rank and frequency of aggression was investigated in stable vervet monkey social groups, each containing two or three adult males, several adult females, and their offspring. Dominance relationships were determined by noting an animal's success in intermale aggressive encounters. A striking finding was the marked within-subject variation in testosterone concentration: 5- to 10-fold fluctuations were often observed on successive days. When all 15 groups were considered together, testosterone concentration was unrelated to dominance rank. Although mean testosterone concentration for all dominant males was higher than the mean for all subordinate males, this difference was not significant. In a subset of 4 groups, the rate of aggression initiated was significantly correlated with same-day testosterone in dominant but not in subordinate males.

Rapid communication whole blood serotonin and the type A behavior pattern

In 72 young males, whole blood serotonin is shown to have a pronounced relationship with the Type A behavior pattern. The relationship is explored with multivariate statistical techniques.

Social and environmental influences on blood serotonin concentrations in monkeys

Dominant male adult vervet monkeys have whole-blood serotonin concentrations approximately twice those of subordinate adult males. We examined the effects of spontaneous and induced changes in social status, temporary isolation from the social group, and membership in single male groups on whole-blood serotonin concentrations. We found that in male vervet monkeys, elevated blood serotonin concentration is a state-dependent consequence of active occupation of the dominant male social position, and we believe that a reinterpretation of the significance of hyperserotonemia in humans may be warranted.