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Biomedical subjects

N D Ryan

Publications and source records attributed to N D Ryan.

At least 55 records · Page 3Linked to original sources
PubMed1996

Corticotropin-releasing hormone challenge in prepubertal major depression.

This study investigates cortisol and ACTH (corticotropin) responses to an infusion of human CRH (corticotropin-releasing hormone) in prepubertal children with major depressive disorder (MDD). Following a period of 24 hours of adaptation to the laboratory environment with an intravenous catheter in place, 34 children with MDD and 22 healthy controls received 1 microgram/kg of human CRH at 5:00 PM. Blood samples for cortisol and ACTH were measured at baseline and post-CRH. Overall, there were no significant differences between the MDD and the normal controls in baseline or post CRH stimulation values of either cortisol or ACTH. Melancholic (n = 4) patients had significantly higher baseline cortisol levels than nonmelancholic (n = 24) patients. Compared with the outpatients and the nonmelancholics, the inpatients (n = 10) and the melancholics showed significantly lower total ACTH secretion (effect size: 0.9 and 1.4, respectively) after CRH infusion. These results are consistent with a broad literature suggesting that the HPA axis abnormalities occur less frequently in early-onset depression than reported in adult studies. The pattern of results in the subgroups of inpatients and in melancholic children, however, raise questions about possible continuities with adult studies.

Adolescent↗
PubMed1996

Nocturnal ACTH, cortisol, growth hormone, and prolactin secretion in prepubertal depression.

OBJECTIVE: To examine nocturnal secretion of adrenocorticotropin, cortisol, growth hormone, and prolactin in 38 medically healthy children with prepubertal major depression compared with 28 medically and psychiatrically healthy control children. METHOD: Prior to sampling, subjects underwent an "adaptation night" with the intravenous catheter in place and electroencephalographic (EEG) electrodes for standard all-night polysomnogram. On the following night, plasma samples were obtained every 20 minutes through an indwelling catheter. Hormonal concentrations were measured by specific radioimmunoassay and aligned by EEG-confirmed sleep onset. Areas under the curve were calculated for total secretion and compared using analysis of variance. RESULTS: Prepubertal depressed children had lower cortisol secretion during the first 4 hours after sleep onset compared with controls. Adrenocorticotropin, prolactin, and growth hormone secretion did not differ between groups. Examination of clinical characteristics in depressed children revealed lower nocturnal adrenocorticotropin concentrations in depressed inpatients versus depressed outpatients and in depressed sexually abused versus depressed nonabused children. A significant sex by diagnosis effect revealed lower growth hormone secretion in depressed females compared with depressed males. CONCLUSIONS: In contrast to neuroendocrine challenge studies in these same subjects, nocturnal neuroendocrine measures did not reveal any of the expected group differences. These results emphasize the contrasts between unstimulated and challenge studies of neuroendocrine secretion and of the importance of considering clinical characteristics and maturation influences in biological studies of prepubertal depression.

Adolescent↗
PubMed1996

A randomized, controlled trial of amitriptyline in the acute treatment of adolescent major depression.

OBJECTIVE: To determine amitriptyline's (AMI) efficacy in the acute treatment of adolescent major depressive disorder (MDD). METHOD: Subjects aged 12 through 17 years meeting Research Diagnostic Criteria for MDD, diagnosed with the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS), participated in a 2-week placebo-washout followed by an 8-week, randomized, double-blind, parallel-design, placebo-controlled trial of AMI, 5 mg/kg per day. The K-SADS nine-item scale, the Hamilton Depression Rating Scale, and the Clinical Global Impressions rating scale were used as outcome measures. RESULTS: Thirty-one subjects were randomized (18 AMI, 13 placebo). Twenty-two subjects were study completers (12 AMI, 10 placebo). AMI's efficacy was suggested by the Clinical Global Impressions but not the K-SADS-derived data. Perhaps the primary limitation of the current study is its small sample size. CONCLUSION: No definitive recommendation can be made regarding the efficacy of tricyclic antidepressants in the treatment of adolescent MDD.

Adolescent↗
PubMed1996

Childhood and adolescent depression: a review of the past 10 years. Part I.

OBJECTIVE: To qualitatively review the literature of the past decade covering the epidemiology, clinical characteristics, natural course, biology, and other correlates of early-onset major depressive disorder (MDD) and dysthymic disorder (DD). METHOD: A computerized search for articles published during the past 10 years was made and selected studies are presented. RESULTS: Early-onset MDD and DD are frequent, recurrent, and familial disorders that tend to continue into adulthood, and they are frequently accompanied by other psychiatric disorders. These disorders are usually associated with poor psychosocial and academic outcome and increased risk for substance abuse, bipolar disorder, and suicide. In addition, DD increases the risk for MDD. There is a secular increase in the prevalence of MDD, and it appears that MDD is occurring at an earlier age in successive cohorts. Several genetic, familial, demographic, psychosocial, cognitive, and biological correlates of onset and course of early-onset depression have been identified. Few studies, however, have examined the combined effects of these correlates. CONCLUSIONS: Considerable advances have been made in our knowledge of early-onset depression. Nevertheless, further research is needed in understanding the pathogenesis of childhood mood disorders. Toward this end, studies aimed at elucidating mechanisms and interrelationships among the different domains of risk factors are needed.

Adolescent↗
PubMed1996

Childhood and adolescent depression: a review of the past 10 years. Part II.

OBJECTIVE: To review the literature of the past decade covering the assessment, treatment, and prevention of early-onset major depressive disorder (MDD) and dysthymic disorder (DD). METHOD: A computerized search for articles published during the past decade was made, and selected studies are presented. RESULTS: Diagnostic systems and standardized interviews have been developed to reliably assess and diagnose early-onset MDD and DD. To data, few controlled psychotherapeutic trials, in particular cognitive-behavioral therapy (CBT), and one study using fluoxetine have been shown to be efficacious in the acute management of early-onset MDD. While studies of tricyclic antidepressants have shown no difference between medication and placebo, these studies are inconclusive because of the inclusion of small samples and other methodological issues. CBT may also be useful for the prevention of MDD. No studies have been published on maintenance treatment of MDD or the treatment of early-onset DD. CONCLUSIONS: It appears that both pharmacological and psychotherapeutic interventions have a role in the acute treatment of MDD. However, further research on the separate and combined efficacy of these treatments for the acute treatment, maintenance, and prevention of early-onset MDD and DD is needed. The impact of comorbidity and psychosocial consequences of early-onset depression also emphasize the importance of utilizing a multimodal approach to treatment.

Adolescent↗
PubMed1995

Stressful life events and EEG sleep in depressed and normal control adolescents.

EEG sleep measures in 35 depressed and 33 normal control adolescents were examined in relation to stressful life events occurring in the year before sleep studies. There was a significant interaction between stressful life events and diagnostic status for REM latency and total REM time. In the normal controls, the presence of stressful life events was significantly associated with reduced REM latency and increased total REM time. Among the depressed adolescents, there were no significant effects of stressful life events on REM latency or total REM time. The depressed adolescents with no stressful life events (n = 9) had significantly lower REM latency values compared to normal control adolescents with no stressful life events (n = 13)(61.7 +/- 50.0 vs. 132.1 +/- 79.0, p < or = .01). It appears that stressful life events influence at least some measures of adolescent sleep and should be considered in future controlled studies aimed at understanding sleep changes in adolescent depression.

Adolescent↗
PubMed1995

Unipolar depression in adolescents: clinical outcome in adulthood.

OBJECTIVE: This study examined the longitudinal clinical course and adult sequelae of adolescent unipolar major depressive disorder (MDD) using a controlled longitudinal design. METHOD: Subjects were 28 adolescents (15.4 +/- 1.3 years) with systematically diagnosed unipolar MDD and 35 group-matched control subjects who participated in a cross-sectional electroencephalogram sleep and neuroendocrine study. Using standardized instruments, interviewers who were blind to subjects' initial diagnoses conducted follow-up clinical assessments 7.0 +/- 0.5 years later in 94% of the original cohort. RESULTS: The depressed group showed high rates of recurrence of MDD episodes during the interval period (69%). They also had elevated rates of new-onset bipolar disorder (19%). Twenty-three percent of subjects with an initial diagnosis of MDD had no additional depressive episodes after the index assessment. The rate of new onset of depression in the controls was 21%. Low socioeconomic status predicted recurrence of depressive episodes in the MDD group. MDD subjects with recurrence(s) and controls with new onset of depression during the follow-up period had significant psychosocial morbidity, as evidenced by disruption in interpersonal relationships and dissatisfaction with life and decrease in global functioning, compared with both MDD subjects with no further episodes and control subjects who had never been psychiatrically ill. These psychosocial deficits persisted remission from depressive episode(s). CONCLUSIONS: Adolescent unipolar MDD predicts continued risk for recurrences with persistence of depressive episodes and psychosocial morbidity into adulthood. A sizable minority, however, have sustained periods of remission associated with good social adjustment.

Adolescent↗
PubMed1995

Stressful life events in depressed adolescents: the role of dependent events during the depressive episode.

OBJECTIVE: To examine the relationship between stressful life events and major depressive disorder (MDD) in adolescents. METHOD: Adolescents (aged 12 to 18 years) with a current episode of MDD based on Research Diagnostic Criteria (n = 39) and normal controls free of any Axis I lifetime psychiatric disorder (n = 35) were assessed using the Life Events Record. RESULTS: MDD and normal control adolescents had similar rates of total stressful life events in the year before being interviewed. Stressful life events were dichotomized into those that were most likely either independent of or dependent on the adolescent's influence/behavior. Depressed adolescents had significantly more dependent stressful life events during the previous year than did the normal controls. Further analyses showed that depressed adolescents with dependent stressful life events scored lower on symptom clusters and accordingly were less severely depressed than depressed adolescents without dependent life events. CONCLUSIONS: The results of this study indicate that depressed adolescents have an increased risk for experiencing dependent life events. Furthermore, these data suggest that dependent life events in depressed adolescents are differentially associated with the type and severity of symptom presentation. The temporal occurrence, severity, and type of stressful life events as they relate to the onset, phenotypic expression, and maintenance of depression in adolescents need to be more fully understood.

Adolescent↗
PubMed1995

A case-control family history study of depression in adolescents.

OBJECTIVE: To examine whether depression aggregates in the families of depressed adolescents and to determine whether clinical features and/or comorbid syndromes in the depressed adolescents change the risk of psychopathology in relatives. METHOD: Lifetime prevalence rates of psychopathology in the first-degree (n = 228) and second-degree (n = 736) relatives of 76 adolescents with major depressive disorder (MDD) and the first-degree (n = 107) and second-degree (n = 323) relatives of 34 normal control adolescents were assessed by the Family History-Research Diagnostic Criteria (FH-RDC) method using the parent/guardian as the family informant. RESULTS: Compared with the first-degree relatives of normal controls, the relatives of depressed adolescents had significantly higher lifetime rates of MDD (25% versus 13%) and "any" of the FH-RDC psychiatric disorders (53% versus 36%). The second-degree relatives of adolescents with MDD had significantly higher lifetime rates of FH-RDC "other" psychiatric disorder (12% versus 7%) and "any" of the FH-RDC psychiatric disorders (22% versus 15%) but not MDD (5% versus 6%) compared with the relatives of normal controls. The first-degree relatives of depressed adolescents who were also suicidal had increased lifetime rates of suicidal behavior which significantly cosegregated with MDD. Comorbid conduct disorder in the depressed adolescent was associated with increased rates of antisocial personality disorder in the first-degree relatives and also tended to cosegregate with MDD. CONCLUSIONS: The current study provides further evidence for the familial aggregation of depression in adolescent-onset MDD. This study also suggests that the familial aggregation of nonaffective psychiatric disorders depends on the clinical features and comorbid syndromes present in the depressed adolescent proband.

Adolescent↗
PubMed1995

Estimation of the association between desipramine and the risk for sudden death in 5- to 14-year-old children.

BACKGROUND: Four cases of sudden death in children 12 years or younger during desipramine treatment were identified between 1986 and 1992. We evaluated whether these events support the hypothesis that exposure to therapeutic doses of desipramine contributes to the risk for sudden death in otherwise healthy children. METHOD: The National Center for Health Statistics provided the baseline number of sudden unexplained deaths in children 5 to 14 years old. Data from the National Disease and Therapeutic Index were used to estimate the exposure to desipramine in children in the same age group. Since two of the four deaths were identified by 1987, we used the post-1987 experience as if it were a prospective period in which a causal association could be examined. RESULTS: The number of sudden deaths in desipramine-exposed children did not increase from 1986 to 1992 despite a marked increase in exposure. By using 4 to 6 months as the average lifetime of a desipramine prescription and a baseline rate of sudden death of 4.2 deaths/million/year in this population, the post-1987 period would account for 162,000 to 242,000 person-years of desipramine exposure. Although not statistically significant, this level of exposure corresponds to a relative risk of 2.1 (95% CI = 0.5 to 15) to 3.1 (95% CI = 0.8 to 22). CONCLUSION: Although, based on our estimates, the evidence for an association between desipramine and sudden death in children aged 5 to 14 years appears weak, replication of our findings is needed with a more precise numerator (total number of deaths) and denominator (the appropriate conversion from drug appearance to actual exposure) before a firm conclusion on this subject can be drawn. Until then, even if remote, the possibility of an association between desipramine and sudden death in children stresses the importance of assessing risks and benefits when desipramine is used in pediatric patients.

Adolescent↗
PubMed1994

Exercise training and nutritional supplementation for physical frailty in very elderly people.

BACKGROUND: Although disuse of skeletal muscle and undernutrition are often cited as potentially reversible causes of frailty in elderly people, the efficacy of interventions targeted specifically at these deficits has not been carefully studied. METHODS: We conducted a randomized, placebo-controlled trial comparing progressive resistance exercise training, multinutrient supplementation, both interventions, and neither in 100 frail nursing home residents over a 10-week period. RESULTS: The mean (+/- SE) age of the 63 women and 37 men enrolled in the study was 87.1 +/- 0.6 years (range, 72 to 98); 94 percent of the subjects completed the study. Muscle strength increased by 113 +/- 8 percent in the subjects who underwent exercise training, as compared with 3 +/- 9 percent in the nonexercising subjects (P < 0.001). Gait velocity increased by 11.8 +/- 3.8 percent in the exercisers but declined by 1.0 +/- 3.8 percent in the nonexercisers (P = 0.02). Stair-climbing power also improved in the exercisers as compared with the nonexercisers (by 28.4 +/- 6.6 percent vs. 3.6 +/- 6.7 percent, P = 0.01), as did the level of spontaneous physical activity. Cross-sectional thigh-muscle area increased by 2.7 +/- 1.8 percent in the exercisers but declined by 1.8 +/- 2.0 percent in the nonexercisers (P = 0.11). The nutritional supplement had no effect on any primary outcome measure. Total energy intake was significantly increased only in the exercising subjects who also received nutritional supplementation. CONCLUSIONS: High-intensity resistance exercise training is a feasible and effective means of counteracting muscle weakness and physical frailty in very elderly people. In contrast, multi-nutrient supplementation without concomitant exercise does not reduce muscle weakness or physical frailty.

Aged↗
PubMed1994

The 24-hour pattern of prolactin secretion in depressed and normal adolescents.

Plasma prolactin concentrations were measured at 20-min intervals over a 24-hr period in 49 adolescents with major depressive disorder (MDD) and 39 normal control adolescents. Neither the pattern nor the amount of prolactin secretion was significantly different between these two groups. There were significant gender differences, with girls secreting more prolactin than boys, but no significant gender-by-diagnosis interactions were found. With the possible exception of psychosis, dividing the MDD sample based on clinical characteristics failed to reveal differences. These findings are discussed in the context of changes in prolactin in childhood depression using a serotonergic challenge study, as well as in relation to baseline prolactin studies in adult depression.

Adolescent↗
PubMed1994

Cholinergic REM induction test with arecoline in depressed children.

Children with major depressive disorder often fail to exhibit electroencephalographic (EEG) sleep abnormalities similar to those reported in depressed adults. It was hypothesized that a cholinergic rapid eye movement (REM) induction test would contribute to the identification of EEG sleep abnormalities in depressed children. To test this hypothesis, prepubertal children meeting research diagnostic criteria for major depressive disorder (n = 33) and carefully screened healthy control children (n = 15) were enrolled in a 4-day psychobiologic protocol that included 1 night with infusion of arecoline (0.5 mg) during the first non-REM sleep period. Although there had been no significant group differences in baseline sleep measures, results on the arecoline night revealed significantly shorter REM latency in the group of depressed children compared with the control children (mean +/- SD = 105 +/- 51 minutes vs. 140 +/- 46 minutes). The design of the protocol (with an interval break immediately preceding the arecoline night) prevented a direct estimation of arecoline effects within subjects; however, these data provide promising preliminary results regarding cholinergic REM induction tests in childhood depression.

Aging↗
PubMed1994

Cellular immunity in depressed, conduct disorder, and normal adolescents: role of adverse life events.

OBJECTIVE: To determine whether adolescents with major depressive disorder have disturbances in their cellular immunity and to study whether the immunological changes detected are specific to depression or are general responses to stress. METHOD: Twenty subjects with major depressive disorder, 17 nondepressed subjects with conduct disorder, and 17 normal adolescents were recruited. Subjects were assessed with a clinical interview for DSM-III-R and a modified version of the Coddington Life Events Checklist. Blood samples were drawn for total white blood cells, lymphocytes subsets, natural killer cell activity, lymphocyte proliferation response to phytohemagglutinin, and cortisol plasma levels. RESULTS: Overall, there were no significant between-group differences in any of the cellular immune measurements. Natural killer cell activity was significantly negatively correlated with past year and lifetime adverse life events across all effector-target cell ratios. Controlling for diagnoses and socioeconomic status yielded similar results. There were no significant effects of age, sex, race, sleep, nutrition, cigarette use, menstrual cycle, or cortisol on any of the immunological variables. CONCLUSIONS: In this sample of adolescents, we found that independent of the diagnoses and socioeconomic status, increases in adverse life events were associated with low natural killer cell activity.

Adolescent↗
PubMed1993

The psychosocial functioning and family environment of depressed adolescents.

OBJECTIVE: This study examined measures of functional impairment and family relations in a sample of 62 adolescents with major depressive disorder (MDD) and 38 normal controls with no history of psychiatric illness. METHOD: Ratings of the following domains were obtained: mother-child relations, father-child relations, spousal relations, sibling relations, peer relations, and school performance. Ratings of each domain for the 3-month period preceding the assessment were derived from information obtained using a semistructured interview administered independently to the adolescents and one of their parents. RESULTS: Adolescents with MDD were found to have severe difficulties in all areas. Ninety percent of the depressed adolescents had scores greater than 2 SD above the mean of the normal controls on one or more of the domain ratings. In addition, adolescents with difficulties in parent-child relations were more likely than those adolescents without problems in family relations to have difficulties in peer relations and school performance. CONCLUSIONS: The authors discuss the importance of systematically examining psychosocial variables in future studies of the etiology, course, and treatment of MDD in adolescents.

Adolescent↗
PubMed1992

The dexamethasone suppression test in children and adolescents: a review and a controlled study.

Dexamethasone Suppression Test (DST) studies conducted in children and adolescents are reviewed, together with factors hypothesized to explain discrepancies in rates of DST nonsuppression across studies. These factors are then examined in a controlled study of 27 adolescents with major depressive disorder (MDD) and 34 normal controls (NC). Subjects were given 1 mg of dexamethasone at 11:00 PM, and the following day serum samples for cortisol were collected each hr from 8 AM to 11 PM through an indwelling catheter. There were no significant differences found between the MDD and NC subjects on any postdexamethasone cortisol measure. Further, cortisol suppressors and nonsuppressors were not distinguished by any of the hypothesized factors identified from the review, including inpatient status, presence of suicidality, endogenous features, psychotic symptoms, or prior history of MDD. Questions about the appropriateness of the 1 mg dose of dexamethasone (currently the standard dose used with adolescents) are raised, together with a discussion of the effects of stress on DST findings.

Adolescent↗
PubMed1992

Nocturnal urinary excretion of 6-hydroxymelatonin sulfate in prepubertal major depressive disorder.

Levels of the melatonin metabolite, 6-hydroxymelatonin sulfate, were measured in overnight urine from 31 prepubertal children with major depressive disorder and 15 normal control children with very low family loading for affective disorder. The two groups did not differ with regard to their nocturnal excretion of this compound, nor was any depressive subgroup identified whose 6-hydroxymelatonin sulfate excretion differed from that of the control group. Previous studies of pineal function in depression are reviewed and discussed in the context of the present investigation.

Adolescent↗