Biomedical subjects

N D Ryan

Publications and source records attributed to N D Ryan.

At least 19 recordsLinked to original sources

PubMed2004

Measuring aerobic fitness of Hispanic youth 10 to 12 years of age.

Obesity is a major health problem in the U.S., especially for Hispanic youth. Because maximal/peak oxygen consumption (V.O (2)peak) is one predictor of future weight gain in children, valid field-based methods for determining V.O (2)peak in Hispanic children are needed. The purpose of this study was to validate a field-based aerobic fitness test, the 20-m shuttle test (20-MST), in Hispanic boys (n = 58) and girls (n = 67), 10 - 12 years old (mean age +/- SD, 10.7 +/- 0.6 y). Measured V.O (2)peak was determined during a maximal, graded treadmill test using the Bruce protocol. The 20-MST was administered per a standard protocol. Maximal speed attained on the 20-MST and age were used to estimate V.O (2)peak. An intraclass coefficient of 0.82 was obtained on 35 students (16 boys; r = 0.85 and 19 girls; r = 0.79) who completed the 20-MST twice, 1-wk apart. Estimated (44.3 ml x kg (-1) x min (-1) ) and measured (45.1 ml x kg (-1) x min (-1)) V.O (2)peak were not significantly different (p = 0.33). The correlation between the two V.O (2)peak parameters was r = 0.62; p < 0.001, the standard error of the estimate (SEE) was 3.91 ml x kg (-1) x min (-1), and 85.5 % of the measured V.O (2)peak values fell within 5.9 ml x kg (-1) x min (-1) of estimated V.O (2)peak. The weight status of the child did not significantly change these results. The 20-MST combined with the Leger et al. equation is a valid method for predicting V.O (2)peak in Hispanic youth. The test can be used to provide valuable information for intervention design and disease prevention.

Aerobiosis↗

PubMed2001

Diagnosing pediatric depression.

This review examines current instrumentation for making clinical and research diagnoses of depressive disorders in children and adolescents. Reliable assessment of depression in children requires gathering information from both the parent and child, as well as from all other available information. The methodology for obtaining information from the child must be adapted to reword and better obtain information in those domains that are inherently difficult for children, including questions about internal affect state and questions requiring judgment. Because child depression is highly comorbid with other psychiatric disorders, including anxiety, attention-deficit/hyperactivity disorder (ADHD), and conduct disorder (CD), it is imperative that these and other psychiatric disorders be simultaneously assessed. A number of structured and semistructured instruments address this task well. More work is needed to decrease the time burden and cost of reliable assessment of child depression.

Adolescent↗

PubMed2001

Premorbid polysomnographic signs in depressed adolescents: a reanalysis of EEG sleep after longitudinal follow-up in adulthood.

BACKGROUND: This is a report of a clinical follow-up study (10-15 years later as young adults) of adolescent major depressives and normal control subjects. Polysomnographic data were obtained during the original study period when the subjects were adolescent (time 1). With clinical follow-up (time 2) assessments in hand, our objective was to ascertain whether there were any premorbid polysomnographic signs associated with depression during adolescence. METHODS: Based upon initial (during adolescence) and follow-up clinical assessments (as adults), new subject groupings were generated: depression-free normal subjects and original normal subjects who experienced a depressive episode during the follow-up period (latent depressives). Suicidality and recurrence of depression were also examined. Multivariate analysis of covariance was used to analyze group differences in sleep measures and logistic regression for predicting three outcomes: lifetime depression, lifetime suicidality, and recurrence. RESULTS: Comparison of the depression-free normal subjects, the latent depressives, and the original major depressives revealed significant differences for sleep latency and sleep period time. Comparing all lifetime depressives (original major depressives and the latent depressives) to depression-free normal subjects revealed significantly more stages 3 and 4 combined (ST34) sleep and greater sleep period times among the depressives. An analysis involving the presence or absence of suicidality revealed no overall significant differences between the groups. Comparison of the lifetime depressives grouped by nonrecurrent and recurrent depressive course to the depression-free normal subjects revealed significant difference for sleep period time. Using logistic regression, we found that a longer sleep latency and sleep period time significantly predicted lifetime depression. Gender, ST34 sleep, and an interaction term for ST34 sleep and REM latency significantly predicted lifetime suicidality. CONCLUSIONS: There was evidence of premorbid sleep abnormalities during adolescence. A general pattern of sleep disruption around sleep onset and during the first 100 min of the sleep period and overall sleep was evident among the major and lifetime depressives, involving sleep latency (initial insomnia), sleep period time (hypersomnia), REM latency, and slow-wave sleep. This adds to the body of literature that highlights the importance of the first 100 min of the sleep period in depression.

Adolescent↗

PubMed2001

Amygdala response to facial expressions in children and adults.

BACKGROUND: The amygdala plays a central role in the human response to affective or emotionally charged stimuli, particularly fear-producing stimuli. We examined the specificity of the amygdala response to facial expressions in adults and children. METHODS: Six adults and 12 children were scanned in a 1.5-T scanner during passive viewing of fearful and neutral faces using an EPI BOLD sequence. All scans were registered to a reference brain, and analyses of variance were conducted on the pooled data to examine interactions with age and gender. RESULTS: Overall, we observed predominantly left amygdala and substantia innominata activity during the presentation of nonmasked fearful faces relative to fixation, and a decrease in activation in these regions with repeated exposure to the faces. Adults showed increased left amygdala activity for fearful faces relative to neutral faces. This pattern was not observed in the children who showed greater amygdala activity with neutral faces than with fearful faces. For the children, there was an interaction of gender and condition whereby boys but not girls showed less activity with repeated exposure to the fearful faces. CONCLUSIONS: This is the first study to examine developmental differences in the amygdala response to facial expressions using functional magnetic resonance imaging.

Adult↗

PubMed2001

Amygdala response to fearful faces in anxious and depressed children.

BACKGROUND: Alterations in amygdala function have been implicated in the pathophysiological characteristics of adult anxiety and depressive disorders. Studies with healthy adults and children, as well as with adults who have amygdala lesions, have found facial expressions of emotion to be useful probes of amygdala activity. Our study examined the amygdala response to fearful and neutral facial expressions in healthy, anxious, and depressed children. We hypothesized that children with anxiety and depression may show atypical amygdala responses to emotional stimuli. METHODS: Twelve children (8-16 years of age) with generalized anxiety or panic disorder and 12 healthy comparison children underwent noninvasive functional magnetic resonance imaging while viewing photographs of fearful and neutral facial expressions. In a second comparison, 5 girls with major depressive disorder were compared with 5 anxious and 5 healthy girls from the previous sample. RESULTS: Children with anxiety disorders showed an exaggerated amygdala response to fearful faces compared with healthy children, whereas depressed children showed a blunted amygdala response to these faces. In addition, the magnitude of the amygdala's signal change between fearful and neutral faces was positively correlated with the severity of everyday anxiety symptoms. CONCLUSIONS: Our results suggest that amygdala function is affected in both anxiety and depression during childhood and adolescence. Moreover, this disruption appears to be specific to the child's own rating of everyday anxiety.

Adolescent↗

PubMed2001

Efficacy of paroxetine in the treatment of adolescent major depression: a randomized, controlled trial.

OBJECTIVE: To compare paroxetine with placebo and imipramine with placebo for the treatment of adolescent depression. METHOD: After a 7- to 14-day screening period, 275 adolescents with major depression began 8 weeks of double-blind paroxetine (20-40 mg), imipramine (gradual upward titration to 200-300 mg), or placebo. The two primary outcome measures were endpoint response (Hamilton Rating Scale for Depression [HAM-D] score < or = 8 or > or = 50% reduction in baseline HAM-D) and change from baseline HAM-D score. Other depression-related variables were (1) HAM-D depressed mood item; (2) depression item of the Schedule for Affective Disorders and Schizophrenia for Adolescents-Lifetime version (K-SADS-L); (3) Clinical Global Impression (CGI) improvement scores of 1 or 2; (4) nine-item depression subscale of K-SADS-L; and (5) mean CGI improvement scores. RESULTS: Paroxetine demonstrated significantly greater improvement compared with placebo in HAM-D total score < or = 8, HAM-D depressed mood item, K-SADS-L depressed mood item, and CGI score of 1 or 2. The response to imipramine was not significantly different from placebo for any measure. Neither paroxetine nor imipramine differed significantly from placebo on parent- or self-rating measures. Withdrawal rates for adverse effects were 9.7% and 6.9% for paroxetine and placebo, respectively. Of 31.5% of subjects stopping imipramine therapy because of adverse effects, nearly one third did so because of adverse cardiovascular effects. CONCLUSIONS: Paroxetine is generally well tolerated and effective for major depression in adolescents.

Adolescent↗

PubMed2000

Low growth hormone response to growth hormone-releasing hormone in child depression.

BACKGROUND: This study examined growth hormone (GH) response to growth hormone-releasing hormone (GHRH) in a large sample of depressed children compared with normal control children. Within-subject comparisons were also performed in control subjects to examine test-retest reliability and in depressed children comparing episode versus clinical recovery. METHODS: The sample included depressed children (n = 82) and normal control children (n = 55) group-matched for age, gender, and pubertal status; the mean ages were 11.2 +/- 1.7 and 11.2 +/- 1.8 years, respectively. We gave GHRH (0.1 mcg/Kg) at 9 AM, and serum GH levels were determined every 15 min from -30 min through +90 min of the GHRH infusion. A subgroup of normal control subjects (n = 11) repeated the protocol for test-retest reliability within a 2-month interval. A subgroup of depressed children (n = 20) were restudied off all medications following full clinical remission from depression. RESULTS: The mean GH response to GHRH was significantly lower in the depressed group (8.7 ng/mL +/- SEM 0.9) compared with normal control children [12.2 ng/mL +/- SEM 1.3; t(135) = 2.59, p =.01 effect size 0.44]. The test-retest reliability of GH response to GHRH was stable (intraclass correlation =.93 for mean post-GH). The GH response to GHRH remained low in subjects restudied during clinical remission from depression. CONCLUSIONS: Depressed children show low GH response to GHRH. The measure appears to be reliable, and the low GH response continues following clinical remission. Further studies are needed to explore the mechanism and relative specificity of this finding.

Child↗

PubMed2000

A pilot study of amygdala volumes in pediatric generalized anxiety disorder.

BACKGROUND: The neurodevelopment of childhood anxiety disorders is not well understood. Basic research has implicated the amygdala and circuits related to these nuclei as being central to several aspects of fear and fear-related behaviors in animals. METHODS: Magnetic resonance imaging was used to measure amygdala volumes and comparison brain regions in 12 child and adolescent subjects with generalized anxiety disorder and 24 comparison subjects. Groups were matched on age, sex, height, and handedness and were also similar on measures of weight, socioeconomic status, and full scale IQ. RESULTS: Right and total amygdala volumes were significantly larger in generalized anxiety disorder subjects. Intracranial, cerebral, cerebral gray and white matter, temporal lobe, hippocampal, and basal ganglia volumes and measures of the midsagittal area of the corpus callosum did not differ between groups. CONCLUSIONS: Although these data are preliminary and from a small sample, the results are consistent with a line of thinking that alterations in the structure and function of the amygdala may be associated with pediatric generalized anxiety disorder.

Adolescent↗

PubMed2000

Nocturnal growth hormone secretion studies in adolescents with or without major depression re-examined: integration of adult clinical follow-up data.

BACKGROUND: Early sleep is associated with an increased secretion of human growth hormone (GH) through muscarinic inhibition of somatostatin, a GH suppressant. A clinical follow-up was performed approximately 1 decade after depressed and psychiatrically "normal" control adolescents, who were now young adults, had undergone baseline serial GH measurements over a 24-hour period on the third night of sleep polysomnography studies. METHODS: The study population consisted of 77 young adults who had received a diagnosis of adolescent major depressive disorder and had participated in the adolescent sleep and neuroendocrine studies. Alternatively, the young adult subjects were assessed as normal adolescent control subjects free of any psychiatric diagnosis. Blood samples had been collected for GH every 20 min during the 24-hour period coinciding with the third consecutive night of sleep electroencephalography. Subjects, now in young adulthood, were relocated and blindly reinterviewed using the Schedule for Affective Disorders and Schizophrenia (lifetime version). The original adolescent nocturnal GH data were analyzed in light of the information obtained regarding clinical course into adulthood. RESULTS: A substantial proportion of the nominally normal control group developed at least one episode of major depression or dysthymia during the follow-up period. "Latent" depressive subjects differed from depression-free control subjects by having exhibited a significantly more rapid increase of adolescent nocturnal GH secretion following sleep onset. Of the subjects who had experienced at least one lifetime major depressive episode during the follow-up, the subgroup who would go on to make suicide attempts secreted significantly greater amounts of GH during the first 4 hours of sleep. Adults with lifetime depression exhibited significantly reduced levels of GH in the 100 min preceding sleep onset during adolescence. CONCLUSIONS: Assignment of subjects based on longitudinal clinical follow-up into adulthood revealed that the sleep-related GH secretion paradigm has predictive value for future depressive episodes and future suicide attempts. Dysfunction of complex sleep-onset mechanisms may be a premorbid marker of depression and suicidal behavior.

Adolescent↗

PubMed2000

Growth hormone secretion in children and adolescents at high risk for major depressive disorder.

BACKGROUND: Decreased growth hormone (GH) response to pharmacologic stimulation has been found in children and adolescents during an episode of major depressive disorder and after recovery. In this study, we sought to determine whether GH secretion is similarly altered in children and adolescents who had never experienced depression but were at high risk of developing depression. METHODS: Subjects were 8 through 16 years of age and selected for high- and low-risk status according to familial loading for mood disorders. Sixty-four high-risk and 55 low-risk healthy subjects participated in the study, which assessed the following GH measures: (1) GH before growth hormone-releasing hormone (GHRH) infusion, every 15 minutes for 30 minutes; (2) GH response after intravenous infusion of GHRH (0.1 microg/kg), every 15 minutes for 90 minutes; and (3) nocturnal GH every 20 minutes from 9 PM until morning awakening. RESULTS: After stimulation with GHRH, the high-risk subjects secreted significantly less GH compared with the low-risk healthy controls (effect sizes for mean and peak GH, 0.52 [P =.007] and 0.40 [P =.04], respectively). In contrast, there were no between-group differences in the pre-GHRH and nocturnal GH secretion levels. Exposure to recent stressors was not associated with GH secretion. CONCLUSIONS: Taken together with previous evidence of decreased GH after GHRH infusion in acutely depressed and recovered children, these results indicate that the decreased GH response found in high-risk subjects may represent a trait marker for depression in children and adolescents.

Adolescent↗

PubMed2000

Psychosis in a pediatric mood and anxiety disorders clinic: phenomenology and correlates.

OBJECTIVES: To examine the demographics and phenomenology of psychosis in a sample of children and adolescents referred to a mood and anxiety disorders clinic. METHOD: Patients (N = 2,031) were assessed with the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present Episode version and classified as definite, probable, or nonpsychotic. Clinical and demographic characteristics of the groups were compared,and symptoms of psychosis were analyzed using factor analysis. RESULTS: Definite psychotic symptoms were seen in approximately 90 (4.5%) patients: 80% of these reported hallucinations (mainly auditory), 22% delusions, and 3.3% thought disorder. Of the patients with definite psychotic symptoms, 24% had bipolar disorder, 41% had major depression, 21% had subsyndromal depression, and 14% had schizophrenia spectrum disorders (schizophrenia and schizoaffective disorders). Factor analysis of the definite psychotic symptoms yielded 4 factors: hallucinations, thought disorder, delusions, and manic thought disorder. Psychotic patients had a higher frequency of comorbid disorders and suicidal ideation than nonpsychotic patients. CONCLUSIONS: Outpatient youngsters with mood disorders frequently present with psychotic symptoms, in particular auditory hallucinations. These patients commonly have comorbid psychiatric disorders and suicidal ideation.

Adolescent↗

PubMed2000

K-SADS-PL.

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Attention Deficit Disorder with Hyperactivity↗

PubMed2000

Atypical symptoms of depression in a sample of depressed child and adolescent outpatients.

OBJECTIVE: To examine the presence of symptoms of atypical depression among children and adolescents with a major depressive disorder (MDD). METHOD: One thousand forty-six youths (aged 6-19 years) meeting DSM-III-R criteria for MDD were included in the study. All subjects had presented at an outpatient clinic seeking treatment and were identified as having MDD via clinical interviews using the semistructured Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present Episode (K-SADS-P) with the youngster themselves and a parent/guardian. A diagnosis of atypical depression was derived from the symptoms of depression assessed in the K-SADS-P and required the presence of mood reactivity and at least one the following symptoms: hypersomnia, increased appetite, weight gain, or psychomotor retardation (substituted for leaden paralysis). RESULTS: One hundred sixty-two (15.5%) of the depressed youths met criteria for atypical depression. The symptoms of atypical depression were found to correlate marginally, and the diagnosis of atypical depression had marginal construct validity for both children and adolescents. CONCLUSIONS: The findings from this large sample of depressed children and adolescents suggest that atypical features of depression occur in this age group. However, the diagnosis of atypical depression appears to have only marginal construct validity for both children and adolescents.

Adolescent↗

PubMed2000

Parent-child bonding and family functioning in depressed children and children at high risk and low risk for future depression.

OBJECTIVE: To evaluate parent-child bonding and familial functioning in depressed children, children at high risk for depression, and low-risk controls. METHOD: Diagnoses of children and their relatives were obtained via structured interviews with all available informants. Depressed children (n = 54) received a diagnosis of current major depressive disorder (MDD). The high-risk children (n = 21) had no lifetime diagnoses of mood disorders, but at least one first-degree relative with a lifetime history of depression. The low-risk controls (n = 23) had no lifetime psychiatric disorders and no first-degree relative with a lifetime history of mood disorders. Parent-child bonding was evaluated with the child's report on the Parental Bonding Instrument (PBI). Familial functioning was evaluated with each parent answering the Family Assessment Device (FAD). RESULTS: Significant differences were found between the MDD and low-risk children on most parameters of the PBI and FAD. The children with MDD reported significantly elevated maternal overprotection, and their fathers scored significantly lower on the FAD scales of Behavioral Control and General Functioning, compared with the high-risk children. Mothers of high-risk children had significantly lower scores on the Roles and Affective Involvement dimensions of the FAD compared with mothers of low-risk children. Current maternal depression had a deleterious effect on the child's perception of maternal protection and paternal care, mother's report on all FAD scales, and father's report on most FAD scales, whether interacting with the child's depression or existing even if the child was not depressed. CONCLUSION: Maternal depression and its interaction with the child's depression appear to have negative consequences for parent-child bonding and family functioning.

Adolescent↗

PubMed1999

Prolactin secretion in depressed children.

BACKGROUND: Few studies have examined the involvement of the central dopaminergic system in the pathophysiology of mood disorders. The study of prolactin (PRL) secretion may be an informative indirect method for the assessment of the dopaminergic system in children with major depressive disorder (MDD). METHODS: Plasma PRL concentrations were measured at 20-min intervals over a 24-hr period in 40 pre-pubertal children with MDD, 18 with non-affective psychiatric disorders (PC), and 6 normal controls (NC). A subgroup of depressed children (n = 21) was restudied after recovery. RESULTS: There was no significant differences in either the amount or the pattern of PRL secretion between the MDD, PC, and NC groups. Children who recovered from their depression secreted less PRL during sleep and more while awake compared to when they were acutely depressed. CONCLUSIONS: Overall, there were no differences in baseline PRL secretion between children with MDD, NC and psychiatric control. These results suggest that the dopaminergic system as measured by baseline PRL blood levels is not compromised in children with MDD.

Anxiety Disorders↗

PubMed1999

A.E. Bennett Research Award. Developmental traumatology. Part I: Biological stress systems.

BACKGROUND: This investigation examined the relationship between trauma, psychiatric symptoms and urinary free cortisol (UFC) and catecholamine (epinephrine [EPI], norepinephrine [NE], dopamine [DA]) excretion in prepubertal children with posttraumatic stress disorder (PTSD) secondary to past child maltreatment experiences (n = 18), compared to non-traumatized children with overanxious disorder (OAD) (n = 10) and healthy controls (n = 24). METHODS: Subjects underwent comprehensive psychiatric and clinical assessments and 24 hour urine collection for measurements of UFC and urinary catecholamine excretion. Biological and clinical measures were compared using analyses of variance. RESULTS: Maltreated subjects with PTSD excreted significantly greater concentrations of urinary DA and NE over 24 hours than OAD and control subjects and greater concentrations of 24 hour UFC than control subjects. Post hoc analysis revealed that maltreated subjects with PTSD excreted significantly greater concentrations of urinary EPI than OAD subjects. Childhood PTSD was associated with greater co-morbid psychopathology including depressive and dissociative symptoms, lower global assessment of functioning, and increased incidents of lifetime suicidal ideation and attempts. Urinary catecholamine and UFC concentrations showed positive correlations with duration of the PTSD trauma and severity of PTSD symptoms. CONCLUSIONS: These data suggest that maltreatment experiences are associated with alterations of biological stress systems in maltreated children with PTSD. An improved psychobiological understanding of trauma in childhood may eventually lead to better treatments of childhood PTSD.

Adolescent↗

PubMed1999

A.E. Bennett Research Award. Developmental traumatology. Part II: Brain development.

BACKGROUND: Previous investigations suggest that maltreated children with a diagnosis of posttraumatic stress disorder (PTSD) evidence alterations of biological stress systems. Increased levels of catecholaminergic neurotransmitters and steroid hormones during traumatic experiences in childhood could conceivably adversely affect brain development. METHODS: In this study, 44 maltreated children and adolescents with PTSD and 61 matched controls underwent comprehensive psychiatric and neuropsychological assessments and an anatomical magnetic resonance imaging (MRI) brain scan. RESULTS: PTSD subjects had smaller intracranial and cerebral volumes than matched controls. The total midsagittal area of corpus callosum and middle and posterior regions remained smaller; while right, left, and total lateral ventricles were proportionally larger than controls, after adjustment for intracranial volume. Brain volume robustly and positively correlated with age of onset of PTSD trauma and negatively correlated with duration of abuse. Symptoms of intrusive thoughts, avoidance, hyperarousal or dissociation correlated positively with ventricular volume, and negatively with brain volume and total corpus callosum and regional measures. Significant gender by diagnosis effect revealed greater corpus callosum area reduction in maltreated males with PTSD and a trend for greater cerebral volume reduction than maltreated females with PTSD. The predicted decrease in hippocampal volume seen in adult PTSD was not seen in these subjects. CONCLUSIONS: These data suggest that the overwhelming stress of maltreatment experiences in childhood is associated with adverse brain development.

Adolescent↗

PubMed1999

Depressed adolescents grown up.

CONTEXT: Major depressive disorder (MDD) that arises in adolescence impairs functioning and is associated with suicide risk, but little is known about its continuity into adulthood. OBJECTIVE: To describe the clinical course of adolescent-onset MDD into adulthood. DESIGN AND PARTICIPANTS: Prospective case-control study. Seventy-three subjects had onset of MDD based on systematic clinical assessment during adolescence (Tanner stage III-V) and 37 controls had no evidence of past or current psychiatric disorders, and also were assessed in adolescence (assessment years: 1977-1985). Follow-up was conducted 10 to 15 years after the initial assessment by an independent team without knowledge of initial diagnosis (follow-up years: 1992-1996). SETTING: Cases were identified at Columbia Presbyterian Hospital, New York City, NY; controls were recruited from the community. MAIN OUTCOME MEASURES: Suicide and suicide attempts, psychiatric diagnoses, treatment utilization, and social functioning. RESULTS: Clinical outcomes of adolescent-onset MDD into adulthood compared with control subjects without psychiatric illness include a high rate of suicide (7.7%); a 5-fold increased risk for first suicide attempt; a 2-fold increased risk of MDD, but not other psychiatric disorders; an increased occurrence of psychiatric and medical hospitalization; and impaired functioning in work, social, and family life. Thirty-seven percent of those with adolescent MDD survived without an episode of MDD in adulthood vs 69% of the control participants (relative risk, 2.2 [95% confidence interval, 1.0-4.7; P<.05]). CONCLUSION: There is substantial continuity, specificity, morbidity, and potential mortality from suicide into adulthood in adolescent-onset MDD patients. Now that empirically based guides to their treatment are becoming available, early identification and treatment seems warranted.

Adolescent↗