Evidence for Increased Glutamatergic Cortical Facilitation in Children and Adolescents With Major Depressive Disorder Glutamatergic Cortical Facilitation and MDD

Croarkin PE, Nakonezny PA, Husain MM, et al. — Fri, 01 Mar 2013 00:00:00 GMT

Context

Converging lines of evidence implicate the glutamate and γ-aminobutyric acid neurotransmitter systems in the pathophysiology of major depressive disorder. Transcranial magnetic stimulation cortical excitability and inhibition paradigms have been used to assess cortical glutamatergic and γ-aminobutyric acid–mediated tone in adults with major depressive disorder, but not in children and adolescents.

Objective

To compare measures of cortical excitability and inhibition with 4 different paradigms in a group of children and adolescents with major depressive disorder vs healthy controls.

Design

Cross-sectional study examining medication-free children and adolescents (aged 9-17 years) with major depressive disorder compared with healthy controls. Cortical excitability was assessed with motor threshold and intracortical facilitation measures. Cortical inhibition was measured with cortical silent period and intracortical inhibition paradigms.

Setting

University-based child and adolescent psychiatry clinic and neurostimulation laboratory.

Patients

Twenty-four participants with major depressive disorder and 22 healthy controls matched for age and sex. Patients with major depressive disorder were medication naive and had moderate to severe symptoms based on an evaluation with a child and adolescent psychiatrist and scores on the Children's Depression Rating Scale–Revised.

Main Outcome Measures

Motor threshold, intracortical facilitation, cortical silent period, and intracortical inhibition.

Results

Compared with healthy controls, depressed patients had significantly increased intracortical facilitation at interstimulus intervals of 10 and 15 milliseconds bilaterally. There were no significant group differences in cortical inhibition measures.

Conclusions

These findings suggest that major depressive disorder in children and adolescents is associated with increased intracortical facilitation and excessive glutamatergic activity.

Prevalence, Correlates, and Treatment of Lifetime Suicidal Behavior Among Adolescents Results From the National Comorbidity Survey Replication Adolescent Supplement Lifetime Suicidal Behavior Among Adolescents

Nock MK, Green J, Hwang I, et al. — Fri, 01 Mar 2013 00:00:00 GMT

Context

Although suicide is the third leading cause of death among US adolescents, little is known about the prevalence, correlates, or treatment of its immediate precursors, adolescent suicidal behaviors (ie, suicide ideation, plans, and attempts).

Objectives

To estimate the lifetime prevalence of suicidal behaviors among US adolescents and the associations of retrospectively reported, temporally primary DSM-IV disorders with the subsequent onset of suicidal behaviors.

Design

Dual-frame national sample of adolescents from the National Comorbidity Survey Replication Adolescent Supplement.

Setting

Face-to-face household interviews with adolescents and questionnaires for parents.

Participants

A total of 6483 adolescents 13 to 18 years of age and their parents.

Main Outcome Measures

Lifetime suicide ideation, plans, and attempts.

Results

The estimated lifetime prevalences of suicide ideation, plans, and attempts among the respondents are 12.1%, 4.0%, and 4.1%, respectively. The vast majority of adolescents with these behaviors meet lifetime criteria for at least one DSM-IV mental disorder assessed in the survey. Most temporally primary (based on retrospective age-of-onset reports) fear/anger, distress, disruptive behavior, and substance disorders significantly predict elevated odds of subsequent suicidal behaviors in bivariate models. The most consistently significant associations of these disorders are with suicide ideation, although a number of disorders are also predictors of plans and both planned and unplanned attempts among ideators. Most suicidal adolescents (>80%) receive some form of mental health treatment. In most cases (>55%), treatment starts prior to onset of suicidal behaviors but fails to prevent these behaviors from occurring.

Conclusions

Suicidal behaviors are common among US adolescents, with rates that approach those of adults. The vast majority of youth with suicidal behaviors have preexisting mental disorders. The disorders most powerfully predicting ideation, though, are different from those most powerfully predicting conditional transitions from ideation to plans and attempts. These differences suggest that distinct prediction and prevention strategies are needed for ideation, plans among ideators, planned attempts, and unplanned attempts.

JAMA Psychiatry: Adolescent Medicine Topic Collection

Evidence for Increased Glutamatergic Cortical Facilitation in Children and Adolescents With Major Depressive Disorder Glutamatergic Cortical Facilitation and MDD

Prevalence, Correlates, and Treatment of Lifetime Suicidal Behavior Among Adolescents Results From the National Comorbidity Survey Replication Adolescent Supplement Lifetime Suicidal Behavior Among Adolescents