Transcranial Magnetic Stimulation Markers of Antidepressant Treatment in Adolescents With Major Depressive Disorder.

BACKGROUND: The goal of this study was to examine baseline transcranial magnetic stimulation measures of cortical inhibition and excitability in depressed patients and characterize their longitudinal posttreatment changes. METHODS: Fifteen adolescents (age 13-17 years) with moderate to severe major depressive disorder and 22 healthy controls (age 9-17) underwent single- and paired-pulse transcranial magnetic stimulation and clinical assessments. Transcranial magnetic stimulation measures included short-interval intracortical inhibition (2 and 4 milliseconds), long-interval intracortical inhibition (100, 150, and 200 milliseconds), cortical silent period, and intracortical facilitation (10, 15, and 20 milliseconds). Ten participants with major depressive disorder initiated antidepressant treatment or had dose adjustments. These participants were reassessed after treatment. Depression symptom severity was measured with the Children's Depression Rating Scale, Revised. Robust regression modeling compared healthy and depressed adolescents at baseline. Relationships between changes in cortical inhibition and changes in depressive symptom severity were assessed in the depressed adolescents receiving antidepressant treatment. RESULTS: Our results revealed that at baseline, short-interval intracortical inhibition-2 was significantly reduced (Padj = .01) in depressed participants, suggesting impaired cortical inhibition compared with healthy controls. At follow-up, improvement in Children's Depression Rating Scale, Revised scores correlated with improvement in short-interval intracortical inhibition-4 amplitude (greater inhibition) after antidepressant treatment (R2 = 0.63; P = .01). CONCLUSIONS: These results suggest that cortical inhibition measures may have promise as biomarkers in adolescents treated for depression.

Psychometric Properties of the Patient Health Questionnaire-9 Modified for Major Depressive Disorder in Adolescents.

OBJECTIVES: The Patient Health Questionnaire-9 Modified (PHQ-9M) is a self-report tool used to assess the presence and severity of depressive symptoms in teenagers. Despite widespread use in primary care clinics and psychiatric settings, the PHQ-9M has not been validated nor are its psychometric properties adequately understood for the adolescent population. This study sought to examine the psychometrics of the PHQ-9M in treatment-seeking, depressed adolescents at a psychiatric psychopharmacology clinic who were concurrently assessed with the Children's Depression Rating Scale Revised (CDRS-R) and Quick Inventory of Depressive Symptomatology-Adolescent (17-item) Self-Report (QIDS-A17-SR). METHODS: Adolescents (N = 160) aged 13 through 18 years with a diagnosis of major depressive disorder, determined on the basis of a clinical interview and semi-structured interview using the Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version, were assessed for severity of depressive symptoms with the PHQ-9M, CDRS-R (adolescent interview only), and QIDS-A17-SR assessments at baseline, 4, and 8 weeks. Classical test theory analysis was used to evaluate the internal consistency and dimensionality of the PHQ-9M. Convergent validity was evaluated via intraclass correlations of the PHQ-9M with the CDRS-R and QIDS-A17-SR. Sensitivity to treatment response was also evaluated. RESULTS: The internal consistency (Cronbach's coefficient α) at baseline, 4, and 8 weeks was 0.879, 0.859, and 0.827 for the PHQ-9M; 0.739, 0.835, and 0.867 for CDRS-R; and 0.712, 0.777, and 0.804 for QIDS-A17-SR, respectively. The PHQ-9M had moderate convergent validity with the CDRS-R but good convergent validity with the QIDS-A17-SR. The PHQ-9M was less sensitive to changes in symptom severity than the CDRS-R and QIDS-A17-SR. CONCLUSIONS: The PHQ-9M appears to be a valid and reliable assessment tool for the severity of depressive symptoms in a psychiatric clinic setting. However, its utility as a treatment outcome measure may be limited compared with other available rating scales.