Imipramine in prepubertal major depressive disorders.

Area of Science:

• Child and Adolescent Psychiatry
• Clinical Pharmacology
• Neuroscience

Background:

• Major depressive disorder (MDD) in prepubertal children is a significant concern.
• Imipramine hydrochloride is a tricyclic antidepressant with potential efficacy in pediatric depression.
• Optimal dosing strategies for imipramine in this population remain under investigation.

Purpose of the Study:

• To evaluate the effectiveness of imipramine hydrochloride in prepubertal children with MDD.
• To explore the relationship between plasma levels of imipramine and its metabolite, desipramine, and clinical response.
• To identify predictors of treatment response in this patient group.

Main Methods:

• A five-week, double-blind, placebo-controlled study (N=38) and a plasma level/clinical response study (N=30) were conducted.
• Children were diagnosed with MDD using the Schedule for Affective Disorders and Schizophrenia for School Age Children.
• Response rates and the correlation between plasma drug levels and symptom improvement were analyzed.

Main Results:

• Response rates in the double-blind study were similar between imipramine (56%) and placebo (68%).
• Higher maintenance plasma levels of imipramine plus desipramine linearly predicted clinical response (P < .003).
• Weight-corrected dosage did not predict response; depressive hallucinations negatively predicted response.

Conclusions:

• The mean imipramine dosage used in the study was likely too low for efficacy.
• Future studies should incorporate plasma level monitoring and titration to target levels (above 150 ng/mL).
• A placebo washout period may be beneficial in designing future trials for prepubertal MDD.