Lamotrigine in Treatment Resistant Depression in Adolescents

The primary hypothesis of this study is that in fluoxetine (Prozac)-resistant adolescents with Major Depressive Disorder (MDD), Lamotrigine plus fluoxetine will be safe and as effective as sertraline (Zoloft). Our Primary Aim is to determine the efficacy and safety of Lamotrigine-augmentation of fluoxetine for treatment-resistant depression in adolescents. Our Secondary Aims are to characterize the factors associated with treatment-resistance for adolescents with major depression. Also to assess the relationships in the families of adolescents with major depression as they enter treatment, and to track the differences in family relationships for adolescents who respond or do not respond. We postulate that tense, frustrated, irritable, and over-involved relationships constitute a risk factor for attenuated improvement or relapse.

Mood disorders in youth, which include Major Depressive Disorder (MDD) and Bipolar Disorder (BPD), are highly prevalent, and are associated with significant mortality and morbidity. Many youths with major depression fail first-line treatments with psychotherapy and psychotropic medications. Lamotrigine (Lamictal®) recently gained approval by the FDA for maintenance treatment of bipolar disorder in adults. A few pilot studies have also shown promising results for lamotrigine (LTG) in treatment refractory mood disorders in both youth and adults, especially for depressive symptoms (Carandang et al., 2003; Frye et al., 2000). For this proposed study, the modified design begins with adolescents with major depressive disorder who have not responded to a trial of a selective serotonin reuptake inhibitor antidepressant (SSRI), fluoxetine, of adequate dose and duration, and randomizes them either to a second SSRI or to fluoxetine augmented by lamotrigine. Non-responders to 8 weeks of fluoxetine, on at least 40 mg/day, who have not had to discontinue fluoxetine because of adverse effects, would be randomized to: (A) continue fluoxetine with lamotrigine augmentation, for 8 weeks, as in the active arm of the original Stage 2, or (B) discontinue fluoxetine and begin a second SSRI, for 8 weeks. We will use sertraline as the second SSRI, because of the data supporting efficacy from the randomized placebo-controlled trial by Wagner, et.al. (JAMA, '03). Citalopram is also a possibility (Wagner et.al, Am J. Psychiatry '04), but it has been in use for a shorter period of time than sertraline. To maintain the blind, the B group will receive placebo augmentation. The assessments and outcome measures would be the same as in the original study. We will consult with primary care offices to coach them through doing the initial, Stage 1, fluoxetine trial in their offices, and we will monitor the progress of adolescents started on fluoxetine in our clinic. Consent will be discussed only with those who are not responding, and treatment in the study will involve only the post-randomization treatment. Background Mood disorders in youth are common and debilitating. Early-onset of mood disorders often indicates a severe illness, with high likelihood of recurrence into adulthood. For prepubertal children, point prevalence of MDD is 2%, and 6% in adolescents, while the lifetime prevalence for MDD in adolescents is 20% (Birmaher et al., 2002). The duration of a Major Depressive Episode in youth ranges from 3 to 9 months, with 10% lasting more than 2 years, 60-70% recurring in adulthood, and 20-40% developing Bipolar Disorder within 5 years (Weller and Weller, 2000). The prevalence of prepubertal bipolar disorder is estimated at 0.5%. Prevalence of bipolar disorder in adolescents is 1% (Lewinshon et al., 1995). Suicide is the third leading cause of death in the 15 - 24 year old age group (10.1 per 100,000) and the fifth leading cause in the 5 - 14 year old group (0.7 per 100,00), and is highly correlated with MDD and BPD (Pfeffer, 2002). In addition, mood disorders in youth can impair functioning, often characterized by poor school performance, impaired relationships, delinquent behavior, and substance abuse.