Effectiveness of the New Extended-release Formulation of Quetiapine as Monotherapy for the Treatment of Acute Bipolar Depression (Trial D144CC00002)

Comparisons of the tolerability and sensitivity of quetiapine-XR in the acute treatment of schizophrenia, bipolar mania, bipolar depression, major depressive disorder, and generalized anxiety disorder

Quetiapine extended-release (quetiapine-XR) has been studied in patients with schizophrenia, bipolar mania, bipolar depression, major depressive disorder (MDD), and generalized anxiety disorder (GAD). The purpose of this study was to compare the tolerability and sensitivity of quetiapine-XR among these psychiatric conditions. The discontinuation due to adverse events (DAEs) and reported somnolence in randomized, double-blind, placebo-controlled studies of quetiapine-XR in these psychiatric conditions were examined. The absolute risk reduction or increase and the number needed to treat to benefit (NNTB) or harm (NNTH) for DAEs and reported somnolence of quetiapine-XR ≥ 300 mg/d relative to placebo were estimated. Data from one study in schizophrenia (n=465), one in mania (n=316), one in bipolar depression (n=280), two in refractory MDD (n=624), two in MDD (n=669) and three in GAD (n=1109) were available. The risk for DAEs of quetiapine-XR relative to placebo was significantly increased in bipolar depression (NNTH=9), refractory MDD (NNTH=8), MDD (NNTH=9), and GAD (NNTH=5), but not in schizophrenia and mania. The risk for reported somnolence of quetiapine-XR relative to placebo was significantly increased in schizophrenia (600 mg/d NNTH=15 and 800 mg/d NNTH=11), mania (NNTH=8), bipolar depression (NNTH=4), refractory MDD (NNTH=5), MDD (NNTH=5) and GAD (NNTH=5). These results suggest that patients with GAD had the poorest tolerability during treatment with quetiapine-XR, but they had a similar sensitivity as those with bipolar depression and MDD. Patients with schizophrenia or mania had a higher tolerability and a lower sensitivity than those with bipolar depression, MDD, or GAD.

Identification of clinical factors associated with resistance to antidepressants in bipolar depression: results from an European Multicentre Study

This study is the first investigation to identify clinical factors associated with treatment resistance in bipolar depression (TRBD). TRBD is defined as failure to respond to at least two consecutive adequate antidepressant trials. The primary objective of this European Multicenter Study was to identify specific clinical and demographic factors associated with TRBD in a sample of bipolar patients treated for a major depressive episode. A total of 261 bipolar patients with major depressive episode were included in the analysis. Among them, 162 patients were considered as responders to treatment and the remaining 99 patients were considered as treatment resistant with a 17-item Hamilton Rating Scale for Depression Score remaining superior or equal to 17 after two consecutive adequate antidepressant trials. Cox regression analysis was used to examine the association between individual clinical variables and TRBD. We found four clinical variables to be significantly associated with TRBD: melancholia [P=0.01, odds ratio (OR)=2.4], comorbidity with social phobia (P=0.02, OR=2.3), current suicidal risk (P=0.02, OR=1.8) and severe intensity of current depressive episode (P=0.01, OR=1.8). Our findings identify four clinical variables associated with TRBD, which could be further investigated in controlled prospective trials.