Publication bias and the pharmaceutical industry: the case of lamotrigine in bipolar disorder.

Publication bias, especially the lack of publication of negative treatment studies, is known to be a major problem in the medical literature. In particular, it appears that the pharmaceutical industry is not routinely making data from negative studies available through the published scientific literature. In this paper, we review the case of studies with lamotrigine in bipolar disorder, describing evidence of lack of efficacy in multiple mood states outside of the primary area of efficacy (prophylaxis of mood episodes). In particular, the drug has very limited, if any, efficacy in acute bipolar depression and rapid-cycling bipolar disorder, areas in which practicing clinicians, as well as some academic leaders, have supported its use. The negative unpublished data now made available on lamotrigine provide an important context for clinical practice and research, and also raise important scientific and public policy concerns about having access to studies showing inefficacy with psychotropic medications.

Is adjunctive open-label zonisamide effective for bipolar disorder?

OBJECTIVE: To assess the effectiveness and safety of zonisamide in bipolar disorder. METHODS: A chart review was conducted of naturalistic treatment with zonisamide in 35 outpatients meeting DSM-IV criteria for bipolar disorder (9 males, 26 females; mean +/- SD age = 29.2 +/- 12.7; 14 with bipolar disorder type I, 6 with bipolar disorder type II, and 14 with bipolar disorder not otherwise specified). Patients received zonisamide adjunctive therapy between January 1994 and December 2004. Treatment response was defined as a Clinical Global Impressions - Improvement (CGI-I) scale score of +2 (much improved) or + 3 (very much improved). RESULTS: Zonisamide was moderately to markedly effective in 9 subjects (26%). Indication for treatment included depressive (34.3%, [12/35]), manic/hypomanic (28.6%, [10/35]), or mixed (31.4%, [11/35]) symptoms. The mean zonisamide dose was 130 mg/d for a mean duration of treatment of 27.0 +/- 32.3 weeks. Sedation (25%, [4/16]) was the most common side effect; 19/35 (54.3%) reported no side effects. 17/35 (49%) patients terminated early, mostly due to adverse effects (6/35). Using a multivariable model, predictors of response, concurrent mood stabilizers, dose and bipolar subtype (bipolar type I > type II/NOS), were controlled for in this sample. CONCLUSIONS: In 35 persons with bipolar disorder taking standard mood stabilizers and other psychotropic agents, adjunctive zonisamide appears to have modest benefit in global improvement when added to a pre-existing complex medication regimen in patients with bipolar spectrum disorder. These pilot data support the need for larger studies to test the potential efficacy of zonisamide for treatment in mood disorders.

Long-term lamotrigine plus lithium for bipolar disorder: One year outcome.

OBJECTIVE: To obtain pilot data in an observational setting on the use of lamotrigine plus lithium in the long-term treatment of patients with bipolar disorder, 87% of whom had failed to respond to at least one previous mood stabilizer. METHODS: Charts of 21 patients (11 females, 10 males, mean age 43.2 years) treated with the combination of lithium and lamotrigine were reviewed retrospectively for treatment response using the Clinical Global Impression-Bipolar Disorder-Improvement scale, divided into benefit for acute depressive symptoms, acute manic symptoms, and overall illness (including prophylaxis of mood episodes). Of the 21 patients, 76% were diagnosed with bipolar I disorder, and depressive symptoms were the most common acute indication for treatment (52%). Mean doses of lithium and lamotrigine were 963 mg/day and 179 mg/day, respectively, used for a mean of 55.7 weeks. RESULTS: Acute antidepressant benefit was observed in 48% of patients, acute anti-manic benefit in 14%, and overall prophylactic benefit in 29%. Side effects were observed in 38%, with cognitive problems most common (29%). 48% discontinued combination therapy, mainly due to lack of efficacy (19%) or activation of manic-like symptoms (19%). CONCLUSIONS: Among a group of largely treatment-resistant bipolar patients, the combination of lithium and lamotrigine appeared effective for acute depressive symptoms in about half of the patients, but acute anti-manic and long-term prophylactic efficacy appeared less robust.

Side effects of atypical antipsychotics: extrapyramidal symptoms and the metabolic syndrome.

In this article we examine the two major classes of side effects with atypical antipsychotics: extrapyramidal symptoms (EPS) and the metabolic syndrome (the triad of diabetes, dyslipidemia, and hypertension, with associated obesity). We conclude that atypical antipsychotics continue to have notable risks of EPS, particularly akathisia, and that these agents also appear to increase the risk of the metabolic syndrome, though this effect seems most marked with clozapine and olanzapine. Novel conclusions based on this review are as follows: we provide a classification scheme based on low versus high D2 binding affinity (which is, to our knowledge, a new means of classifying atypical antipsychotics); we emphasize that the akathisia risk is likely equal among agents and that tardive dyskinesia is an early, and not late, risk in treatment (a common misconception); we make the methodological point that in randomized clinical trials, there is a high risk of false-negatives regarding side effects; we raise the issue of confounding bias in epidemiological studies of metabolic syndrome; and we stress the need to compare side effects in the same studies and not different studies. Future prospective observational cohort studies must target side effects and be designed to collect and analyze data on confounding factors.