Arif O. Khan

Severity of depression and response to antidepressants and placebo: An analysis of the food and Drug Administration database

Some studies suggest that more severely ill patients with depression respond well to antidepressants and poorly to placebo, whereas those who are mildly ill respond equally well to antidepressants and placebo. This notion has implications for the design of clinical trials. To further assess and substantiate these putative predictors of antidepressant and placebo response, we assessed the Food and Drug Administration database of 45 phase II and III antidepressant clinical trials. The frequency of statistically significant differences between antidepressants and placebo was higher in the trials that included patients with more severe depression. In the antidepressant-treated groups, the magnitude of symptom reduction was signif-icantly related to mean initial Hamilton Rating Scale for Depression (HAM-D) score; the higher the mean initial HAM-D score, the larger the change. With placebo treatment, however, the higher the mean initial HAM-D score, the smaller the change. Early discontinuation was more frequent among patients whose mean initial HAM-D scores were higher. These data may help inform the design of future antidepressant clinical trials.

Seizure incidence in psychopharmacological clinical trials: an analysis of Food and Drug Administration (FDA) summary basis of approval reports.

BACKGROUND Clinical trial data provide an approach to the investigation of the effects of psychopharmacological agents, and psychiatric disorders themselves, on seizure threshold. METHODS We accessed public domain data from Food and Drug Administration (FDA) Phase II and III clinical trials as Summary Basis of Approval (SBA) reports that noted seizure incidence in trials of psychotropic drugs approved in the United States between 1985 and 2004, involving a total of 75,873 patients. We compared seizure incidence among active drug and placebo groups in psychopharmacological clinical trials and the published rates of unprovoked seizures in the general population. RESULTS Increased seizure incidence was observed with antipsychotics that was accounted for by clozapine and olanzapine, and with drugs indicated for the treatment of OCD that was accounted for by clomipramine. Alprazolam, bupropion immediate release (IR) form, and quetiapine were also associated with higher seizure incidence. The incidence of seizures was significantly lower among patients assigned to antidepressants compared to placebo (standardized incidence ratio = .48; 95% CI, .36- .61). In patients assigned to placebo, seizure incidence was greater than the published incidence of unprovoked seizures in community nonpatient samples. CONCLUSIONS Proconvulsant effects are associated with a subgroup of psychotropic drugs. Second-generation antidepressants other than bupropion have an apparent anticonvulsant effect. Depression, psychotic disorders, and OCD are associated with reduced seizure threshold.

A placebo-controlled trial of lamotrigine for painful HIV-associated neuropathy

Objective: To investigate the analgesic efficacy of lamotrigine in the treatment of painful HIV-associated distal sensory polyneuropathy (DSP). Background: The pathogenesis of HIV-associated DSP is unknown and there is no effective treatment. A novel anticonvulsant, lamotrigine, blocks voltage-sensitive sodium channels and inhibits the release of glutamate and aspartate. There have been anecdotal reports of efficacy of lamotrigine in the treatment of painful neuropathy and trigeminal neuralgia. Methods: In a multicenter, randomized, double-blind, placebo-controlled study, lamotrigine was initiated at 25 mg per day and slowly titrated over 7 weeks to 300 mg per day. Study duration was 14 weeks. The primary outcome measure was change in pain on the modified Gracely scale with secondary outcome measures including change in neurologic examination, use of concomitant analgesic medications, and global pain relief. Results: Of 42 enrolled subjects, 13 did not complete the 14-week study endpoint. In five of these, rash was the cause for dropout. In the remaining 29 evaluable subjects, 20 patients received placebo and 9 received lamotrigine. The pain scores at baseline were not significantly different. The reduction in average pain from baseline to week 14 was greater (p = 0.03) in the lamotrigine group (−0.55) than in the placebo group (−0.18), adjusting for baseline levels of pain. There was no difference between the groups on the change in peak worst pain. Conclusions: In this small trial, lamotrigine showed promise in the treatment of pain associated with HIV-related DSP. The frequency of rash was greater than in lamotrigine studies in epilepsy. A larger controlled study of lamotrigine is warranted.

Aripiprazole monotherapy in nonpsychotic bipolar I depression: results of 2 randomized, placebo-controlled studies.

Although most treatment research on bipolar disorder has focused on mania, depressive episodes occur more frequently among patients with bipolar disorder. Here, we report the results of 2 identically designed, 8-week, multicenter, randomized, double-blind, placebo-controlled studies (CN138-096 and CN138-146) to evaluate the efficacy and safety of aripiprazole monotherapy in outpatients with bipolar I disorder experiencing a major depressive episode without psychotic features. Patients were randomized to placebo or aripiprazole (initiated at 10 mg/d, then flexibly dosed at 5-30 mg/d based on clinical effect and tolerability). The primary end point was mean change from baseline to Week 8 (last observation carried forward) in the Montgomery-Åsberg Depression Rating Scale total score. In Studies 1 and 2, respectively, 186 and 187 patients were randomized to aripiprazole, and 188 and 188 to placebo. Although statistically significant differences were observed during Weeks 1 to 6, aripiprazole did not achieve statistical significance versus placebo at Week 8 in either study in the change in Montgomery-Åsberg Depression Rating Scale total (primary end point). In addition, despite early statistical separation on the Clinical Global Impressions Bipolar Version Severity of Illness-Depression score (key secondary end point), aripiprazole was not superior to placebo at end point. Aripiprazole was associated with a higher incidence of akathisia, insomnia, nausea, fatigue, restlessness, and dry mouth versus placebo. More patients discontinued with aripiprazole versus placebo in Study 1 (46.8% vs 35.1%) and Study 2 (41.2% vs 29.8%). Aripiprazole monotherapy-as dosed in this study design-was not significantly more effective than placebo in the treatment of bipolar depression at end point (Week 8).

Frequency of Positive Studies Among Fixed and Flexible Dose Antidepressant Clinical Trials: An Analysis of the Food and Drug Administraton Summary Basis of Approval Reports

The assumption that the design of an antidepressant clinical trial affects the outcome of that trial is based on sparse data. We sought to examine if the dosing schedule, either a fixed dose or a flexible dose type, in an antidepressant clinical trial affects the frequency with which antidepressants show statistical superiority over placebo. Randomized, placebo-controlled clinical trials of nine antidepressants approved by the Food and Drug Administration between 1985 and 2000 were reviewed. These trials comprised 9313 depressed patients who participated in 51 antidepressant clinical trials consisting of 92 treatment arms with eventual approved doses. In the flexible dose trials, 59.6% (34/57) of the antidepressant treatment arms were statistically significant compared to placebo, whereas in the fixed dose trials only 31.4% (11/35) of the antidepressant treatment arms were statistically significant compared to placebo (χ2=6.9, df=1, p<0.01). These data suggest that the antidepressant dose schedule may influence trial outcome due in part to a significantly lower magnitude of symptom reduction with placebo in flexible dose trials (F=4.08, df=1, 48, p<0.05) compared to fixed dose trials. Symptom reduction was similar with antidepressants in the flexible and fixed dose trials. Further, the primary function of finding a dose–response relationship was not found among the fixed dose studies.

Sex differences in antidepressant response in recent antidepressant clinical trials

Abstract: Some previous reports suggest that women respond differently than men to antidepressant treatment. Much of this literature compares men and womens response to tricyclics to that of newer antidepressants (SSRIs, SNRI), or only examines one particular antidepressant. This study compares men and womens responses to 6 newer antidepressants. A total of 15 randomized, placebo-controlled trials that included 323 depressed patients were examined for sex differences in antidepressant treatment response. Women had a significantly greater response than men to SSRI antidepressants. A similar trend was seen for those assigned to an SNRI antidepressant, although not to the same extent as with SSRI antidepressants. Although these gender differences in treatment response are not large enough to suggest that gender should guide the clinical use of SSRI and SNRI antidepressants, the results do have implications for the design and interpretation of antidepressant clinical trials. These findings also raise the possibility that antidepressants may work somewhat differently in men and women.

Autozygome-guided exome sequencing in retinal dystrophy patients reveals pathogenetic mutations and novel candidate disease genes

Retinal dystrophy (RD) is a heterogeneous group of hereditary diseases caused by loss of photoreceptor function and contributes significantly to the etiology of blindness globally but especially in the industrialized world. The extreme locus and allelic heterogeneity of these disorders poses a major diagnostic challenge and often impedes the ability to provide a molecular diagnosis that can inform counseling and gene-specific treatment strategies. In a large cohort of nearly 150 RD families, we used genomic approaches in the form of autozygome-guided mutation analysis and exome sequencing to identify the likely causative genetic lesion in the majority of cases. Additionally, our study revealed six novel candidate disease genes (C21orf2, EMC1, KIAA1549, GPR125, ACBD5, and DTHD1), two of which (ACBD5 and DTHD1) were observed in the context of syndromic forms of RD that are described for the first time.

A Systematic Review of Comparative Efficacy of Treatments and Controls for Depression

Background Although previous meta-analyses have examined effects of antidepressants, psychotherapy, and alternative therapies for depression, the efficacy of these treatments alone and in combination has not been systematically compared. We hypothesized that the differences between approved depression treatments and controls would be small. Methods and Findings The authors first reviewed data from Food and Drug Administration Summary Basis of Approval reports of 62 pivotal antidepressant trials consisting of data from 13,802 depressed patients. This was followed by a systematic review of data from 115 published trials evaluating efficacy of psychotherapies and alternative therapies for depression. The published depression trials consisted of 10,310 depressed patients. We assessed the percentage symptom reduction experienced by the patients based on treatment assignment. Overall, antidepressants led to greater symptom reduction compared to placebo among both unpublished FDA data and published trials (F = 38.5, df = 239, p<0.001). In the published trials we noted that the magnitude of symptom reduction with active depression treatments compared to controls was significantly larger when raters evaluating treatment effects were un-blinded compared to the trials with blinded raters (F = 2.17, df = 313, p<0.05). In the blinded trials, the combination of antidepressants and psychotherapy provided a slight advantage over antidepressants (p = 0.027) and psychotherapy (p = 0.022) alone. The magnitude of symptom reduction was greater with psychotherapies compared to placebo (p = 0.019), treatment-as-usual (p = 0.012) and waiting-list (p<0.001). Differences were not seen with psychotherapy compared to antidepressants, alternative therapies or active intervention controls. Conclusions In conclusion, the combination of psychotherapy and antidepressants for depression may provide a slight advantage whereas antidepressants alone and psychotherapy alone are not significantly different from alternative therapies or active intervention controls. These data suggest that type of treatment offered is less important than getting depressed patients involved in an active therapeutic program. Future research should consider whether certain patient profiles might justify a specific treatment modality.

Placebo Response and Antidepressant Clinical Trial Outcome

Placebo response magnitude is suspected to affect the outcome of antidepressant clinical trials. To evaluate this, 52 randomized, double-blind, placebo-controlled clinical trials obtained from the FDA were examined to correlate placebo response magnitude with trial outcome. The magnitude of symptom reduction, percentage mean change from baseline in the Hamilton Depression Rating Scale (HAM-D), was assessed for patients assigned to placebo or an antidepressant. Correlation coefficients between symptom reduction with placebo and antidepressants and between symptom reduction with placebo and magnitude of advantage of antidepressants over placebo were assessed. A statistically significant positive correlation was seen between placebo and antidepressant response magnitude (r = .40, p < .001) and between placebo response magnitude and the advantage of antidepressants over placebo (r = −.592, p < .0001). Only 21.1% of antidepressant treatment arms in trials with high placebo response (>30% mean change from baseline) showed statistical superiority over placebo compared with 74.2% in trials with a low placebo response (≤30). Response magnitude varies and has an important effect on antidepressant clinical trials, illustrating the need for a placebo arm to determine if the trial was sensitive to treatment differences and highlighting the dangers of cross-study comparisons.

Mifepristone versus Placebo in the Treatment of Psychosis in Patients with Psychotic Major Depression

BACKGROUND Abnormalities in the hypothalamic pituitary adrenal axis have been implicated in the pathophysiology of psychotic major depression (PMD). Recent studies have suggested that the antiglucocorticoid, mifepristone might have a role in the treatment of PMD. The current study tested the efficacy of mifepristone treatment of the psychotic symptoms of PMD. METHODS 221 patients, aged 19 to 75 years, who met DSM-IV and SCID criteria for PMD and were not receiving antidepressants or antipsychotics, participated in a double blind, randomized, placebo controlled study. Patients were randomly assigned to either 7 days of mifepristone (n = 105) or placebo (n = 116) followed by 21 days of usual treatment. RESULTS Patients treated with mifepristone were significantly more likely to achieve response, defined as a 30% reduction in the Brief Psychiatric Rating Scale (BPRS). In addition, mifepristone treated patients were significantly more likely to achieve a 50% reduction in the BPRS Positive Symptom Scale (PSS). No significant differences were observed on measures of depression. CONCLUSION A seven day course of mifepristone followed by usual treatment appears to be effective and well tolerated in the treatment of psychosis in PMD. This study suggests that the antiglucocorticoid, mifepristone, might represent an alternative to traditional treatments of psychosis in psychotic depression.