Efficacy and Safety of ASP0819 in Patients with Fibromyalgia: Results of a Proof-of-Concept, Randomized, Double-Blind, Placebo-Controlled Trial.

PURPOSE: ASP0819 is a novel, non-opioid KCa3.1 channel opener that reverses abnormal nerve firing of primary sensory afferent nerves. Currently available treatments for fibromyalgia provide only modest relief and are accompanied by a host of adverse side effects. PATIENTS AND METHODS: In this phase 2a, double-blind trial (NCT03056690), adults meeting fibromyalgia diagnostic criteria were randomized 1:1 to receive either 15 mg/day of oral ASP0819 (n=91) or placebo (n=95). The primary endpoint was the change from baseline to Week 8 in the mean daily average pain score. Changes in the Fibromyalgia Impact Questionnaire Revised (FIQR) symptoms, function, and overall impact subscales, as well as changes in the patients' global impression of change, were secondary endpoints; treatment effects on FIQR total score and impact on sleep were exploratory analyses. RESULTS: There was no statistically significant difference between ASP0819 and placebo for the primary endpoint (P=0.086); however, ASP0819 versus placebo significantly improved daily average pain at Weeks 2, 6, and 7 (all P<0.05). Numerical improvements were observed on the FIQR total score and several sleep items showed statistically significant improvements with ASP0819 versus placebo. There were no major safety concerns with ASP0819. Headache was the most common treatment-emergent adverse event (TEAE) occurring in both study arms; most TEAEs were mild or moderate in severity and no TEAEs suggestive of potential drug abuse were observed, as assessed by TEAE reporting and/or safety evaluations. Withdrawal effects also were not observed. CONCLUSION: ASP0819 demonstrated some signals suggestive of efficacy and had a good tolerability profile in patients with fibromyalgia. Further studies are required to determine if ASP0819 can be a novel non-opioid treatment option in this patient group. CLINICALTRIALSGOV REGISTRATION: NCT03056690.

A Phase I, Randomized, Double-Blind, Laser-Evoked Potential Study to Evaluate the Analgesic/Antihyperalgesic Effect of ASP9226, a State-Dependent N-Type Voltage-Gated Calcium Channel Inhibitor, in Healthy Male Subjects.

Objective: Evaluate the analgesic/antihyperalgesic effects of ASP9226, a state-dependent N-type voltage-gated calcium channel inhibitor, in healthy male subjects. Design: Randomized, double-blind, double-dummy, placebo- and active comparator-controlled crossover study. Setting: HPR Dr. Schaffler GmbH, Munich, Germany. Subject: Healthy male subjects aged 18-55 years. Methods: Twenty-four eligible subjects were randomly assigned to one of four treatment sequences and received single doses of ASP9226 (30 mg or 50 mg), pregabalin (150 mg), or placebo during four treatment periods. Laser-evoked potentials (LEP) and postlaser pain visual analog scales (VAS) on capsaicin-treated skin were assessed during main assessment days (the first day of each study period). Primary and secondary end points were the differences in LEP N2-P2 peak-to-peak (PtP) amplitudes and VAS score, respectively, in all subjects. Results: Overall, treatment with pregabalin resulted in a significantly lower LEP N2-P2 PtP amplitude vs placebo (-3.30 µV, P < 0.0001). There were no clinically relevant differences in N2-P2 PtP amplitudes between placebo and either ASP9226 dose (-0.31 µV and -0.27 µV). Furthermore, subjects reported significantly lower VAS pain scores with pregabalin vs placebo (-9.90%, P < 0.0001) in contrast to ASP9226 30 mg (-2.1%) and ASP9226 50 mg (1.2%) vs placebo. Subgroup analysis of LEP and VAS pain in participants with positive prestudy capsaicin response (n = 13) were in keeping with results in all subjects. Conclusions: ASP9226 was well tolerated; however, there was no improvement in LEP and VAS pain scores with ASP9226 at either dose vs placebo.

The MOBILE Study-A Phase IIa Enriched Enrollment Randomized Withdrawal Trial to Assess the Analgesic Efficacy and Safety of ASP8477, a Fatty Acid Amide Hydrolase Inhibitor, in Patients with Peripheral Neuropathic Pain.

OBJECTIVE: To evaluate the analgesic efficacy and safety of ASP8477 in patients with peripheral neuropathic pain (PNP). DESIGN: Enriched enrollment randomized withdrawal. SETTING: Centers in Poland (four), Czech Republic (six), and the United Kingdom (two). SUBJECTS: Patients aged 18 years or older with PNP resulting from painful diabetic peripheral neuropathy or postherpetic neuralgia. METHODS: A four-week screening period followed by a single-blind period (six-day dose titration and three-week maintenance period with ASP8477 [20/30 mg BID]). Treatment responders (defined as a ≥30% decrease in the mean average daily pain intensity during the last three days of the single-blind period) were stratified by disease and randomized to receive placebo or continue ASP8477 during a three-week, double-blind, randomized withdrawal period. The primary end point was change in mean 24-hour average numeric pain rating scale (NPRS) from baseline to end of double-blind period. RESULTS: Among 132 patients who enrolled, 116 entered the single-blind period and 63 (ASP8477, N = 31; placebo, N = 32) completed the double-blind period. There was no difference in mean 24-hour average NPRS score (P = 0.644) or in time-to-treatment failure (P = 0.485) between ASP8477 and placebo. During the single-blind period, 57.8% of patients were treatment responders. ASP8477 was well tolerated. During the single-blind period, 22% of patients experienced at least one treatment-related adverse event (TEAE); during the double-blind period, 8% in the ASP8477 arm and 18% in the placebo arm experienced at least one TEAE. CONCLUSIONS: ASP8477 was well tolerated in patients with PNP; however, ASP8477 did not demonstrate a significant treatment difference compared with placebo.

Hypothalamic-pituitary-adrenal axis and depression symptom effects of an arginine vasopressin type 1B receptor antagonist in a one-week randomized Phase 1b trial.

BACKGROUND: Arginine vasopressin 1B receptor (V1B) antagonists may have utility for the treatment of major depressive disorder (MDD). METHODS: The V1B antagonist ABT-436 (N = 31) or matching placebo (N = 20) was administered to MDD subjects for 7 days. The main study objectives were to assess the safety and hypothalamic-pituitary-adrenal axis (HPA) effects of ABT-436 in MDD subjects. MDD symptoms were assessed using the 17-item Hamilton Depression Rating Scale (HAM-D-17) and the subject-rated Mood and Anxiety Symptom Questionnaire (MASQ). RESULTS: The most prevalent safety finding associated with ABT-436 800 mg QD was increased mild-moderate diarrhea (68% v 5%, p < 0.001). Increased nausea (26% v 5%, p < 0.10), decreased systolic blood pressure (3.15-3.44 mmHg, p < 0.10) and increased heart rate (3.42-4.01 bpm, p < 0.05) were also associated with ABT-436 800 mg QD. Basal HPA activity measured by 24-hr urine total glucocorticoids was 25% lower with ABT-436 than placebo (p < 0.001). The reduction was, on average, larger in subjects with higher baseline urine total glucocorticoids. Results on plasma adrenocorticotrophic hormone (ACTH), urine, serum and saliva cortisol, and saliva cortisone also showed basal HPA attenuation with ABT-436. Dynamic HPA activity measured by plasma ACTH and serum cortisol responses to corticotrophin releasing hormone (CRH) were 30-46% lower in ABT-436 subjects (all p < 0.001). Each ABT-436 subject showed response to CRH in or near the baseline range of responses. ABT-436 was associated with more favorable symptom changes on two of five MASQ subscales (estimated effect size 1.47-1.86, p < 0.01) but not on HAM-D-17. CONCLUSIONS: The results support further clinical study of the antidepressant potential of ABT-436.

A Phase 2, Double-Blind, Placebo-Controlled Randomized Trial Assessing the Efficacy of ABT-436, a Novel V1b Receptor Antagonist, for Alcohol Dependence.

Alcohol use disorder has been linked to dysregulation of the brain stress systems, producing a negative emotional state leading to chronic relapsing behavior. Vasopressin receptors appear to have a regulatory role in stress, anxiety, and alcohol. This study evaluated the novel compound, ABT-436, a V1b receptor antagonist, in alcohol-dependent participants in a 12-week clinical trial. Men and women (n=150) who met criteria for DSM-IV alcohol dependence were recruited across four sites. Participants received double-blind ABT-436 or placebo, and a computerized behavioral intervention. ABT-436 was titrated to 800 mg/day during weeks 2-12. Although the primary outcome, percentage of heavy drinking days, was lower in participants receiving ABT-436 compared with placebo, this difference was not statistically significant (31.3 vs 37.6, respectively; p=0.172; d=0.20). However, participants receiving ABT-436 had significantly greater percentage of days abstinent than those receiving placebo (51.2 vs 41.6, respectively; p=0.037; d=0.31). No significant differences were found between treatment groups on any other measures of drinking, alcohol craving, or alcohol-related consequences. Smokers receiving ABT-436 smoked significantly fewer cigarettes per week than those receiving placebo (p=0.046). ABT-436 was well tolerated, with diarrhea (mild-to-moderate severity) being the most common side effect. In subgroup analyses, participants with relatively higher baseline levels of stress responded better to ABT-436 than placebo on select drinking outcomes, suggesting there may be value in testing medications targeting the vasopressin receptor in high stress, alcohol-dependent patients.

Single-Dose Interaction Study of the Arginine Vasopressin Type 1B Receptor Antagonist ABT-436 and Alcohol in Moderate Alcohol Drinkers.

BACKGROUND: ABT-436, a potent and selective arginine vasopressin (AVP) type 1B receptor (V1B ) antagonist, has previously demonstrated basal hypothalamic-pituitary-adrenal (HPA) axis attenuation in man. A V1B antagonist is hypothesized as an alcohol-dependent treatment based on the role of the V1B receptor in stress regulation and the finding that stress is a trigger for relapse in alcoholics. A V1B antagonist has shown favorable effects in rat models of alcohol dependence. A single-dose clinical study was conducted to assess the potential for pharmacokinetic or pharmacodynamic interaction between ABT-436 and alcohol. METHODS: Twenty moderate alcohol drinkers each received the 4 possible combinations of a single 1,000 mg ABT-436 dose (or matching placebo) and a single 0.5 g/kg alcohol dose (or placebo for alcohol) in a double-blind, randomized, 4-period crossover study. Plasma ABT-436 and blood alcohol levels were measured to assess pharmacokinetic interactions. A computerized cognitive test battery (CDR System), Bond-Lader Visual Analog Scales scales, and a postural stability test were used to measure the effects of alcohol and the potential interaction with ABT-436. The pharmacologic effect of ABT-436 was assessed by measuring serum cortisol. RESULTS: Neither ABT-436 nor alcohol affected the blood levels of the other. Alcohol reduced performance on 2 of 5 CDR System composite variables (power of attention, p = 0.002; quality of secondary episodic memory, p < 0.001), and decreased postural stability (p = 0.043). ABT-436 did not exacerbate those deleterious effects. ABT-436 reduced serum cortisol (p < 0.001), and alcohol did not significantly diminish this expected effect on the HPA axis. CONCLUSIONS: No pharmacokinetic or pharmacodynamic interaction between ABT-436 and alcohol was observed.

Clinical safety and hypothalamic-pituitary-adrenal axis effects of the arginine vasopressin type 1B receptor antagonist ABT-436.

RATIONALE: Arginine vasopressin type 1B receptor (V1B) receptor antagonism is considered a potential therapeutic for diseases with hypothalamic-pituitary-adrenal (HPA) axis dysregulation. OBJECTIVES: The aim of the present study was to evaluate the safety and pharmacodynamics of ABT-436, a selective V1B antagonist, in healthy adults. METHODS: Healthy adults received daily oral doses of ABT-436 in two clinical trials. In a dose escalation trial, nine subjects received each of 100, 500, or 800 mg ABT-436, or placebo, in the morning for 7-14 days. In a crossover trial on two 7-day regimens, 20 subjects received 200 mg ABT-436 each morning or each evening. Pharmacokinetics, measures of basal HPA axis activity, and safety were assessed in both trials. RESULTS: Mild gastrointestinal intolerance was more common with ABT-436 treatment, compared to placebo, and showed dose dependence. Mean increases and decreases of systolic blood pressure (at different times), and mean pulse increases, were observed in subjects who received 800 mg ABT-436. Mean decreases of plasma adrenocorticotrophic hormone (ACTH), serum cortisol, urine total glucocorticoids, and urine cortisol, compared to placebo, were observed following 7 daily doses of 500 and 800 mg ABT-436. Statistically significant mean differences of plasma ACTH, serum cortisol, and urine total glucocorticoids were observed between morning and evening regimens of 200 mg ABT-436. The largest observed differences were near the times of maximum post-dose ABT-436 plasma concentrations. CONCLUSIONS: ABT-436 regimens of 200-800 mg once daily (QD) for 7 days attenuated basal HPA axis activity. The results support further evaluation of ABT-436 for treatment of disorders in which HPA axis dysregulation may have an etiologic role.

Suicidality and divalproex sodium: analysis of controlled studies in multiple indications.

BACKGROUND: Recent analyses of antiepileptic drugs have indicated an increase in the risk of suicidality. The objective of this report was to provide clinical information and an independent meta-analysis of divalproex sodium and suicidality events by analyzing data from 13 placebo-controlled studies and 1 low-dose controlled study. METHODS: Adverse events considered to be possibly suicide related were identified using the Columbia Classification Algorithm of Suicide Assessment (C-CASA) methodology. Indications included epilepsy, bipolar disorder, migraine prophylaxis, impulsive aggression, and dementia. Narratives were produced for every event, and suicidality event ratings were performed by a third party blinded to treatment assignment. Statistical analyses were conducted using methodology similar to that reported by the US Food and Drug Administration (FDA). RESULTS: Suicidality events were identified in 5 of the 13 placebo-controlled studies. Of the 1,327 (0.83%) subjects taking divalproex sodium, 11 had suicidality events: 2 suicide attempts and 9 suicidal ideation. Of 992 (0.91%) subjects taking placebo, 9 had suicidality events: 1 preparatory act toward suicide, 2 suicide attempts, and 6 suicidal ideation. Across placebo-controlled studies, the overall estimated odds ratio (OR) of suicidal behavior or ideation was 0.72 (95% CI 0.29 to 1.84). The OR for suicidal behavior was 0.37 (95% CI 0.04 to 2.58), and the OR for suicidal ideation was 0.90 (95% CI 0.31 to 2.79). CONCLUSIONS: In this meta-analysis, divalproex sodium does not appear to increase the risk of suicide-related adverse events relative to placebo in the populations studied. Clinicians should nonetheless remain vigilant in assessing suicidality, not only in patients treated for mental disorders with inherently high suicide risk, but also in patients taking antiepileptic medications.

Clobazam in the treatment of Lennox-Gastaut syndrome.

PURPOSE: This randomized, double-blind, dose-ranging study evaluated safety and efficacy of clobazam (CLB) as adjunctive therapy for drop seizures in patients with Lennox-Gastaut syndrome (LGS). METHODS: Sixty-eight patients with LGS aged 2-26 years were administered CLB (low dose = target 0.25 mg/kg/day; high dose = target 1.0 mg/kg/day). The study consisted of 4-week baseline, 3-week titration, and 4-week maintenance periods, followed by a 3-week taper or continuation in an open-label study. Seizure frequency was recorded in a diary by the parent/caregiver throughout the study. RESULTS: Weekly drop seizure rates were significantly reduced from baseline in both the high-dose and low-dose groups; the reduction was significantly greater in the high-dose group. A significantly greater proportion of patients in the high-dose group experienced reductions in drop seizures of >or=25%, >or=50%, and >or=75% compared to the low-dose group; more patients in the high-dose group experienced a 100% reduction, but the difference was not significant. Nondrop seizures were also reduced in a dose-dependent manner. In both investigator and parent/caregiver global evaluations, patients in the high-dose group showed significantly greater improvements in overall symptoms compared to low-dose CLB. Adverse events were generally mild or moderate, and were similar between dose groups. Five serious adverse events were reported in four patients, but in no case was CLB discontinued. CONCLUSIONS: Clobazam was well tolerated and reduced drop seizure rates; high-dose CLB was more effective than low-dose CLB. Other seizure types were also reduced.

Adjunctive divalproex and hostility among patients with schizophrenia receiving olanzapine or risperidone.

OBJECTIVE: This study compared the specific antihostility effects of atypical antipsychotic monotherapy (olanzapine or risperidone) with that of combination treatment with divalproex sodium among patients with schizophrenia experiencing an acute psychotic episode. METHODS: A total of 249 inpatients with schizophrenia were randomly assigned to receive olanzapine plus placebo, olanzapine plus divalproex, risperidone plus placebo, or risperidone plus divalproex in a double-blind, 28-day multicenter trial. The target daily dose was 15 milligrams for olanzapine, 6 milligrams for risperidone, and up to 30 milligrams per kilogram (minimum, 15 milligrams per kilogram) for divalproex. The hostility item of the Positive and Negative Syndrome Scale (PANSS) was the principal outcome measure. Covariates included the PANSS items reflecting positive symptoms of schizophrenia (delusions, suspiciousness/persecution, grandiosity, unusual thought content, conceptual disorganization, and hallucinatory behavior). RESULTS: Combination treatment with risperidone or olanzapine plus divalproex was associated with different scores on the hostility item of the PANSS compared with antipsychotic monotherapy. Combination therapy had a significantly greater antihostility effect at days 3 and 7 than monotherapy. This result was not seen beyond the first week of treatment, but there was a trend toward a difference in effect for the entire treatment period. The effect on hostility appears to be statistically independent of antipsychotic effect on other PANSS items reflecting delusional thinking, a formal thought disorder, or hallucinations. CONCLUSIONS: Divalproex sodium may be useful as an adjunctive agent in specifically reducing hostility in the first week of treatment with risperidone or olanzapine among patients with schizophrenia experiencing an acute psychotic episode.

The safety and early efficacy of oral-loaded divalproex versus standard-titration divalproex, lithium, olanzapine, and placebo in the treatment of acute mania associated with bipolar disorder.

BACKGROUND: Previous studies have examined the safety and tolerability of oral-loaded divalproex sodium in the treatment of acute mania, but not the early efficacy of this dosing strategy. The purpose of this study was to evaluate the early efficacy of oral-loaded divalproex. METHOD: In this pooled analysis, 348 subjects from 3 randomized, double-blind, parallel-group, active- or placebo-controlled studies were used to compare the efficacy, safety, and tolerability of oral-loaded divalproex with standard-titration divalproex, lithium, olanzapine, or placebo. Subjects were inpatients diagnosed with acute mania associated with bipolar I disorder (DSM-III-R or -IV and SADS-Change Version). Patients were administered oral-loaded divalproex (20 or 30 mg/kg/day on days 1 and 2 followed by 20 mg/kg/day, and increased at physician's discretion), standard-titration divalproex initiated at 250 mg t.i.d. and titrated to 40-150 microg/mL, lithium (300 mg t.i.d. initial dose) titrated to 0.4 to 1.5 mEq/L, olanzapine (10 mg q.d. initial dose) up to 20 mg/day, or placebo. RESULTS: The results demonstrate an early efficacy advantage for oral-loaded divalproex compared to standard-titration divalproex at days 5, 7/8, and 10. Efficacy was improved over lithium on day 7/8. There were no efficacy differences between divalproex loading and olanzapine. Divalproex loading showed greater efficacy than placebo at all time points. Divalproex loading was as well tolerated or better tolerated than the other active treatments as measured by adverse events and changes in laboratory parameters. CONCLUSION: These results suggest the oral loading of divalproex leads to a more rapid antimanic effect when compared with standard-titration divalproex, lithium, or placebo and is better tolerated than olanzapine and as well tolerated as lithium or standard-titration divalproex.

Divalproex in the treatment of impulsive aggression: efficacy in cluster B personality disorders.

Impulsive aggressive behavior is common in psychiatric disorders and accounts for significant morbidity and mortality. However, little systematic treatment data exist from placebo-controlled trials for this symptom domain. This was a multicenter, randomized, double-blind, placebo-controlled study in which outpatients with a score of > or =15 on the Aggression scale of the Overt Aggression Scale-Modified (OAS-M) and who fulfilled DSM-IV criteria for Cluster B personality disorder (n=96), intermittent explosive disorder (n=116), or post-traumatic stress disorder (n=34) were randomized to divalproex sodium or placebo for 12 weeks duration. Based on average OAS-M Aggression scores over the last 4 weeks of treatment, a treatment effect was not observed in the intent-to-treat data set (combined across the three psychiatric disorders), but was observed in both intent-to-treat and evaluable data sets for patients with Cluster B personality disorders. In the Cluster B evaluable data set, statistically significant treatment differences favoring divalproex were also observed for component items of the OAS-M Aggression score, including verbal assault and assault against objects, as well as OAS-M Irritability score, and Clinical Global Impression (CGI)-Severity at multiple time points throughout the study. No treatment group difference was noted for overall premature discontinuation rate; however, across psychiatric diagnoses, 21 (17%) patients in the divalproex group prematurely discontinued because of an adverse event, as compared to 4 (3%) patients in the placebo group (p <0.001). While a treatment effect was not observed when all diagnostic groups were combined, in a large subgroup of patients with Cluster B disorders, divalproex was superior to placebo in the treatment of impulsive aggression, irritability, and global severity.

Effect of divalproex combined with olanzapine or risperidone in patients with an acute exacerbation of schizophrenia.

This double-blind, randomized, multicenter study investigated the use of divalproex with an antipsychotic agent in patients hospitalized for acute exacerbation of schizophrenia. Patients (n = 249) who met DSM-IV criteria for schizophrenia were randomly assigned to receive olanzapine monotherapy, risperidone monotherapy, divalproex plus olanzapine, or divalproex plus risperidone for 28 days. Divalproex was initiated at 15 mg/kg/day and titrated over 12 days to a maximum dosage of 30 mg/kg/day. Olanzapine and risperidone, were, respectively, initiated at 5 and 2 mg/day and were titrated over the first 6 days to respective target fixed daily dosages of 15 and 6 mg/day. Improvements from baseline were observed at all evaluation points throughout the 28-day treatment period in the two combination therapy and the two antipsychotic monotherapy groups, with statistically significant treatment differences favoring combination therapy as soon as day 3 for Positive and Negative Syndrome Scale (PANSS) total score, derived Brief Psychiatric Rating Scale (BPRSd) total score, as well as PANSS and BPRSd subscales. These findings were confirmed in post hoc repeated-measures analyses of variance in which treatment differences favoring combination therapy were observed for PANSS total (p = 0.020) and PANSS positive scale scores (p = 0.002). Both combination therapy and antipsychotic monotherapy were well tolerated. Treatment with divalproex in combination with an atypical antipsychotic agent resulted in earlier improvements in a range of psychotic symptoms among acutely hospitalized patients with schizophrenia. Further evaluation is warranted to confirm these findings.

A novel approach to assess inter-rater reliability in the use of the Overt Aggression Scale-Modified.

The ability of raters to apply measures of efficacy accurately and reproducibly in clinical trials of psychotropic medications is vital to the validity of study data. In a large, multi-center trial using the Overt Aggression Scale-Modified (OAS-M), inter-rater reliability was evaluated using standardized patients (SP) in a live 'mock' interview. Thirty raters experienced in the OAS-M each interviewed two actors trained to portray patients with intermittent explosive disorder, borderline and antisocial personality disorder, and/or post-traumatic stress disorder. Inter-rater reliability of OAS-M scores was evaluated using the intra-class correlation coefficient (ICC). The joint reliability of the raters in the study with an expert rater was also assessed by an ICC. The ICC was 0.96 between the raters, and 0.98 between the raters and expert rater. Results suggest that SP can be utilized in rater assessment and that raters administering the OAS-M in this model of rater reliability assessment demonstrate a high level of consistency and reliability. The method described here may be useful in future assessments of inter-rater reliability.

An open-label trial of divalproex in children and adolescents with bipolar disorder.

OBJECTIVE: This study evaluated the safety and effectiveness of divalproex sodium (Depakote ) in the treatment of youths with bipolar disorder. METHOD: Forty bipolar disorder patients aged 7 to 19 years, with a manic, hypomanic, or mixed episode, enrolled in an open-label study of divalproex (2-8 weeks), followed by a double-blind, placebo-controlled period (8 weeks). RESULTS: Twenty-two subjects (61%) showed > or =50% improvement in Mania Rating Scale (MRS) scores during the open-label period. Significant ( <.001) improvements from baseline were seen for mean scores of all efficacy measures, including the MRS, Manic Syndrome Scale, Behavior and Ideation Scale, Brief Psychiatric Rating Scale, Clinical Global Impressions Severity scale, and Hamilton Rating Scale for Depression. Of the 23 subjects who discontinued the study during the open-label period, 6 (15%) discontinued for ineffectiveness, 6 (15%) for intolerance, 6 (15%) for noncompliance, and 6 (15%) for other reasons. Adverse events were generally mild or moderate in severity, with the most common being headache, nausea, vomiting, diarrhea, and somnolence. Laboratory data results were unremarkable. Too few subjects participated in the double-blind period for statistical analysis. CONCLUSION: This study provides preliminary support for the safety and effectiveness of divalproex in the treatment of bipolar disorder in youths.