Atomoxetine - Treatment of attention deficit hyperactivity disorder: Beyond stimulants

Among the pharmacotherapeutic interventions for attention deficit hyperactivity disorder (ADHD), psychostimulants have been the drugs of choice for many years. However, some patients do not adequately respond to or cannot tolerate stimulant treatment. Among nonstimulants for ADHD, the most extensively studied and the only one approved for use in the United States is the norepinephrine reuptake inhibitor atomoxetine. This paper reviews atomoxetine's chemistry and putative mechanism of action, as well as its clinical pharmacokinetics, metabolism, and efficacy and safety in acute clinical trials. (c) 2004 Prous Science. All rights reserved.

Cardiovascular effects of atomoxetine in children, adolescents, and adults

BACKGROUND

Atomoxetine is a highly specific presynaptic inhibitor of the noradrenaline (norepinephrine) transporter that was recently approved in the US for the treatment of patients with attention-deficit/hyperactivity disorder (ADHD). Adverse effects on the cardiovascular system, including abnormalities in heart rate, blood pressure, or cardiac rhythm have been associated with several noradrenergic medications.

OBJECTIVE

To further elucidate the magnitude and impact of blood pressure and pulse elevations in patients taking atomoxetine.

STUDY DESIGN

Short-term cardiovascular safety in children, adolescents, and adults with ADHD was assessed in five randomised, double-blind trials (duration up to 10 weeks) with atomoxetine (n = 612) or placebo (n = 474). Long-term cardiovascular safety in children and adolescents (n = 169) was assessed in patients who entered an open-label extension or a blinded continuation following short-term treatment.

METHODS

Adverse events, blood pressure, sitting pulse, and electrocardiograms (ECGs) were collected throughout the trials. QT intervals were corrected for heart rate by a data-specific correction factor (QTcD; derived from baseline ECGs) as well as standard methods.

RESULTS

Atomoxetine treatment was associated with small but statistically significant increases in mean systolic blood pressure in adults and diastolic blood pressure in children and adolescents. Mean pulse rate increased for all atomoxetine treatment groups. The increases in blood pressure and pulse tended to occur early in therapy, stabilised, and returned toward baseline upon drug discontinuation. There was no significant difference between atomoxetine and placebo treatment groups in change in QTcD interval for all study populations. Palpitations in the adult patient population were the only significant cardiovascular adverse event (p = 0.037) occurring more frequently in the atomoxetine treatment group (3.7%) than in the placebo group (0.8%). Discontinuations due to cardiovascular-related events were very uncommon in the adult group, and did not occur in the child/adolescent group.

CONCLUSION

While atomoxetine has noradrenergic activity, increases in pulse and blood pressure were small and of little, if any, clinical significance. Atomoxetine was not associated with QT interval prolongation. Cardiovascular effects of atomoxetine were minimal, and atomoxetine was well tolerated in short- and long-term studies.

Drug development process for a product with a primary pediatric indication

This article reviews the drug development process in the United States, focusing on practical issues and new U.S. Food and Drug Administration (FDA) regulations and guidance for developing a drug with a primary pediatric indication. Atomoxetine, a novel treatment for attention-deficit/ hyperactivity disorder (ADHD), is used to illustrate how the modern drug development process works and to highlight changes in the development of ADHD treatments since the introduction of the stimulants over 50 years ago. In addition to dealing with unique regulatory requirements and guidance, developing a drug for use in a pediatric population poses novel challenges in diverse areas including biomedical ethics, developmental pharmacology, and clinical trial design and implementation.

Atomoxetine in adults with ADHD: two randomized, placebo-controlled studies

BACKGROUND

[corrected] Attention-deficit/hyperactivity disorder (ADHD) has been less studied in adults than in children, and the treatment studies reported to date have been small, single-center trials. To assess the efficacy of atomoxetine, a new and highly selective inhibitor of the norepinephrine transporter, we conducted two large, multicenter treatment trials.

METHODS

Two identical studies using randomized, double-blind, placebo-controlled designs and a 10-week treatment period were conducted in adults with DSM-IV-defined ADHD as assessed by clinical history and confirmed by a structured interview (study I, n = 280; study II, n = 256). The primary outcome measure was a comparison of atomoxetine and placebo using repeated measures mixed model analysis of postbaseline values of the Conners' Adult ADHD Rating Scale.

RESULTS

In each study, atomoxetine was statistically superior to placebo in reducing both inattentive and hyperactive and impulsive symptoms as assessed by primary and secondary measures. Discontinuations for adverse events among atomoxetine patients were under 10% in both studies.

CONCLUSION

Atomoxetine appears to be an efficacious treatment for adult ADHD. Its lack of abuse potential may be an advantage for many patients.

Cerebral blood volume and clinical changes on the third day of placebo substitution for SSRI treatment

BACKGROUND

Interruptions in SSRI treatment have been associated with adverse effects that can resemble depressive illness. We hypothesized that brain regions implicated in depression, with extensive serotonergic innervation, would exhibit changes in activity associated with emergence of symptoms following drug discontinuation.

METHODS

Subjects meeting DSM-IV criteria for remitted major depression on 20 mg/day of either fluoxetine or paroxetine were recruited into this 6-week study. During weeks 2 and 6, subjects underwent a 3-day period in which either active drug or placebo was substituted for their medication under double-blind conditions. Cerebral blood volume (CBV) maps were obtained via dynamic susceptibility magnetic resonance imaging at the end of each double-blind period.

RESULTS

In the paroxetine group, change in CBV in left medial superior frontal region and left caudate nucleus correlated significantly with change in Discontinuation Emergent Symptom Scale and Hamilton Depression Rating Scale (HDRS; R2 = 0.66, p =.0007; R2 = 0.51, p =.006; and R2 = 0.43, p =.015; R2 = 0.32, p =.043, respectively).

CONCLUSIONS

These data demonstrate that changes in regional CBV of left prefrontal cortex and left caudate nucleus correlate with the emergence of discontinuation symptoms and increased HDRS after interruption of paroxetine treatment.

Once-daily atomoxetine treatment for children and adolescents with attention deficit hyperactivity disorder: a randomized, placebo-controlled study

OBJECTIVE

The authors assessed the efficacy of once-daily atomoxetine administration in the treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD).

METHOD

In a double-blind study, children and adolescents with ADHD (N=171, age range=6-16 years) were randomly assigned to receive 6 weeks of treatment with either atomoxetine (administered once daily) or placebo.

RESULTS

Outcomes among atomoxetine-treated patients were superior to those of the placebo treatment group as assessed by investigator, parent, and teacher ratings. The treatment effect size (0.71) was similar to those observed in previous atomoxetine studies that used twice-daily dosing. Parent diary ratings suggested that drug-specific effects were sustained late in the day. Discontinuations due to adverse events were low (less than 3%) for both treatment groups, and no serious safety concerns were observed.

CONCLUSIONS

Once-daily administration of atomoxetine is an effective treatment for children and adolescents with ADHD.

Atomoxetine and methylphenidate treatment in children with ADHD: a prospective, randomized, open-label trial

OBJECTIVE

To assess the comparability of atomoxetine, a new therapy for attention-deficit/hyperactivity disorder (ADHD) and methylphenidate. (Atomoxetine was originally called tomoxetine. The name was recently changed in order to avoid any potential confusion with tamoxifen that might lead to errors in dispensing drug.)

METHOD

Children with ADHD were randomized to open-label atomoxetine or methylphenidate for 10 weeks. Response was assessed with the ADHD-IV Rating Scale.

RESULTS

Two hundred twenty-eight patients were randomized (atomoxetine n = 184, methylphenidate n = 44). Both drugs were associated with marked improvement in inattentive and hyperactive-impulsive symptom clusters as assessed by parents and investigators. No statistically significant differences between treatment groups were observed on the primary outcome measure (investigator-rated ADHD-IV Rating Scale total score: atomoxetine baseline: 39.4 [8.5], endpoint: 20.0 [13.9]; methylphenidate baseline: 37.6 [9.7], endpoint: 19.8 (16.6); p = .66). Safety and tolerability were also similar between the 2 drugs. Discontinuations due to adverse events were 10/184 (5.4%) for atomoxetine and 5/44 (11.4%) for methylphenidate; p = .175.

CONCLUSION

These data provide preliminary evidence that atomoxetine is associated with therapeutic effects comparable to those of methylphenidate.

Effects of oral estrogen, raloxifene and arzoxifene on gene expression in serotonin neurons of macaques

The serotonin neural system contributes to cognition and affect, both of which exhibit pathologies with gender bias. We previously showed that estrogen (E) treatment of female macaques via Silastic implant alters gene expression for tryptophan hydroxylase (TPH), the serotonin reuptake transporter (SERT) and the 5HT1A autoreceptor. In addition, we have found that serotonin neurons of macaques express ER beta (ER beta). Together these studies suggest that the serotonin neural system could transduce the action of estrogen via ER beta on aspects of mood and cognition. However, estrogen replacement therapy can increase the risk for breast and uterine cancer. Therefore, we questioned whether the selective estrogen receptor modulators, raloxifene and arzoxifene, act in a manner similar to E on gene expression in serotonin neurons of a nonhuman primate model. Female rhesus macaques were ovariectomized and orally dosed with vehicle, estradiol 17beta, raloxifene or arzoxifene once per day by sipper bottles for 30 days. The animals were then euthanized and the midbrains were prepared for in situ hybridization for TPH, SERT and 5HT1A receptor mRNAs followed by densitometric analysis. There was a significant increase in TPH total signal (positive pixelsxOD) with E, raloxifene and arzoxifene, respectively. There was a significant decrease in SERT mRNA optical density with all treatments. 5HT1A autoreceptor mRNA did not change with any treatment. If these changes in gene expression are reflected by similar changes in the functional proteins, then raloxifene or arzoxifene could increase serotonin neurotransmission with little or no negative action in peripheral tissues. In conclusion, the selective estrogen receptor modulators, raloxifene and arzoxifene, act in a manner similar to natural E on TPH and SERT mRNA expression in serotonin neurons. This suggests that raloxifene and arzoxifene are agonists at ER beta in the context of the serotonin neuron. However, the responses to E were more variable and less robust with the oral dosing paradigm compared to a chronic implant paradigm.

Mirtazapine, yohimbine or olanzapine augmentation therapy for serotonin reuptake-associated female sexual dysfunction: a randomized, placebo controlled trial

BACKGROUND

Many agents have been proposed as potential treatments for SSRI-associated sexual dysfunction, but few placebo-controlled trials have been reported.

METHOD

After a 1-month baseline evaluation, pre-menopausal women with moderate to severe sexual dysfunction associated with the institution of fluoxetine therapy were randomized to augmentation therapy with placebo (N=39), mirtazapine (N=36), yohimbine (N=35) or olanzapine (N=38) for a 6-week period. Outcomes were measured using a daily diary, a biweekly self-report assessment, and a computer assisted structured interview.

RESULTS

At baseline, orgasm was most severely impaired. After 6 weeks, there was statistically significant improvement on most measures for the overall group of patients, however there were few differences between treatment groups. Isolated treatment differences were observed for the patient self-report of overall sexual function (olanzapine superior to placebo) and the structured interview sexual satisfaction item (mirtazapine inferior to placebo).

CONCLUSION

No drug assessed was consistently associated with differences from placebo. The results of the study do not support uncontrolled reports of efficacy for these agents in premenopausal women.

Efficacy of usual antidepressant dosing regimens of fluoxetine in panic disorder: randomised, placebo-controlled trial

BACKGROUND

Although serotonin reuptake inhibitors are effective in panic disorder, questions concerning whether doses associated with antidepressant efficacy are also effective for panic disorder remain.

AIMS

To assess the efficacy of the usual antidepressant dose of fluoxetine in treating full panic attacks.

METHOD

Patients with panic disorder were randomised to placebo or to fluoxetine initiated at 10 mg daily for 1 week and then increased to 20 mg daily. The trial lasted 12 weeks, but after 6 weeks patients who had failed to achieve a satisfactory response were eligible for dose escalation to a maximum of 60 mg of fluoxetine daily.

RESULTS

Fluoxetine was associated with a statistically significantly greater proportion of panic-free patients compared with placebo after 6 weeks and at end-point.

CONCLUSIONS

Fluoxetine at a dose of 20 mg daily is safe and efficacious in reducing symptoms of panic disorder. Patients who fail to obtain a satisfactory response at 20 mg daily may benefit from further dose increases.

Atomoxetine in the treatment of children and adolescents with attention-deficit/hyperactivity disorder: a randomized, placebo-controlled, dose-response study

OBJECTIVE

Atomoxetine is an investigational, nonstimulant pharmacotherapy being studied as potential treatment for attention-deficit/hyperactivity disorder (ADHD). It is thought to act via blockade of the presynaptic norepinephrine transporter in the brain. We assessed the efficacy of 3 doses of atomoxetine compared with placebo in children and adolescents with ADHD.

METHODS

A total of 297 children and adolescents who were 8 to 18 years of age and had ADHD as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, were randomized to placebo or atomoxetine dosed on a weight-adjusted basis at 0.5 mg/kg/day, 1.2 mg/kg/day, or 1.8 mg/kg/day for an 8-week period. ADHD symptoms, affective symptoms, and social and family functioning were assessed using parent and investigator rating scales.

RESULTS

Approximately 71% of children enrolled were male, approximately 67% met criteria for mixed subtype (both inattentive and hyperactive/impulsive symptoms), and the only common psychiatric comorbidity was oppositional defiant disorder (approximately 38% of the sample). At baseline, symptom severity was rated as moderate to severe for most children. At endpoint, atomoxetine 1.2 mg/kg/day and 1.8 mg/kg/day were consistently associated with superior outcomes in ADHD symptoms compared with placebo and were not different from each other. The dose of 0.5 mg/kg/day was associated with intermediate efficacy between placebo and the 2 higher doses, suggesting a graded dose-response. Social and family functioning also were improved in the atomoxetine groups compared with placebo with statistically significant improvements in measures of children's ability to meet psychosocial role expectations and parental impact. Discontinuations as a result of adverse events were <5% for all groups.

CONCLUSION

Among children and adolescents aged 8 to 18, atomoxetine was superior to placebo in reducing ADHD symptoms and in improving social and family functioning symptoms. Atomoxetine was associated with a graded dose-response, and 1.2 mg/kg/day seems to be as effective as 1.8 mg/kg/day and is likely to be the appropriate initial target dose for most patients. Treatment with atomoxetine was safe and well tolerated.

Changes in sexual function during acute and six-month fluoxetine therapy: a prospective assessment

Sexual dysfunction has been reported as an unwanted effect associated with selective serotonin reuptake inhibitors therapy, but the nature and frequency of such effects have not been characterized systematically. Sexual function was assessed in depressed patients participating in a multicenter trial of acute and continuation fluoxetine therapy using a 4-item self-rated scale. Patients were evaluated at study entry, after 13 weeks of fluoxetine 20 mg daily, and during 25 weeks of continuation therapy with fluoxetine 20 mg daily, fluoxetine 90 mg weekly, or placebo. In a 13-week open-label trial, among 501 patients who met Diagnostic and Statistical Manual of Mental Disorders criteria for depression, 51.6% of women and 40.6% of men reported improvement, 35.0% of women and 41.9% of men reported no change, and 13.4% of women and 17.4% of men reported worsening in overall sexual function. During double-blind continuation therapy, there were no statistically significant differences in change in sexual function between treatments. Worsened sexual function that occurred during continuation treatment was strongly associated with worsened depressive symptoms. Depression is associated with sexual dysfunction, and improvement in sexual functioning related to the antidepressant effects of fluoxetine may be more common than drug-associated deterioration in sexual function. Among patients who report worsening, effects may be most pronounced on orgasm. Deterioration in sexual function does not appear to be a late-onset drug-specific event, but is strongly related to worsening depressive symptoms.

Abnormalities in response to vasopressin infusion in chronic fatigue syndrome

Several neuroendocrine studies have suggested hypoactivation of the hypothalamic-pituitary-adrenal axis in chronic fatigue syndrome. One possible determinant of this neuroendocrine abnormality, as well as the primary symptom of fatigue, is reduced hypothalamic secretion of corticotropin-releasing hormone (CRH). Because CRH and vasopressin secreted from the hypothalamus act synergistically at the pituitary to activate ACTH secretion, the ACTH response to peripheral infusion of vasopressin can provide an indirect measure of hypothalamic CRH secretion. We measured the ACTH and cortisol response to a one hour infusion of arginine vasopressin in 19 patients with chronic fatigue syndrome and 19 age and sex matched healthy volunteers. Patients with chronic fatigue syndrome had a reduced ACTH response to the vasopressin infusion and a more rapid cortisol response to the infusion. These results provide further evidence of reduced hypothalamic CRH secretion in patients with chronic fatigue syndrome.

Brain kinetics of paroxetine and fluoxetine on the third day of placebo substitution: a fluorine MRS study

OBJECTIVE

This study tested whether a relationship exists between concentration and response following discontinuation of selective serotonin reuptake inhibitors.

METHOD

Eight patients with remitted major depression who were taking 20 mg/day of either fluoxetine or paroxetine underwent placebo substitution for 3 days. Serum drug and brain fluorine levels were obtained before and after placebo substitution.

RESULTS

With placebo substitution, a mean of 88% (SD=13%) of brain fluorine signal from fluoxetine (plus fluorinated metabolites) remained, compared with a mean of 38% (SD=17%) of the brain fluorine signal from paroxetine (plus fluorinated metabolites). Among patients taking paroxetine, adverse events during placebo substitution correlated highly with steady-state brain drug levels.

CONCLUSIONS

The correlation of clinical effects with brain drug levels in the paroxetine group suggests that relationships between drug response and brain drug concentrations merit further investigation.

Interruption of selective serotonin reuptake inhibitor treatment. Double-blind, placebo-controlled trial

BACKGROUND

Abrupt interruption of therapy with selective serotonin reuptake inhibitors (SSRIs) has been associated with somatic and psychological symptoms.

AIMS

Systematically to assess symptoms and effects on daily functioning related to interruption of SSRI therapy.

METHOD

Patients treated with fluoxetine, setraline or paroxetine underwent identical five-day periods of treatment interruption and continued active treatment under double-blind, order-randomised conditions, with regular assessment of new symptoms.

RESULTS

Placebo substitution for paroxetine was associated with increases in the number and severity of adverse events following the second missed dose, and increases in functional impairment at five days. Placebo substitution for sertraline resulted in less pronounced changes, while interruption of fluoxetine was not associated with any significant increase in symptomatology.

CONCLUSIONS

Abrupt interruption of SSRI treatment can result in a syndrome characterised by specific physical and psychological symptoms. Incidence, timing and severity of symptoms vary among SSRIs in a fashion that appears to be related to plasma elimination characteristics.

Female sexual dysfunction associated with antidepressant administration: a randomized, placebo-controlled study of pharmacologic intervention

OBJECTIVE

Few controlled trials of pharmacologic intervention in women with antidepressant-associated sexual dysfunction have been reported, and there is uncertainty about the usefulness of putative treatments and the assessment methodologies. The authors evaluated the efficacy of buspirone and amantadine in the treatment of sexual dysfunction associated with fluoxetine administration.

METHOD

Women who had been successfully treated with fluoxetine for at least 8 weeks and who had reported a deterioration in sexual function not present before the initiation of fluoxetine entered a 4-week assessment period. After assessment they were randomly assigned to an 8-week treatment trial with buspirone (N=19), amantadine (N=18), or placebo (N=20). Outcomes were assessed by using a patient-rated daily diary and a clinician-rated structured interview.

RESULTS

While the amantadine-treated women did report significantly greater improvements in energy levels than women in the placebo group, all treatment groups experienced improvement in overall sexual function as well as in most individual measures. There were no statistically significant differences among the three groups.

CONCLUSIONS

Neither buspirone nor amantadine was more effective than placebo in ameliorating antidepressant-associated sexual dysfunction. All groups experienced marked nonspecific improvement during treatment, which suggests the importance of placebo-controlled trials for this condition.

Hormonal markers of stress response following interruption of selective serotonin reuptake inhibitor treatment

Depressive illness is associated with loss of the usual regulation of stress-responsive hormonal and neurotransmitter systems, and antidepressants have intrinsic effects reducing the activity of these systems. Abrupt interruption of treatment with some antidepressants has been associated with a self-limited syndrome of physical and psychological symptoms distinct from relapse, of which drug half-life appears to be the major determinant. We hypothesized that reactivation of stress-response systems could play a role in this syndrome and studied the effects of treatment interruption in patients successfully treated with the antidepressant fluoxetine, paroxetine or sertraline. During placebo substitution, interruption of paroxetine was associated with statistically significant increases in plasma IGF-1 and heart rate. These data suggest that some activation of physiologic stress-responses may accompany symptom increases during treatment interruption of shorter half-life agents.

Changes in weight during a 1-year trial of fluoxetine

OBJECTIVE

Fluoxetine has been associated with weight loss during acute treatment, but no controlled studies of weight change during long-term treatment with fluoxetine or other selective serotonin reuptake inhibitors have been reported. Weights were assessed for patients whose depressive symptoms had disappeared with acute fluoxetine treatment. Patients were then randomly assigned to continuation treatment with fluoxetine or placebo.

METHOD

Patients whose illness had remitted after 12 weeks of treatment with fluoxetine, 20 mg/day, were randomly assigned to receive up to 38 weeks of treatment with fluoxetine or placebo. Weight was assessed at each visit. Change in weight was analyzed during the initial 12 weeks of acute treatment and after 14, 26, and 38 weeks. Relationships between weight change and body mass index and between weight change and appetite change were assessed.

RESULTS

During the initial 4 weeks of therapy, a mean absolute weight decrease of 0.4 kg was observed for all patients. Among patients who completed 50 weeks of therapy, the mean absolute weight increase during continuation treatment was similar for both the placebo- and fluoxetine-treated groups. Weight increase was not related to initial body mass index but was related to both poor appetite at study entry and to improvement in appetite after recovery. No patients discontinued therapy because of weight gain.

CONCLUSIONS

Acute therapy with fluoxetine is associated with modest weight loss. After remission of depressive symptoms, weight gain for patients taking fluoxetine for longer periods is not different from that for patients taking placebo and is most likely related to recovery from depression.

Changes in adverse events reported by patients during 6 months of fluoxetine therapy

BACKGROUND

Although a period of 6 to 12 months of antidepressant therapy is recommended for most patients with depression, systematic examinations of the course of adverse events over time, the resolution of early-onset events, and the possible emergence of later-onset events are limited. We examined the safety of fluoxetine, 20 mg/day, in a large, prospective, long-term treatment trial, and we report a comparison of early- and late-onset adverse events and the course of adverse events over 26 weeks of treatment.

METHOD

Adverse events were recorded at each visit in a uniform format by open-ended questioning, regardless of perceived causality. New or worsened events reported in either the first 4 weeks of treatment (early-reporting interval) or weeks 22 through 26 of treatment (late-reporting interval) were compared.

RESULTS

Patients (N = 299) whose depression (DSM-III-R) remitted with 12 weeks of fluoxetine treatment entered continuation therapy, and 174 completed 26 weeks of therapy. All events that occurred in > or =5% of patients early in treatment decreased in frequency over time (p<.05), and no events occurred significantly more frequently during continuation therapy. No previously uncommon adverse events became common during long-term treatment.

CONCLUSION

Common adverse events associated with initiating fluoxetine treatment in depressed patients, including nausea, insomnia, nervousness, and somnolence, resolve in the majority of patients and become significantly less frequent with continued treatment over a 6-month period. No adverse events present initially become more frequent late in treatment. Therapy with fluoxetine, 20 mg/day, is well tolerated over 6 months, and most adverse events observed early in treatment resolve.

Continuing treatment of panic disorder after acute response: randomised, placebo-controlled trial with fluoxetine. The Fluoxetine Panic Disorder Study Group

BACKGROUND

Data concerning appropriate treatment in panic disorder following an initial response to acute therapy are limited.

AIMS

To assess the safety and efficacy of continued fluoxetine treatment following successful acute therapy of panic disorder.

METHOD

Patients who responded to acute fluoxetine treatment were randomised to 24 weeks of continued fluoxetine or placebo.

RESULTS

Fluoxetine responders randomised to continue on their acute-phase fluoxetine dose experienced statistically significant improvement in panic attack frequency and phobia rating scale score over 24 weeks of therapy, while those switched to placebo experienced statistically significant worsening in Hamilton Anxiety (HAM-A), Hamilton Depression (HAM-D) and SCL-90-R rating scores.

CONCLUSIONS

Fluoxetine was associated with improved clinical outcomes compared with placebo during continuation therapy.

Outcome assessment and clinical improvement in panic disorder: evidence from a randomized controlled trial of fluoxetine and placebo. The Fluoxetine Panic Disorder Study Group

OBJECTIVE

Although panic attacks account for only a portion of the morbidity of panic disorder and panic attack frequency assessments are unreliable, studies of drug efficacy in panic disorder have generally used reduction in panic attack frequency as the primary measure of improvement. The authors studied the efficacy of fluoxetine treatment in panic disorder and measured the relative contributions of changes in symptoms to overall improvement.

METHOD

Patients with a diagnosis of panic disorder (N = 243) were randomly assigned to treatment with 10 or 20 mg/day of fluoxetine or placebo. Primary outcome measures were change in panic attack frequency and clinician-rated Clinical Global Impression improvement scores. Other assessments included a panic attack inventory, clinician-rated and patient-rated versions of the Panic and Phobic Disorder Change Scale, a phobia rating scale, the Hamilton Anxiety Rating Scale, the 21-item Hamilton Depression Rating Scale, and the Sheehan Disability Scale. Correlations were determined between outcomes in individual symptom domains and overall clinical outcome.

RESULTS

Fluoxetine, particularly the 20-mg/day dose, was associated with more improvement than was placebo in patients with panic disorder across multiple symptom measures, including global improvement, total panic attack frequency, phobic symptoms, and functional impairment. Global improvement was most highly correlated with reductions in overall anxiety and phobic symptoms and least correlated with reduction in panic attacks. Fluoxetine treatment for panic disorder was well tolerated, with a safety profile consistent with that observed for fluoxetine in other disorders.

CONCLUSIONS

These data provide support for the efficacy and safety of fluoxetine treatment in reducing panic attacks, phobic symptoms, anxiety, and depressive symptoms in patients with panic disorder. Reductions in panic attack frequency in subjects given either fluoxetine or placebo were less closely related to overall clinical improvement than reductions in phobic avoidance, anxiety, depressive symptoms, and functional impairment, suggesting that outcome measures in this disorder should be more broadly based.

Optimal length of continuation therapy in depression: a prospective assessment during long-term fluoxetine treatment

OBJECTIVE

The purpose of this study was to determine prospectively the optimal length of therapy in a long-term, placebo-controlled continuation study of patients who responded to acute fluoxetine treatment for major depression (defined by DSM-III-R).

METHOD

The study was conducted at five outpatient psychiatric clinics in the United States. Patients who met criteria for remission after 12 or 14 weeks of open-label acute fluoxetine therapy, 20 mg/day (N=395 of 839 patients), were randomly assigned to one of four arms of a double-blind treatment study (50 weeks of placebo, 14 weeks of fluoxetine and then 36 weeks of placebo, 38 weeks of fluoxetine and then 12 weeks of placebo, or 50 weeks of fluoxetine). Relapse rate was the primary outcome measure. Both Kaplan-Meier estimates and observed relapse rates were assessed in three fixed 12-week intervals after double-blind transfers from fluoxetine to placebo at the start of the double-blind period and after 14 and 38 weeks of continued fluoxetine treatment.

RESULTS

Relapse rates (Kaplan-Meier estimates) were lower among the patients who continued to take fluoxetine compared with those transferred to placebo in both the first interval, after 24 total weeks of treatment (fluoxetine, 26.4%; placebo, 48.6%), and the second interval, after 38 total weeks of treatment (fluoxetine, 9.0%; placebo, 23.2%). In the third interval, after 62 total weeks of treatment, rates were not significantly different between the groups (fluoxetine, 10.7%; placebo, 16.2%).

CONCLUSIONS

Patients treated with fluoxetine for 12 weeks whose depressive symptoms remit should continue treatment with fluoxetine for at least an additional 26 weeks to minimize the risk of relapse.

Safety of abrupt discontinuation of fluoxetine: a randomized, placebo-controlled study

Selective serotonin reuptake inhibitors may be associated with new adverse events after abrupt discontinuation. Hypothesizing that the long half-life of fluoxetine would be protective, this study analyzed the effects of abrupt fluoxetine discontinuation during a randomized, double-blind, placebo-controlled study of depression maintenance treatment. After 12 weeks of fluoxetine treatment (20 mg/day), 395 responders were abruptly randomized to placebo (N = 96) or to continued fluoxetine (N = 299). Patients were seen at weeks 1, 2, 4, and 6 after randomization. Reports of new or worsened adverse events were similar for both groups at each visit after randomization. Patient discontinuations related to adverse events were also similar in both groups. Mild, self-limited lightheadedness or dizziness occurred in a small percentage of patients who discontinued fluoxetine treatment but was of little clinical significance. No cluster of symptoms suggestive of a discontinuation syndrome was observed. Abrupt discontinuation of fluoxetine treatment was well tolerated and did not seem to be associated with significant clinical risk. Fluoxetine may offer a potential safety advantage over shorter-acting agents with respect to treatment interruption and/or discontinuation and may be a better choice for those patients who are likely to miss doses because of travel or forgetfulness.

Pathophysiologic and somatic investigations of hypothalamic-pituitary-adrenal axis activation in patients with depression

Preclinical studies of inflammatory and autoimmune illnesses have demonstrated the importance of central components of the HPA axis in disease pathophysiology. The implications of these data for human illness are poorly understood. We have studied the pathophysiology of the hypercortisolism seen in two human illnesses involving the central nervous system, multiple sclerosis (MS) and depression, and looked for demonstrable somatic changes that may be associated with such hypercortisolism. Data from a study of medication-free patients with multiple sclerosis not in acute exacerbation suggest that compared with depression, MS is associated with increased prominence of hypothalamic vasopressin secretion (p < 0.05). Data from studies of depressed patients with mild to moderate hypercorticolism (assessed by 24-hour urinary free cortisol excretion) demonstrate marked reductions in bone mineral density compared to healthy, carefully matched controls (p < 0.001), as well as changes in markers of bone metabolic activity similar to those seen in patients with Cushing's disease or exogenous glucocorticoid treatment (p < 0.05). Taken together, these studies suggest HPA axis dysregulations demonstrated in preclinical models of autoimmune and inflammatory illness also occur in human illness and may have important and lasting somatic sequelae.

Hormonal and metabolic responses to exercise across time of day and menstrual cycle phase

Two studies, each utilizing short-term treadmill exercise of a different intensity, assessed the metabolic and hormonal responses of women to exercise in the morning (AM) and late afternoon (PM). In study 1, plasma concentrations of growth hormone, arginine vasopressin, catecholamines, adrenocorticotropic hormone, cortisol, lactate, and glucose were measured before, during, and after high-intensity exercise (90% maximal O2 uptake) in the AM and PM. In study 2, plasma concentrations of adrenocorticotropic hormone, cortisol, lactate, and glucose were measured before, during, and after moderate-intensity exercise (70% maximal O2 uptake) in the AM and PM in the follicular (days 3-9), midcycle (days 10-16), and luteal (days 18-26) phases of the menstrual cycle. The results of studies 1 and 2 revealed no significant diurnal differences in the magnitude of responses for any measured variable. In addition, study 2 revealed a significant time-by-phase interaction for glucose (P = 0. 014). However, net integrated responses were similar across cycle phases. These data suggest that metabolic and hormonal responses to short-term, high-intensity exercise can be assessed with equal reliability in the AM and PM and that there are subtle differences in blood glucose responses to moderate-intensity exercise across menstrual cycle phase.

Chronic imipramine is associated with diminished hypothalamic-pituitary-adrenal axis responsivity in healthy humans

The hypercortisolism of melancholic depression is thought to reflect hypothalamic hypersecretion of CRH and may be related to the hyperarousal associated with this syndrome. Although chronic administration of imipramine to experimental animals significantly decreases CRH messenger RNA levels in the paraventricular nucleus, it is generally thought that resolution of hypercortisolism following recovery from depression is related to the improvement in mood and decrease in anxiety that accompanies recovery rather than an intrinsic effect of imipramine. The present study was designed to explore whether chronic imipramine administration to healthy, nondepressed volunteers is associated with effects on hypothalamic-pituitary-adrenal (HPA) axis function. We studied basal and provocative measures of HPA axis function in 14 healthy volunteers before and after 6 weeks of imipramine treatment at therapeutic doses. Imipramine was associated with decreased responses in peak ACTH and cortisol to ovine CRH and in peak ACTH to arginine vasopressin (P = 0.02, P = 0.003, and P = 0.02, respectively) without changes in indices of basal HPA axis function. These data are consistent with preclinical findings and support the hypothesis that imipramine has an intrinsic effect on central components of HPA axis function, potentially related to its therapeutic effects.

Exercise and circadian rhythm-induced variations in plasma cortisol differentially regulate interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor-alpha (TNF alpha) production in humans: high sensitivity of TNF alpha and resistance of IL-6

Although we have previously shown that the integrity of inflammatory mediator-induced activation of the hypothalamic-pituitary-adrenal axis is essential for conferring resistance to inflammatory disease in susceptible Lewis rats, the role of endogenous glucocorticoid secretion in human immune function in either health or disease is less clear. To further understand the relevance of physiological variations in plasma cortisol on immune function in humans, we evaluated ex vivo lipopolysaccharide-induced interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor-alpha (TNF alpha) production in the whole blood of healthy volunteers studied under conditions chosen to approximate either physiological or pharmacological glucocorticoid levels. Administration of a pharmacological dose of hydrocortisone suppressed the production of all three cytokines, whereas administration of a physiological dose of hydrocortisone suppressed only TNF alpha production. Stress-induced levels of glucocorticoids, achieved during exercise at 100% maximal oxygen utilization, suppressed IL-1 beta and TNF alpha production, but were without effect on IL-6 production. In addition, circadian variations of cortisol were associated with decreased TNF alpha production, but were without effect on IL-1 beta or IL-6 production. These studies challenge the generally accepted idea that glucocorticoids consistently suppress cytokine production and indicate a hierarchy of sensitivity, with TNF alpha having the greatest sensitivity, IL-1 beta having intermediate sensitivity, and IL-6 being resistant. The resistance of IL-6 production to glucocorticoid suppression is compatible with data suggesting an antiinflammatory as well as a proinflammatory action for this cytokine.

Fluoxetine and norfluoxetine plasma concentrations in major depression: a multicenter study

OBJECTIVE

Prior studies examining the relationship between fluoxetine plasma concentrations and response in major depression have either found no relationship between plasma concentration and response or suggested a curvilinear relationship with a therapeutic window. To elucidate this relationship, plasma concentrations of fluoxetine, norfluoxetine, fluoxetine plus norfluoxetine, and fluoxetine/norfluoxetine ratio were compared to therapeutic response.

METHOD

A total of 839 patients (577 women, 262 men; mean age = 40 [SD = 11] with a DSM-III-R diagnosis of major affective disorder who were in the course of either depression or bipolar disorder not otherwise specified and had a minimum baseline score of 16 on the 17-item Hamilton Depression Rating Scale were initially treated. Response was defined as follows: 1) nonresponders had less that a 50% or more reduction from baseline Hamilton depression score, 2) nonremitting responders had a 50% or more reduction from baseline Hamilton depression score but a final score higher than 7, and 3) remitters had a final Hamilton Depression score of 7 or lower. Plasma fluoxetine and norfluoxetine concentrations were measured after 8 weeks of fixed-dose treatment of 20 mg/day.

RESULTS

Plasma concentration data were available from 615 patients. Plasma concentration were similar in responders, both remitting and nonremitting (N = 411), and nonresponders (N = 204) for fluoxetine concentrations, for norfluoxetine concentrations, as well as for the sum of fluoxetine and norfluoxetine and for the ratio of fluoxetine to norfluoxetine. No apparent relationship was observed between plasma drug concentration and clinical response.

CONCLUSION

Plasma concentrations of fluoxetine and norfluoxetine do not appear to be related to clinical outcome and should not be used to make treatment decisions.

The effect of assessment method and respondent population on utilities elicited for Gaucher disease

Measured preferences have been reported to vary with the method of elicitation and respondent population surveyed. We elicited utilities for Gaucher disease using a multimedia implementation of the time trade-off, standard gamble, and a conceptually different, largely untested approach, the risk-risk trade-off, from those who are healthy, those with a chronic illness and those with Gaucher disease. The risk-risk trade-off produced significantly lower utilities than the other two preference assessment methods and had the poorest test-retest reliability. The respondent's self-rated current health state utility was the most important determinant of utility values elicited by the time trade-off and standard gamble for the hypothetical health states. Our results do not support the use of our implementation of the risk-risk trade-off method. In eliciting preferences for hypothetical health states from the general population, the subjective rating of a respondent's own health state should be considered in determining representative population groups.

Bone mineral density in women with depression

BACKGROUND

Depression is associated with alterations in behavior and neuroendocrine systems that are risk factors for decreased bone mineral density. This study was undertaken to determine whether women with past or current major depression have demonstrable decreases in bone density.

METHODS

We measured bone mineral density at the hip, spine, and radius in 24 women with past or current major depression and 24 normal women matched for age, body-mass index, menopausal status, and race, using dual-energy x-ray absorptiometry. We also evaluated cortisol and growth hormone secretion, bone metabolism, and vitamin D-receptor alleles.

RESULTS

As compared with the normal women, the mean (+/-SD) bone density in the women with past or current depression was 6.5 percent lower at the spine (1.00+/-0.15 vs. 1.07+/-0.09 g per square centimeter, P=0.02), 13.6 percent lower at the femoral neck (0.76+/-0.11 vs. 0.88+/-0.11 g per square centimeter, P<0.001), 13.6 percent lower at Ward's triangle (0.70+/-0.14 vs. 0.81+/-0.13 g per square centimeter, P<0.001), and 10.8 percent lower at the trochanter (0.66+/-0.11 vs. 0.74+/-0.08 g per square centimeter, P<0.001). In addition, women with past or current depression had higher urinary cortisol excretion (71+/-29 vs. 51+/-19 micrograms per day [196+/-80 vs. 141+/-52 nmol per day], P=0.006), lower serum osteocalcin concentration (P=0.04), and lower urinary excretion of deoxypyridinoline (P=0.02).

CONCLUSIONS

Past or current depression in women is associated with decreased bone mineral density.

Naloxone-induced pituitary-adrenal activation does not differ in patients with depression, obsessive compulsive disorder, and healthy controls

Adrenocorticotropic hormone (ACTH) and cortisol secretion have been shown to be abnormal in approximately half of depressed patients. Information from pituitary and adrenal studies suggests that the locus of this dysregulation is at or above the level of the hypothalamus; however, direct evidence from provocative studies of the hypothalamic corticotropin releasing hormone (CRH) neuron does not exist. The current study was designed to stimulate hypothalamic CRH release using the opiate antagonist naloxone in patients with depression and elevated urinary-free cortisols as well as healthy and psychiatric controls. All subjects received naloxone and placebo on separate days in a double-blinded, randomized fashion at a dose determined previously to reliably induce significant increases in ACTH and cortisol secretion. No significant differences were noted among groups. We conclude that although naloxone is an effective central stimulant of the hypothalamic CRH neuron, stimulation of the hypothalamic CRH neuron with naloxone does not provide evidence of dysregulation of the HPA axis in depression.

Stress and antidepressants differentially regulate neurotrophin 3 mRNA expression in the locus coeruleus

The mechanisms by which stress and anti-depressants exert opposite effects on the course of clinical depression are not known. However, potential candidates might include neurotrophic factors that regulate the development, plasticity, and survival of neurons. To explore this hypothesis, we examined the effects of stress and antidepressants on neurotrophin expression in the locus coeruleus (LC), which modulates many of the behavioral and physiological responses to stress and has been implicated in mood disorders. Using in situ hybridization, we demonstrate that neurotrophin 3 (NT-3) is expressed in noradrenergic neurons of the LC. Recurrent, but not acute, immobilization stress increased NT-3 mRNA levels in the LC. In contrast, chronic treatment with antidepressants decreased NT-3 mRNA levels. The effect occurred in response to antidepressants that blocked norepinephrine uptake, whereas serotonin-specific reuptake inhibitors did not alter NT-3 levels. Electroconvulsive seizures also decreased NT-3 expression in the LC as well as the hippocampus. Ntrk3 (neurotrophic tyrosine kinase receptor type 3; formerly TrkC), the receptor for NT-3, is expressed in the LC, but its mRNA levels did not change with stress or antidepressant treatments. Because, NT-3 is known to be trophic for LC neurons, our results raise the possibility that some of the effects of stress and antidepressants on LC function and plasticity could be mediated through NT-3. Moreover, the coexpression of NT-3 and its receptor in the LC suggests the potential for autocrine mechanisms of action.

IMPACT: an object-oriented graphical environment for construction of multimedia patient interviewing software

This paper describes our software for rapid construction of multimedia computer interviews. The program, which we call IMPACT, was designed to measure preferences for health outcomes using the standard gamble and other decision analytic techniques. IMPACT is also a multimedia shell program that allows researchers to interactively construct patient interviewing instruments without programming or scripting. It supports the integration of text, graphics, synthesized speech, digital sound and QuickTime movies into interviewing instruments through a point-and-click interface. IMPACT also supports branching logic and randomizing the presentation order of materials within an instrument. This allows customization of the presentation based on patient responses and facilitates experimental designs. Validation studies show that preference assessments performed using IMPACT have high test-retest reliability (r = 0.83, n = 96). Post-test surveys (n = 52) show that most subjects understand valuation methods (86%) and believe that the explanations provided were clear (96%) and that methods were reasonable (80%). The majority of subjects thought the preference assessment methods were not difficult to use (53%) and would have been comfortable using such methods for medical decisions (53%).

An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan

OBJECTIVE

To determine whether L-5-hydroxytryptophan (L-5-HTP) associated with eosinophiliamyalgia syndrome (EMS) like illness contains impurities in a fashion similar to that described in L-tryptophan associated with EMS.

METHODS

Members of a family who became ill after exposure to L-5-HTP were evaluated at the National Institutes of Health. Data from patients with extended exposure to L-5-HTP were also examined. Samples of L-5-HTP were examined using high performance liquid chromatography.

RESULTS

One member of the family had EMS, and 2 others had eosinophilia. No patient in the other group reviewed developed the syndrome, although 2 patients developed eosinophilia. The L-5-HTP used by the family contained an impurity not present in samples from the other patient group. After replacement with L-5-HTP not containing this impurity, eosinophilia in 2 family members resolved.

CONCLUSION

Some L-5-HTP contains impurities that may be related to L-5-HTP associated EMS.

Hypothalamic-pituitary-adrenal axis perturbations in patients with fibromyalgia

OBJECTIVE

To examine basal and stimulated hypothalamic-pituitary-adrenal (HPA) axis and related hormone levels, including adrenocorticotropin (ACTH), cortisol, arginine vasopressin (AVP), and neuropeptide Y (NPY), in patients with fibromyalgia (FM).

METHODS

Basal and ovine corticotropin-releasing hormone (oCRH)-stimulated HPA axis function were assessed in 12 patients with FM and in age- and sex-matched normal subjects. Basal plasma AVP levels and AVP release after postural change were assessed, and plasma NPY levels were measured in the same samples.

RESULTS

Patients with FM had low 24-hour urinary free cortisol, but normal peak and elevated trough plasma cortisol levels, compared with normal subjects. The net integrated ACTH response to oCRH in FM was not significantly different from that in normal subjects, but tended toward an exaggerated response. There was a significant decrease in net integrated cortisol response to oCRH in FM patients, indicating adrenal hyporesponsiveness. AVP levels were not significantly different between FM patients and control subjects, but variability was greater among the FM patients. Plasma NPY levels were significantly lower in FM patients than in normal subjects.

CONCLUSION

These data support the view that HPA axis function is perturbed in patients with FM. Further study is required to ascertain the cause of HPA axis perturbations and their relationship to symptoms in patients with FM.

The stress response in critical illness

Under normal, unstressed conditions, the body maintains a dynamic equilibrium known as homeostasis--a complex interplay balancing the conflicting demands presented by many internal and external forces. In the face of threatened or actual disruptions (i.e., stress), molecular, cellular, physiologic, and behavioral responses act to restore homeostasis. These responses can be specific to a particular stressor and relatively circumscribed (e.g., secretion of insulin in response to an increase in blood glucose), or can be generalized and relatively nonspecific (e.g., behavioral manifestations of severe anxiety). Typically, more nonspecific and generalized responses occur in the setting of severe and threatening disruptions in homeostasis, and taken together, these responses are known as the "general adaptation or stress syndrome". We will describe the elements and organization of the generalized stress response with particular attention to the hypothalamic-pituitary-adrenal axis as it interacts with the immune system, and we will review what is known about this interactive network in the setting of critical illness.

Developing and testing a multimedia presentation of a health-state description

Quality-adjustment weights for health states are an essential component of cost-utility analysis (CUA). Quality-adjustment weights are obtained by presenting large numbers of subjects with multiattribute descriptions of health states for rating. Comprehending multiattribute health states is a difficult task for most respondents. The authors hypothesized that multimedia (MM) presentation using computers might facilitate this task better than would a paper-based text (Text). To test this hypothesis, they developed closely matched MM and Text descriptions of health states in the first-person narrative style, and developed a method of testing the presentation of a health state. Subjects were randomized to exposure to either MM or Text and subject recall of the health state and recognition of features of the health state were tested. How well defined the preferences of the subjects were after each presentation method was assessed by having the subjects mark on a double-anchored visual-analog scale the "best" and "worst" they believed the quality of life in the health state might be. MM subjects had better recall (11.85 vs 9.44 of a total of 24 meaning units, p = 0.098) and better recognition (4.71 vs 4.22, p = 0.08). The average interval between the "best" and "worst" ratings was shorter for the MM subjects (2.19 cm vs 3.26 cm, p = 0.12).(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple sclerosis is associated with alterations in hypothalamic-pituitary-adrenal axis function

In the LEW/N rat model, a decreased hypothalamic-pituitary-adrenal (HPA) axis response to inflammatory and immune mediators confers susceptibility to the development of a variety of inflammatory and immune diseases, including experimental allergic encephalomyelitis. In humans with optic neuritis, early intervention with steroids is associated with a decrease in the number of patients who go on to develop multiple sclerosis (MS). The current study was designed to determine whether patients with MS show evidence of a hypoactive HPA axis. Thirteen patients with MS were studied at baseline and with provocative tests of HPA axis function [ovine CRH, arginine vasopressin (AVP), and ACTH stimulation]. Compared to matched controls, patients with MS had significantly higher plasma cortisol levels at baseline. Despite this hypercortisolism and in contrast to patients with depression who had similar elevations in plasma cortisol levels, patients with MS showed normal, rather than blunted, plasma ACTH responses to ovine CRH, suggesting that the pathophysiology of hypercortisolism in MS is different from that in depression. Patients with MS also showed blunted ACTH responses to AVP stimulation and normal cortisol responses to high and low dose ACTH stimulation. Taken together, these findings are compatible with data from studies of experimental animals exposed to chronic inflammatory stress, which showed mild increased activation of the HPA axis with increased relative activity of AVP in the regulation of the pituitary-adrenal axis. These data do not support a role for hypocortisolism in MS once the disease is established.

Type I glucocorticoid receptor blockade does not affect baseline or ovine corticotropin-releasing-hormone-stimulated adrenocorticotropic hormone and cortisol secretion

The type I glucocorticoid receptor antagonist spironolactone was administered to healthy volunteers to determine the effect of type I receptor blockade on adrenocorticotropic hormone (ACTH) and cortisol secretion in humans. On separate days and in a double-blind, randomized fashion, placebo and each of four increasing doses of spironolactone were administered orally to subjects. Doses were selected to be within the clinically used range and, following drug administration, baseline and ovine-corticotropin releasing hormone (oCRH)-stimulated ACTH and cortisol plasma levels were measured. In contrast to the clear effects of type II glucocorticoid receptor blockade on human pituitary adrenal function, no relationship between spironolactone dose or plasma levels and either basal or oCRH-stimulated pituitary-adrenal function was noted at doses comparable to those which induce type I receptor blockade and cardiovascular therapeutic effects in the kidney. These data suggest that, at physiologically relevant doses, type I glucocorticoid receptor blockade does not affect HPA axis function.

Imipramine reduces the local inflammatory response to carrageenin

Imipramine was administered chronically to LEW/N, outbred and F344/N rats which were then exposed to the aseptic irritant carrageenin in order to determine whether the decreased hypothalamic expression of CRH m-RNA previously shown to be associated with imipramine affects peripheral immune processes. Both LEW/N and outbred but not F344/N rats had vigorous inflammatory responses to carrageenin, and imipramine was associated with significant decreases in the local cellular inflammatory response to carrageenin. Imipramine was also associated with changes in the expression of peripheral blood cell MHC class II expression in LEW/N and outbred rats. These results suggest that at doses comparable to those used clinically imipramine has significant effects on response to an inflammatory stimulus.

The effect of chronic imipramine administration on the densities of 5-HT1A and 5-HT2 receptors and the abundances of 5-HT receptor and transporter mRNA in the cortex, hippocampus and dorsal raphe of three strains of rat

We have recently demonstrated that the LEW/N rat contains lower concentrations of cortical and hippocampal 5-HT1A receptors compared with the F344/N and out-bred HSD rats. To further characterize these strains, we investigated the effect of chronic (8 wk) imipramine administration (5 mg/kg/day) on 5-HT1A and 5-HT2 receptor densities and mRNA in the cortex and hippocampus and 5-HT transporter mRNA in the dorsal raphe of LEW/N, HSD, and F344/N rats, using quantitative autoradiography and in situ hybridization histochemistry. After imipramine treatment, a significant increase in the levels of hippocampal 5-HT1A receptors, but not mRNA, was observed in LEW/N rats while the abundance of hippocampal 5-HT1A receptor mRNA, but not 5-HT1A receptor densities, decreased in F344/N rats. Cortical and hippocampal 5-HT2 receptor densities, but not mRNA, significantly decreased after imipramine administration in all three strains. Finally, 5-HT1A receptor densities and the abundance of mRNAs encoding the 5-HT1A receptor and 5-HT transporter in the dorsal raphe remained unaltered after imipramine administration in all three strains. The effects of imipramine on the levels of cortical and hippocampal 5-HT1A and 5-HT2 receptors and their transcripts, therefore, appear to be strain-dependent. The implications of these findings are discussed.

A multimedia preference-assessment tool for functional outcomes

Functional outcomes of clinical trials are often reported as number of dependencies in activities of daily living (ADLs). Quality-weighting for the ADLs has not been reported. We designed and pilot-tested ADLIB (ADL Index Builder), a multimedia computer program, that presents ADL health states to subjects and elicits from subjects a rating for the quality of life of each health state. Subjects, who were patients over age 50 without previous computer experience, found the program easy to use. Health care professionals specializing in geriatrics confirmed that the ADL presentations used in the program are in accord with typical practice in scoring ADLs. We plan to use the program to obtain population-based preference ratings that can be used to assess efficacy of clinical trials and to provide quality-weights for cost-effectiveness analysis.