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Biomedical subjects

M A Frye

Publications and source records attributed to M A Frye.

At least 19 recordsLinked to original sources

Venlafaxine but not bupropion decreases cerebrospinal fluid 5-hydroxyindoleacetic acid in unipolar depression.

BACKGROUND: While the antidepressants venlafaxine and bupropion are known to have different neurochemical profiles in vitro, their effects on human cerebral metabolism in vivo have not been directly compared. METHODS: Cerebrospinal fluid (CSF) levels of 5-hydroxyindoleacetic acid (5-HIAA), serotonin, 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 3,4-dihydroxyphenylacetic acid (DOPAC) were examined in 14 never-hospitalized outpatients with unipolar depression and 10 age-similar healthy controls. Patients received a baseline lumbar puncture (LP), which was repeated after at least 6 weeks of randomized monotherapy with either venlafaxine or bupropion, while controls received only a baseline LP. RESULTS: Patients (n = 9) receiving venlafaxine showed a significant decrease (42%) in their CSF 5-HIAA concentrations after treatment, but no change in other CSF measures. In contrast, patients receiving bupropion (n = 8) showed no change in CSF measures compared to pretreatment values. CONCLUSIONS: While the mechanism for this differential effect of venlafaxine remains to be determined, the current study provides confirmation of the different aminergic effects of venlafaxine and bupropion.

Adult

Statistical approaches to trial durations in episodic affective illness.

In light of the high variability in illness characteristics and patterns among patients with bipolar illness, parallel group designs present severe methodologic difficulties. Crossover, off-on-off-on (B-A-B-A), and other individualized designs may be a useful substitute, but no consensus exists about how to estimate the individual trial durations required in these instances. Several methods for determining optimum trial lengths in crossover designs are presented, illustrated, and discussed. These include: chi-square (chi2) for the expected versus observed number of either episodes or days well; exceeding two standard deviations for average duration of episodes or euthymic intervals; or the Sequential Probability Ratio Test (SPRT), which detects when mean values differ from prior statistical expectations. Each method was applied to three demonstration cases using data from actual clinical trials of three patients with different patterns of recurrent affective illness. Each method detected changes in illness severity, although different tests appeared to be sensitive to differing cycle patterns in the patients illustrated. We suggest that these types of analyses and others can be used as indicator statistics to augment global impressions and clinical judgment, and to assist in determining individualized trial durations, both in formal clinical trials and in clinical treatment settings. Once individual responsivity is confirmed with an appropriate interplay of trial design and statistical analysis, the percentage response in a given population can then be compared to other agents or in other populations. Moreover, meta-analytic techniques based on addition of z scores from individuals' effect sizes can then be used to assess overall significance of a drug effect in a given population or subpopulation. The need for further development of appropriate and alternate study designs and analysis methods for bipolar illness is highlighted. Approaches to estimating required trial durations in individuals with different cycle frequencies in crossover and B-A-B-A designs constitute one element of that exploration.

Acute Disease

Relationships between thyroid hormone and antidepressant responses to total sleep deprivation in mood disorder patients.

BACKGROUND: Acute transient antidepressant effects of sleep deprivation are consistently observed in 50% of depressed patients, but the mechanisms of these, at times, dramatic improvements in mood have not been adequately elucidated. Some, but not all, studies suggest a relationship to increased thyroid-stimulating hormone (TSH) secretion. METHODS: TSH and other thyroid indices were measured at 8:00 AM after a baseline night's sleep and at 8:00 AM following a night of total sleep deprivation (S.D.) in 34 medication-free, affective disorder patients assessed with Hamilton, Beck, and Bunney-Hamburg depression ratings as well as two hourly self-ratings on a visual analog scale. RESULTS: Compared with baseline, S.D. induced highly significant increases in TSH, levothyroxine, free levothyroxine, and triiodothyronine. The 12 S.D. responders tended to have greater TSH increases than the 15 nonresponders (p < .10). The change in Beck depression ratings significantly correlated with the change in TSH (r = -.40, p = .0496, n = 24). CONCLUSIONS: These data are consistent with several other reports of a significant relationship between degree of antidepressant response to S.D. and increases in TSH measured at 8:00 AM near their usual nadir. Acute removal of the sleep-related break on the hypothalamic-pituitary-thyroid axis remains a promising candidate for the mechanism of sleep deprivation-induced improvement in mood in depressed patients.

Adult

Clozapine in bipolar disorder: treatment implications for other atypical antipsychotics.

Traditional neuroleptics are often utilized clinically for the management of bipolar disorder. Although effective as antimanic agents, their mood stabilizing properties are less clear. Additionally, their acute clinical side effect profile and long term risk of tardive dyskinesia, particularly in mood disorder patients, portend significant liability. This review focuses on the use of atypical antipsychotics in the treatment of bipolar disorder focusing on clozapine as the prototypical agent. Although, preclinical research and clinical experience suggest that the atypical antipsychotics are distinctly different from typical antipsychotics, they themselves are heterogeneous in profiles of neuropharmacology, clinical efficacy, and tolerability. The early clinical experience of clozapine as a potential mood stabilizer suggests greater antimanic than antidepressant properties. Conversely, very preliminary clinical experience with risperidone suggests greater antidepressant than antimanic properties and some liability for triggering or exacerbating mania. Olanzapine and sertindole are under investigation in psychotic mood disorders. The foregoing agents and future drugs with atypical neuroleptic properties should come to play an increasingly important role, compared to the older classical neuroleptics, in the acute and long term management of bipolar disorder.

Antidepressive Agents

Beyond lithium in the treatment of bipolar illness.

Dramatic changes have recently occurred in the availability of treatment options for bipolar illness. Second generation mood stabilizing anticonvulsants carbamazepine and valproate are now widely used as alternatives or adjuncts to lithium. High potency benzodiazepines are also used as alternatives to typical neuroleptics, and now atypical neuroleptics are demonstrating efficacy and better side-effects profiles than the typicals. Thyroid augmentation strategies and dihydropyridine L-type calcium channel blockers require further clinical trials to define their role. Putative third generation mood stabilizing anticonvulsants lamotrigine, gabapentin, and topiramate have unique mechanisms of action and deserve further systematic study, as does the potential role for nonconvulsive brain stimulation with repeated transcranial magnetic stimulation (rTMS). These and a host of other potential treatment options now require a new generation of clinical trials to help identify clinical and biological markers of response and optimal use alone and in complex combination therapeutic regimens.

Antimanic Agents

Nimodipine monotherapy and carbamazepine augmentation in patients with refractory recurrent affective illness.

Of 30 patients with treatment-refractory affective illness, 10 showed a moderate to marked response to blind nimodipine monotherapy compared with placebo on the Clinical Global Impressions Scale. Fourteen inadequately responsive patients (3 unipolar [UP], 11 bipolar [BP]) were treated with the blind addition of carbamazepine. Carbamazepine augmentation of nimodipine converted four (29%) of the partial responders to more robust responders. Patients who showed an excellent response to the nimodipine-carbamazepine combination included individual patients with patterns of rapid cycling, ultradian cycling, UP recurrent brief depression, and one with BP type II depression. When verapamil was blindly substituted for nimodipine, two BP patients failed to maintain improvement but responded again to nimodipine and remained well with a blind transition to another dihydropyridine L-type calcium channel blocker (CCB), isradipine. Mechanistic implications of the response to the dihydropyridine L-type CCB nimodipine alone and in combination with carbamazepine are discussed.

Adult

Gabapentin does not alter single-dose lithium pharmacokinetics.

Lithium (Li) and gabapentin are both exclusively eliminated by renal excretion. When used in combination, a competitive drug-drug interaction could possibly alter Li renal excretion with important clinical implications considering the rather narrow therapeutic index of Li. This study examined the single-dose pharmacokinetic profiles of Li in 13 patients receiving placebo and then steady-state gabapentin (mean daily dose: 3,646.15 mg). During both phases, a single 600-mg dose of Li was orally administered with serial Li levels obtained at time zero and at 0.25, 0.5, 1, 2, 3, 4, 8, 12, 24, 48, and 72 hours. The pharmacokinetic parameters assessed were the following: area under the concentration time curve (AUC) for Li, maximal concentration of Li (Li Cmax), and time to reach peak Li concentration (Li Tmax). For patients receiving gabapentin, the mean Li AUC at 72 hours was 9.91+/-3.54 mmol x hr/mL and did not differ significantly from the mean Li AUC of 10.19+/-2.89 mmol x hr/mL for patients receiving placebo. The mean Li Cmax was 0.69+/-0.13 mmol/L for gabapentin patients and did not differ from the mean Li Cmax of 0.72+/-0.15 mmol/L for placebo patients. The mean serum Li Tmax was 1.38+/-0.62 hours for gabapentin patients and did not differ significantly from the mean serum Li Tmax of 1.5+/-0.91 hours for placebo patients. These data indicate that gabapentin treatment at this high therapeutic dose does not cause clinically significant alterations in short-term Li pharmacokinetics in patients with normal renal function. These preliminary data warrant further controlled study in a larger, more heterogenous patient sample and a longer duration of assessment, but they do suggest that these two medications may be administered in combination for the management of bipolar disorder.

Acetates

A history of the use of anticonvulsants as mood stabilizers in the last two decades of the 20th century.

Anticonvulsants have moved into an important position as alternatives and adjuncts to lithium carbonate in the treatment of bipolar illness. Work with the nonhomologous model of kindled seizures helped in the choice of carbamazepine as a potential mood stabilizer and in the study of the mechanisms of action of the second generation anticonvulsants carbamazepine and valproate, as well as the putative third generation psychotropic anticonvulsants lamotrigine and gabapentin. Anticonvulsant neuropeptides such as TRH and nonconvulsant approaches with repeated transcranial magnetic stimulation (rTMS) also appear promising.

Anticonvulsants

Cost reduction with maintenance ECT in refractory bipolar disorder.

A case report of outpatient maintenance electroconvulsive therapy (ECT) is presented in a patient with bipolar disorder type I refractory to conventional medication treatment but responsive to ECT. A cost comparison is made showing substantial savings when outpatient maintenance ECT is used in lieu of inpatient hospitalization with ECT. A detailed life chart illustrating multiple medication trials that failed to stabilize the patient accompanies the financial summary. This case highlights the advantages of outpatient maintenance ECT for bipolar depression particularly with regard to safety, efficacy, and significant health care cost reduction.

Adult

Rapid cycling bipolar affective disorder: lack of relation to hypothyroidism.

Thyroid indices were measured after an extended period of medication-free evaluation averaging 6 weeks in 67 consecutively admitted patients with bipolar illness. Thyroid hormone levels -- thyroxine (T4), free T4 and triiodothyronine (T3) -- were not significantly different in the 31 rapid cyclers (> or = 4 affective episodes/year) than in 36 non-rapid cyclers. Analysis of covariance indicated a non-significant trend relation between higher T4 and a greater number of affective episodes in the year prior to admission and male gender when age was covaried. Several previous reports, primarily in medicated subjects, have suggested a link between rapid cycling patients and decreased peripheral thyroid indices (low hormone levels and elevated TSH), but now the majority of studies do not support such a relation. Among those in the literature, this study includes patients studied for the longest time off medications and further suggests that the commonly-cited relation between subclinical hypothyroidism and rapid cycling bipolar illness be reevaluated.

Adult

Comparative antidepressant effects of intravenous and intrathecal thyrotropin-releasing hormone: confounding effects of tolerance and implications for therapeutics.

A significant amount of preclinical and human data indicate that thyrotropin-releasing hormone (TRH) has antidepressant effects. Although early studies showing these effects using intravenous TRH were not consistently replicated, it has been suggested that this could be explained by its poor blood-brain barrier penetration. For this reason we compared the antidepressant effect of intrathecal and intravenous TRH administered in a double-blind design to 2 treatment-refractory patients with bipolar II disorder. Each experienced a robust antidepressant response by both routes; subsequent open trials of intravenous TRH also were effective until apparent tolerance developed. Intrathecal TRH was readministered and both subjects again experienced robust antidepressant responses. These preliminary data suggest a differential mechanism of tolerance to the two routes of administration and raise the possibility that a subgroup of patients may be responsive to the antidepressant effects of TRH independent of its route of administration.

Affect

Alternative approaches to refractory depression in bipolar illness.

Thus, there appears to be a large variety of approaches to refractory bipolar depression. In contrast to several decades ago, wherein augmentation of lithium with antidepressants and neuroleptics was essentially the only treatment mode available, a panoply of treatment options now exist. However, their relative efficacy in different illness subtypes and stages remains to be better delineated, as do their optimal sequencing and use in combination in individual patients. It is the opinion of these authors and many of our colleagues in the field that initial use of several mood stabilizer drugs in combination may have a preferable long-term outcome in some rapid cycling patients, compared with the immediate use of a unimodal antidepressant with an inadequate single mood stabilizer, although this remains to be systematically studied. The use of thyroid augmentation strategies would appear to have merit in relationship to not only the potential treatment of lithium-related hypothyroidism, but also in augmenting antimanic and antidepressant effects. As one moves toward some of the complex combination treatment strategies discussed in this chapter, one has to be particularly careful about drug interactions and their potential for toxicity as well as therapeutic effects. Perhaps a prevailing guideline would be to use these agents more carefully in combination therapy than in monotherapy, with slow upward titration of dose to individual patients' side effects thresholds, even in preference to targeting of conventional blood level windows. In this way, side effects can be avoided during the assessment of complex combination regimens. In addition, one should be aware of potential pharmacokinetic interactions. For example, with the addition of valproate to carbamazenine, one should reduce the dose of carbamazepine, as valproate will not only increase the free fraction of carbamazepine based on displacement of protein binding, but will lead to increased accumulation of carbamazepine-10,11-epoxide. This epoxide is not measured in conventional assays but could contribute to the side effects profile (Ketter and Post, 1994). Similarly, valproate will markedly increase blood levels of lamotrigine; the starting dose of this agent should be substantially lower than conventional dosage when these two drugs are used in combination. We suggest the utility of detailed mapping with a formal system-such as the Life Chart Methodology (LCM) (Leverich and Post, 1996)-of mood fluctuation vs. medications in order to optimize and rationalize complex combination therapy. In this way, not only can the nuances of partial response be better defined, but also basic decisions about the therapeutic index and relative likelihood of response can be more readily assessed. We have discussed the other merits of the life chart method as an important clinical treatment tool as well as a research tool in other venues, but reemphasize its potential great importance in the treatment of refractory cyclic bipolar patients, in whom an initial period of remission of depression may, in many instances, be as likely attributable to the natural course of illness as the current intervention being offered. As such, it behooves the clinician to have a systematic database for the more subtle issues of dose titration and sequential addition of medications in complex combination regimens. In the face of inefficiency to one combination strategy, how one moves to the next strategy remains a highly individualized, clinically-based algorithm. We suggest the potential utility of moving towards a new set of mood stabilizers and then repeating some of the unimodal antidepressant additions and augmentation trials in an attempt to overcome refractory depression. Refractory depression in bipolar patients should be viewed as a medical emergency in light of the high potential for suicide in the illness in general (Chen and Dilsaver, 1996) and in patients who have either sustained or episodic refracto

Bipolar Disorder

The place of anticonvulsant therapy in bipolar illness.

With the increasing recognition of lithium's inadequacy as an acute and prophylactic treatment for many patients and subtypes of bipolar illness, the search for alternative agents has centered around the mood stabilizing anticonvulsants carbamazepine and valproate. In many instances, these drugs are effective alone or in combination with lithium in those patients less responsive to lithium monotherapy, including those with greater numbers of prior episodes, rapid-cycling, dysphoric mania, co-morbid substance abuse or other associated medical problems, and patients without a family history of bipolar illness in first-degree relatives. Nineteen double-blind studies utilizing a variety of designs suggest that carbamazepine, or its keto-congener oxcarbazepine, is effective in acute mania; six controlled studies report evidence of the efficacy of valproate in the treatment of acute mania as well. Fourteen controlled or partially controlled studies of prophylaxis suggest carbamazepine is also effective in preventing both manic and depressive episodes. valproate prophylaxis data, although based entirely on uncontrolled studies, appear equally promising. Thus, both drugs are widely used and are now recognized as major therapeutic tools for lithium-nonresponsive bipolar illness. The high-potency anticonvulsant benzodiazepines, clonazepam and lorazepam, are used adjunctively with lithium or the anticonvulsant mood stabilizers as substitutes or alternatives for neuroleptics in the treatment of manic breakthroughs. Preliminary controlled clinical trials suggest that the calcium channel blockers may have antimanic or mood-stabilizing effects in a subgroup of patients. A new series of anticonvulsants has just been FDA-approved and warrant clinical trials to determine their efficacy in acute and long-term treatment of mania and depression. Systematic exploration of the optimal use of lithium and the mood-stabilizing anticonvulsants alone and in combination, as well as with adjunctive antidepressants, is now required so that more definitive treatment recommendations for different types and stages of bipolar illness can be more strongly evidence based.

Affect

Increased neural cell adhesion molecule in the CSF of patients with mood disorder.

Neural cell adhesion molecule (N-CAM) is involved in cell-cell interactions during synaptogenesis, morphogenesis, and plasticity of the nervous system. Disturbances in synaptic restructuring and neural plasticity may be related to the pathogenesis of several neuropsychiatric diseases, including mood disorders and schizophrenia. Disturbances in brain cellular function may alter concentrations of N-CAM in the CSF. Soluble human N-CAM proteins are detectable in the CSF but are minor constituents of serum. We have recently found an increase in N-CAM content in the CSF of patients with schizophrenia. Although the pathogenesis of both schizophrenia and mood disorders is unknown, ventriculomegaly, decreased temporal lobe volume, and subcortical structural abnormalities have been reported for both disorders. We have therefore measured N-CAM concentrations in the CSF of patients with mood disorder. There were significant increases in amounts of N-CAM immunoreactive proteins, primarily the 120-kDa band, in the CSF of psychiatric inpatients with bipolar mood disorder type I and recurrent unipolar major depression. There were no differences in bipolar mood disorder type II patients as compared with normals. There were no significant effects of medication treatment on N-CAM concentrations. It is possible that the 120-kDa N-CAM band present in the CSF is derived from CNS cells as a secreted soluble N-CAM isoform. Our results suggest the possibility of latent state-related disturbances in N-CAM cellular function, i.e., residue from a previous episode, or abnormal N-CAM turnover in the CNS of patients with mood disorder.

Adult