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R M Post

Publications and source records attributed to R M Post.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Are convulsions necessary for the antidepressive effect of electroconvulsive therapy: outcome of repeated transcranial magnetic stimulation].

Sismotherapy (ST) brings about numerous neurobiological changes, particularly changes in neuromediators and their receptors, second messengers, neuropeptides and neurotropic factors, a number of which are hypothesized to play a role in the pathophysiology or therapeutics of affective disorders (M. Fink). What is not yet known is which of these mechanisms is crucial for the psychotropic and anticonvulsant effects of ST. However, it is clear that the effects of ST tend to be relatively acute, and do not attack the deep-seated abnormalities that are the underlying causes of recurrences of affective disorders. This is corroborated by the fact that in animals, most of the effects of ECS on catecholamines and their receptors (and on receptors for benzodiazepines or neuropeptides such as TRH) tend to be relatively transient, and in most cases have been found to represent compensatory adaptations to the induced motor convulsions. However, recent preclinical data using attenuation, and clinical findings using reiterated transcranial magnetic stimulation (rTMS), suggest that it may not be necessary to provoke a clonic convulsion in order to achieve the beneficial psychotropic and anticonvulsant effects of ST. In rodents receiving stimulation to the cerebellar tonsil, seven daily subacute low-frequency sessions (stimulation at 1 Hz for 15 minutes) produced clear improvement in clonic convulsions and in post-discharge thresholds, together with durable inhibition of convulsions when stimulation was resumed (Weiss et al., 1995). Stimulation at 1 Hz for 15 minutes was more effective than stimulation at 10 or 20 Hz in attenuating convulsions. Although reiterated ECS also induced an anti-triggering effect, this dissipated rapidly over five days (Post et al., 1984). It is of great interest that recent publications have shown that rTMS at 10 or 20 Hz to the left frontal cortex, administered to patients suffering from refractory depression (George et al., 1995) or to patients (hospitalised or not) with milder degrees of depression (Pasquale-Leon et al., 1996), had a moderate or marked antidepressant effect. In these studies, rTMS showed few unwanted effects (other than mild pain in some patients, due to contraction of the temporal muscles); it did not induce motor convulsions, and did not, as such, appear to be associated with the memory loss described in subjective accounts or in preliminary neuropsychological tests (Little and Kimbrell et al., 1996). The optimal frequencies, durations and positions for rTMS to maximise its antidepressant effect still remain to be determined. However, the first controlled and open studies have tended to show that (because of the capacity of rapid magnetic fluxes to produce sub-convulsant electrical discharges that are relatively localised in the brain), rTMS may be found to be a clinically useful antidepressant model. This would suggest the possibility that some of the neurochemical changes induced by the clonic convulsions of ECS could be directly induced by stimulation at the very edge of the threshold (but still below it); this would open up the hope that one day these endogenous neurochemical processes could be identified and exploited in an optimal way for therapeutic purposes.

Brain↗
PubMed1997

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↗
PubMed1997

Psychosensory symptoms in bipolar disorder.

This study investigated psychosensory symptoms and their relationship to retrospective and prospective courses of illness, as well as therapeutic outcomes, in patients with bipolar disorder. Using the Silberman-Post Psychosensory Rating Scale (SP-PSRS), psychosensory symptoms were assessed in 51 patients who met Diagnostic and Statistical Manual, 3rd Edition-Revised (DSM-III-R) criteria for bipolar disorder and in 39 healthy, normal controls. Patients with bipolar disorder were enrolled in a 3-year, double-blind, randomized study comparing the prophylactic efficacy of lithium or carbamazepine in the first year, a crossover to the other drug in the second year, and the combination of both medications in the third year. Psychosensory scores from patients with bipolar disorder were compared with scores from healthy controls and with a variety of retrospective and prospective course of illness and treatment variables. Psychosensory symptoms occurred frequently in patients with bipolar I and II disorders, but were rare in healthy controls. When depressed, patients with bipolar II disorder (n = 23) reported more psychosensory symptoms when compared to patients with bipolar I disorder (n = 28), and those with a history of rapid cycling (n = 29) reported more psychosensory symptoms when compared to patients without a history of rapid cycling (n = 21). Psychosensory symptoms were not related to response to carbamazepine, lithium, or the combination of both drugs. Although the presence of psychosensory symptoms is associated with some bipolar subtypes (patients with bipolar II disorder and patients with a history of rapid cycling), they do not appear to predict treatment response. Further studies are needed to assess the pathophysiologic implications of the presence of psychosensory symptoms and their potential implications, if any, for directing therapeutics.

Adult↗
PubMed1996

Gender differences in regional cerebral blood flow during transient self-induced sadness or happiness.

Men, compared to women, are less likely to experience mood disorders. We wondered if gender differences exist in the ability to self-induce transient sadness and happiness, and in regional cerebral blood flow (rCBF) either at rest or during transient emotions. Ten adult men and 10 age-matched women, all healthy and never mentally ill, were scanned using H2(15)O positron emission tomography at rest and during happy, sad, and neutral states self-induced by recalling affect-appropriate life events and looking at happy, sad, or neutral human faces. At rest, women had decreased temporal and prefrontal cortex rCBF, and increased brainstem rCBF. There were no significant between-group differences in difficulty, effort required, or the degree of happiness or sadness induced. Women activated a significantly wider portion of their limbic system than did men during transient sadness, despite similar self-reported changes in mood. These findings may aid in understanding gender differences with respect to emotion and mood.

Adult↗
PubMed1996

Understanding emotional prosody activates right hemisphere regions.

BACKGROUND: Defects in expressing or understanding the affective or emotional tone of speech (aprosodias) have been associated with right hemisphere dysfunction, while defects of propositional language have been linked to left hemisphere disease. The brain regions involved in recognition of emotional prosody in healthy subjects is less clear. OBJECTIVES: To investigate the brain regions involved in understanding emotional prosody and to determine whether these differ from those involved in understanding emotion based on propositional content. METHODS: We studied 13 healthy subjects using water labeled with radioactive oxygen 15 and positron emission tomography while they listened to 3 similar sets of spoken English sentences. In different tasks, their responses were based on the emotional propositional content, on the emotional intonation of the sentence (prosody), or on their ability to repeat the second word in the sentence (control). RESULTS: Understanding propositional content activated the prefrontal cortex bilaterally, on the left more than on the right. In contrast, responding to the emotional prosody activated the right prefrontal cortex. CONCLUSION: Neurologically healthy subjects activate right hemisphere regions during emotional prosody recognition.

Adult↗
PubMed1996

Anterior paralimbic mediation of procaine-induced emotional and psychosensory experiences.

BACKGROUND: Procaine activates limbic structures in animals. In humans, acute intravenous administration of procaine yields emotional and psychosensory experiences and temporal lobe fast activity. We studied procaine's acute effects on cerebral blood flow (CBF) in relationship to clinical responses. METHODS: Cerebral blood flow was assessed by positron emission tomography with oxygen-15-labeled water in 32 healthy volunteers. Data were analyzed with statistical parametric mapping and magnetic resonance imaging-directed regions of interest. RESULTS: Procaine increased global CBF and, to a greater extent, anterior paralimbic CBF. Subjects with intense procaine-induced fear compared with those with euphoria had greater increases in left amygdalar CBF. Absolute and normalized left amygdalar CBF changes tended to correlate positively with fear and negatively with euphoria intensity. Procaine-induced visual hallucinations appeared associated with greater global and occipital CBF increases. Absolute occipital CBF increases appeared to correlate positively with visual hallucination intensity. CONCLUSIONS: Procaine increased anterior paralimbic CBF, and different clinical responses appeared to be associated with different patterns of CBF changes.

Adolescent↗
PubMed1996

A speculative model of affective illness cyclicity based on patterns of drug tolerance observed in amygdala-kindled seizures.

In this article, we discuss molecular mechanisms involved in the evolution of amygdala kindling and the episodic loss of response to pharmacological treatments during tolerance development. These phenomena allow us to consider how similar principles (in different neurochemical systems) could account for illness progression, cyclicity, and drug tolerance in affective disorders. We describe the phenomenon of amygdala-kindled seizures episodically breaking through effective daily pharmacotherapy with carbamazepine and valproate, suggesting that these observations could reflect the balance of pathological vs compensatory illness-induced changes in gene expression. Under certain circumstances, amygdala-kindled animals that were initially drug responsive can develop highly individualized patterns of seizure breakthroughs progressing toward a complete loss of drug efficacy. This initial drug efficacy may reflect the combination of drug-related exogenous neurochemical mechanisms and illness-induced endogenous compensatory mechanisms. However, we postulate that when seizures are inhibited, the endogenous illness-induced adaptations dissipate (the "time-off seizure" effect), leading to the re-emergence of seizures, a re-induction of a new, but diminished, set of endogenous compensatory mechanisms, and a temporary period of renewed drug efficacy. As this pattern repeats, an intermittent or cyclic response to the anticonvulsant treatment emerges, leading toward complete drug tolerance. We also postulate that the cyclic pattern accelerates over time because of both the failure of robust illness-induced endogenous adaptations to emerge and the progression in pathophysiological mechanisms (mediated by long-lasting changes in gene expression and their downstream consequences) as a result of repeated occurrences of seizures. In this seizure model, this pattern can be inhibited and drug responsivity can be temporarily reinstated by several manipulations, including lowering illness drive (decreasing the stimulation current), increasing drug dosage, switching to a new drug that does not show crosstolerance to the original medication, or temporarily discontinuing treatment, allowing the illness to re-emerge in an unmedicated animal. Each of these variables is discussed in relation to the potential relevance to the emergence, progression, and suppression of individual patterns of episodic cyclicity in the recurrent affective disorders. A variety of clinical studies are outlined that specifically test the hypotheses derived from this formulation. Data from animal studies suggest that illness cyclicity can develop from the relative ratio between primary pathological processes and secondary endogenous adaptations (assisted by exogenous medications). If this proposition is verified, it further suggests that illness cyclicity is inherent to the neurobiological processes of episode emergence and amelioration, and one does not need to postulate a separate defect in the biological clock. The formulation predicts that early and aggressive long-term interventions may be optimal in order to prevent illness emergence and progression and its associated accumulating neurobiological vulnerability factors.

Affect↗
PubMed1996

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↗
PubMed1996

Changes in cholecystokinin mRNA expression after amygdala kindled seizures: an in situ hybridization study.

Cholecystokinin (CCK) can be a potent anticonvulsant neuropeptide in certain seizure models. Therefore, we examined whether seizures produced by electrical kindling of the amygdala or electroconvulsive seizures (ECS) would affect the expression of CCK mRNA in rat brain. Following a single kindled seizure, CCK mRNA expression was decreased about 20-58% in the amygdala. In contrast, after multiple consecutive kindled seizures, CCK mRNA expression was increased in the amygdala, cerebral cortex, CA1 pyramidal cell layer of the hippocampus and dentate hilus. A single ECS produced no effect on CCK mRNA expression, but multiple ECS increased expression in the interneurons of the hippocampus 24 h after the last seizure. Since seizures produced by ECS can be anticonvulsant to further ECS or kindled seizures, the CCK increases in the hippocampus may represent a compensatory anticonvulsant adaptation observed in both models. Overall, the kindling-induced alterations in CCK expression appear to be more complex involving multiple brain regions and distinct temporal properties.

Amygdala↗
PubMed1996

Felbamate monotherapy has stimulant-like effects in patients with epilepsy.

The objective of this study was to assess the psychiatric effects of the antiepileptic drug (AED) felbamate (FBM) in patients with epilepsy. FBM is a new AED with a novel putative (antiglutaminergic) mechanism. Older AEDs such as carbamazepine and valproate have psychotropic properties, but the psychiatric effects of FBM and other new antiglutamatergic AEDs remain to be determined. Thirty inpatients with refractory epilepsy were openly tapered off all AEDs in conjunction with intensive presurgical monitoring prior to a two week randomized double-blind parallel trial of FBM monotherapy versus placebo, followed by open FBM therapy. Psychopathology was rated with weekly psychiatric rating scales. Anxiety, depression and seizures increased significantly with AED discontinuation. Acute blind FBM monotherapy yielded antiepileptic and stimulant-like effects (insomnia, anorexia, and anxiety), but failed to influence AED withdrawal-emergent psychopathology. Restarting original AEDs resolved such pathology in FBM drop outs. Chronic open FBM also had stimulant-like effects, with half of the patients displaying psychiatric deterioration and the other half modest improvement compared to baseline therapies. Baseline insomnia and anxiety may be markers for poorer psychiatric responses to chronic open FBM. FBM had stimulant-like effects, lacked anxiolytic effects, and failed to attenuate AED withdrawal-emergent psychopathology. Baseline insomnia or anxiety may predict poorer psychiatric responses to FBM. Further studies are required to assess whether the novel psychiatric effects observed with FBM also occur with other new antiglutamatergic AEDs.

Adult↗
PubMed1996

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↗
PubMed1996

Differential regulation of basal and kindling-induced TRH mRNA expression by thyroid hormone in the hypothalamic and limbic structures.

It has previously been demonstrated that thyrotropin-releasing hormone (TRH) mRNA expression is dramatically increased in limbic structures including dentate gyrus granular layer, and pyriform, entorhinal and perirhinal cortices following amygdala kindling. Since thyroid hormone regulates TRH mRNA in the paraventricular nucleus of the hypothalamus (PVN), we investigated whether basal or kindling-induced TRH mRNA expression in limbic regions is also regulated by thyroid hormone. Hypo- and hyperthyroidism was induced by treating rats with 0.05% 6-n-propyl-2-thiouracil (PTU) (equivalent to approximately 30 mg/kg/day) or 0.9 microM 3,5,3'-triiodo-L-thyronine (T3) (equivalent to approximately 50 micrograms/kg/day), respectively, in their drinking water for 10 days before kindling and throughout the kindling procedure. Rats were sacrificed 4 h after their first stage 5 seizure. None of the thyroid hormone manipulations altered kindling development, or behavioral and electrographic after-discharge seizure durations. Pituitary TSH beta mRNA levels were significantly increased by PTU and suppressed by T3, but unaffected by kindling. In addition, in situ hybridization showed that PTU administration increased and T3 administration decreased TRH mRNA levels in the PVN, consistent with thyroid hormone's negative feedback effects. At the same time, kindling had no effect on TRH mRNA in the PVN. In contrast, kindling dramatically increased TRH mRNA in the dentate gyrus granular layer, and pyriform, entorhinal and perirhinal cortices, but thyroid hormone manipulations did not affect either basal or kindling-induced TRH mRNA expression in limbic structures. These findings demonstrate that TRH mRNA expression is differentially regulated in the hypothalamic PVN and limbic structures.

Amygdala↗
PubMed1996

Changes in mood and hormone levels after rapid-rate transcranial magnetic stimulation (rTMS) of the prefrontal cortex.

Rapid-rate transcranial magnetic stimulation (rTMS) was administered to 10 healthy volunteers on different days over the right or left prefrontal cortex, midfrontal cortex, occipital cortex, or cerebellum. Mood (self-rated), reaction time, and hormone levels were serially measured. Consistent with a previous study, comparison of hemispheres revealed significant associations with decreased happiness after left prefrontal rTMS and decreased sadness after right prefrontal rTMS. Stimulation of all three prefrontal regions, but not the occipital or cerebellar regions, was associated with increases in serum thyroid-stimulating hormone. There was no effect on serum prolactin. rTMS applied to prefrontal cortex is safe and well tolerated and produces regionally and laterally specific changes in mood and neuroendocrine measures in healthy adults. rTMS is a promising tool for investigating prefrontal cortex functions.

Adult↗
PubMed1996

Transcranial magnetic stimulation: a neuropsychiatric tool for the 21st century.

Neuroscientists have constantly sought new methods of evaluating brain function, with progressive improvement in the last century in imaging brain structure and function. However, except for direct surgical stimulation, neuropsychiatrists can only infer causality between the signal obtained on an image and a behavior or disease. Transcranial magnetic stimulation (TMS) is a new, noninvasive technique for directly stimulating cortical neurons. It has been used to map attention, memory, movement, speech, and vision. Preliminary investigations have also used rapid-rate TMS to improve motor speed in Parkinson's disease and mood in depression. TMS is likely to be an important future neuropsychiatric tool.

Anxiety Disorders↗
PubMed1996

Ultra-rapid and ultradian cycling in bipolar affective illness.

BACKGROUND: Rapid-cycling bipolar disorder is defined as four or more affective episodes yearly. The conventionally recognised limit in episode duration is usually considered 24 hours (i.e. a cycle duration of 48 hours). We report a small series of intensively observed bipolar patients who showed much faster patterns of mood oscillation. METHODS: Detailed, systematic, longitudinal assessment of five bipolar patients during extended in-patient psychiatric evaluation were conducted, including retrospective life charting and prospective evaluation of daily mood by self and blinded observer ratings, and motor activity recording. RESULTS: Our data demonstrate a spectrum of cycling frequencies in rapid-cyclers, including distinct, clinically robust mood shifts that occur at frequencies faster than once per 24 hours. Affective oscillations spanned a range of cycling frequencies from four episodes per year (rapid cycling) to those occurring within the course of weeks to several days (ultra-rapid cycling), to distinct, abrupt mood shifts of less than 24 hours duration (ultra-ultra rapid or ultradian cycling). The time of onset and duration of these ultradian affective fluctuations are highly variable and they are observed in bipolar patients without evidence of personality disorder. CONCLUSIONS: The potential clinical and theoretical implications of these first systematic observations of ultra-rapid and ultradian cycling in the context of the evolution of otherwise classical bipolar affective illness are discussed.

Adult↗
PubMed1996

Venlafaxine or bupropion responders but not nonresponders show baseline prefrontal and paralimbic hypometabolism compared with controls.

In this study, 11 unipolar depressed outpatients received baseline (medication-free) fluorine-18 deoxyglucose positron emission tomography scans prior to randomization to double-blind venlafaxine or bupropion monotherapy, with the option of a subsequent medication crossover. Based on Clinical Global impressions ratings, 6 of 11 responded to at least one medication. Regional cerebral glucose metabolic rate (rCMRglu) for these 6 responders was compared with 18 age- and gender-matched healthy controls; the 5 nonresponders were compared with 15 matched healthy controls. Compared with healthy controls, responders showed decreased (normalized > absolute) left middle frontal gyral, bilateral medial prefrontal, and bilateral temporal rCMRglu. In contrast, nonresponders showed decreased (normalized > absolute) cerebellar rCMRglu. These preliminary data suggest that among never-hospitalized unipolar depressed out-patients, those showing baseline prefrontal and paralimbic hypometabolism may be more likely to show a positive response to standard antidepressant treatments such as venlafaxine or bupropion.

Adult↗
PubMed1996

Rational polypharmacy in the bipolar affective disorders.

Bipolar affective illness represents a syndrome not readily treated by single agents. Approximately 50% of patients are inadequately responsive to lithium and the majority of patients require supplemental antidepressants, antimanic, antipsychotic or hypnotic medications. These traditional adjunctive medications are associated with potential problems. Antidepressants may precipitate mania (at a rate about double that of placebo) or cause cycle acceleration. Neuroleptics may be associated with either more profound or longer depressive phases, and clearly increase the risk of tardive dyskinesia, to which bipolar patients appear particularly predisposed. Moreover, there are subgroups of patients who are known to be poorly responsive to lithium. These include patients with rapid cycling, dysphoric mania, co-morbid drug or alcohol abuse, a pattern of depression-mania-well interval (D-M-I as opposed to the M-D-I pattern), and patients without a family history of bipolar illness in first-degree relatives. There is increasing recognition that the anticonvulsants carbamazepine and valproate are effective alternatives or adjuncts to lithium in the acute and long-term treatment of bipolar illness. Ideally, one would want to assess whether patients who were unresponsive to lithium were responsive to an anticonvulsant alone prior to utilizing lithium in addition to anticonvulsant combination therapy. However, from the clinical perspective, it is often more expedient to use an anticonvulsant adjunctively to lithium to assess the efficacy of this combination and establish mood stabilization. When lithium is not discontinued, the increased morbidity during lithium withdrawal also would not occur and would not confound the evaluation of the new agent. We suggest the initial use of acute adjuncts to lithium with the anticonvulsants carbamazepine or valproate (instead of neuroleptics) so that their efficacy can be assessed in the individual's acute episode, with the likelihood of a positive response in longer-term prophylaxis. Hypnotic benzodiazepines with anticonvulsant properties, such as clonazepam or lorazepam, are often used to help to induce sleep in escalating bipolar patients, and may be useful adjuncts as well. Patients who were inadequately responsive to either carbamazepine or valproate alone may be responsive to the anticonvulsant combination. In a similar fashion, one can also utilize several mood-stabilizing drugs (lithium and an anticonvulsant such as carbamazepine or valproate) in the treatment of depressive breakthroughs, and then augment this combination (if necessary) with a catecholamine-active antidepressant such as bupropion or a serotonin-selective reuptake inhibitor (SSRI) such as fluoxetine, paroxetine, sertraline or if necessary a monoamine oxidase inhibitor (MAOI). Once the patient has responded to a combination of drugs, it becomes problematic to decide whether the last agent added was the crucial ingredient in helping the patient achieve remission or that remission might have occurred with this agent alone. A conservative approach would have merit in patients who are finally stabilized on complex polypharmacy regimens only after many years of sequential trials; in this instance, the potential risk of re-exacerbating the illness with a taper of one of the drugs in the regimen. Rational polypharmacy should thus be implemented with careful delineation of the prior course of illness (typically using life chart methodology) and targeted treatment outcomes titrated against side effects, using sequential clinical trials in individual patients who have not adequately responded to monotherapy. In this fashion, it is hoped that pharmacodynamic differences among agents can be maximized and pharmacokinetic and side effects minimized.

Anticonvulsants↗