CNS adrenergic receptors and beta blockade

The changes in noradrenergic and adrenergic activity that regulate beta-adrenergic receptors in the CNS have been assessed by lesion studies as well as by pharmacologic enhancement and inhibition of transmission. Beta-adrenergic receptor subtypes are differentially distributed throughout the CNS and are probably differentially regulated. An effect of normal aging on beta receptors has been found in studies of both animal and human brain tissue. Preliminary studies relating to neuropsychiatric disorders in humans and animal studies on the action of antidepressants suggest that CNS beta receptors may play a critical role in affective disorders and their treatment. This may explain why beta-blocker medication is associated with side effects such as depression and lethargy, which are generally reversible when selective hydrophilic beta blockers are used or when the therapy is withdrawn.

Adrenocortical hyperactivity in depression: effects of agitation, delusions, melancholia, and other illness variables

In an attempt to determine the relative contributions to adrenocortical hyperactivity in depression of agitation, delusions, and melancholic subtype, we measured cortisol levels before and after dexamethasone in 93 unipolar major depressed inpatients. Stepwise multiple regression showed that agitation predicted 22% of the variance in a.m. cortisol level after dexamethasone. Addition of the variables melancholia and delusionality to the regression model accounted for 27% and 34%, respectively, of the variance in the same cortisol variable. Age, illness severity, and weight loss added no further significant predictive value. Age, weight loss, and illness severity did affect cortisol levels when examined separately from the other variables. Rate of nonsuppression on the dexamethasone suppression test (DST) differed between the nonmelancholic major depressive group and any other group with melancholia. These results suggest why some discrepancies may exist between studies of the DST in delusional depression and indicate that agitation merits careful assessment in future studies of DST response.

Psychobiologic predictors of suicide

Suicide is a significant cause of mortality in patients suffering from major affective disorders, schizophrenia, and alcoholism. Generally, several clinical and psychosocial factors combine to result in suicide. These risk factors have high sensitivity but low specificity; only a small minority of patients who meet risk criteria actually complete suicide. Therefore, clinicians have had great difficulty in assessing suicide risk; more clinically useful risk indicators are crucially needed. Biologic markers such as low cerebrospinal fluid levels of the serotonin metabolite 5-hydroxyindoleacetic acid and related indices of serotonergic function appear to correlate with violent and impulsive suicidal behavior. These and other biologic changes may have predictive value in determining suicide risk, as well as contributing to the formulation of a more complete model to explain suicidal behavior that combines genetic, biologic, psychologic, and social factors.

Clinical nonrecognition of neuroleptic-induced movement disorders: a cautionary study

Extrapyramidal side effects are a major limitation in the use of neuroleptics, and tardive dyskinesia is a special public health problem. Accurate clinical diagnosis of extrapyramidal syndromes is necessary for effective management. The authors compared clinicians' recognition of the major extrapyramidal syndromes in 48 psychotic inpatients with independent blind diagnoses by clinical researchers using standardized ratings. The major finding was a high rate of clinical underrecognition of all major extrapyramidal syndromes, especially tardive dyskinesia. The authors discuss the clinical predictors of nonrecognition of extrapyramidal side effects and recommend improved training in their detection.

Reduced length and cost of hospital stay for major depression in patients treated with ECT

To investigate the effect of treatment modality on length of hospital stay, the authors retrospectively studied 86 admissions of 74 patients with major depression. All 19 patients who received ECT recovered, in contrast to only 27 (49%) of 55 patients given tricyclic antidepressants or other medication. The 28 patients who had not responded to antidepressants recovered after treatment with ECT. Treatment modality had a highly significant effect on length of hospital stay: patients given ECT stayed a mean of 13 fewer days, saving more than $6,400 per patient at current rates. These findings of significant economic and therapeutic benefits in the use of ECT raise issues about treatment selection for depressed inpatients.

Assessment of binding indices and physiological responsiveness of the 5-HT2 receptor on human platelets

This is the first report of parallel studies of binding indices and physiological responsiveness of the "Serotonin-two" (5-HT2) receptor on the human platelet membrane. Binding indices were measured by a microassay employing [125I]ILSD as radioligand and ketanserin to define specific binding. A single receptor population was found, characterized by a KD of 1.69 +/- 0.45 nM and Bmax of 14.5 +/- 6.0 pmol/g protein in healthy subjects. Functional responsiveness of the platelet 5-HT2 receptor complex was assessed by measurement of the extent to which serotonin (10uM) augmented platelet aggregation induced by threshold concentrations of adenosine diphosphate (ADP). A statistically significant positive correlation was found between the number of platelet 5-HT2 receptor sites (Bmax) and the magnitude of the serotonin-amplified aggregation response (r = .70, n = 38, p less than 0.001). Assessment of binding indices and physiological responsiveness of the platelet 5-HT2 receptor complex should facilitate study of age, hormonal, disease, and drug effects on 5-HT2 receptor function in human subjects.

Cardiac rate and rhythm in panic patients

This study assessed cardiac rate and rhythm by ambulatory monitoring in 23 patients with panic disorder or agoraphobia with panic attacks. The patients had a higher than normal mean daily density of ventricular premature complexes (VPCs), but complex ventricular arrhythmias were uncommon. Heart rate was greater during panic intervals than during asymptomatic periods. The prevalence of arrhythmias within symptomatic intervals was similar during panic, partial panic, and anxiety and was significantly higher than during asymptomatic intervals. However, most panic episodes had no arrhythmias, and arrhythmias during panic intervals were simple VPCs.

Clonidine binds to imidazole binding sites as well as alpha 2-adrenoceptors in the ventrolateral medulla

Binding sites labeled by [3H]p-aminoclonidine ([3H]PAC) were characterized in bovine brain membranes prepared from the ventrolateral medulla, the probable site of the antihypertensive action of clonidine and analogs. Comparison was made with [3H]PAC binding to membranes prepared from frontal cortex, which has been studied extensively. Saturation binding isotherms for [3H]PAC were similar in the two regions, although Bmax values were approximately two-fold lower in ventrolateral medulla relative to frontal cortex. Norepinephrine and other phenylethylamines displaced [3H]PAC from a maximum of 70% of the total sites in the ventrolateral medulla. The remaining 30% were norepinephrine-insensitive, non-adrenoceptor sites which displayed high affinity for imidazole compounds. Ligand selectivity differed markedly between ventrolateral medulla and frontal cortex, since some imidazole compounds which potently inhibited [3H]PAC binding in the ventrolateral medulla had no effect in frontal cortex. Imidazole binding sites may mediate, in part, the hypotensive action of clonidine and other imidazole compounds in the ventrolateral medulla. These sites may also participate in the functions of a putative endogenous clonidine-like substance.

Increased serotonin2 and beta-adrenergic receptor binding in the frontal cortices of suicide victims

A statistically significant 28% increase in the mean (+/- SD) number of serotonin2 receptors (127.8 +/- 13.4 vs 99.6 +/- 11.1 fmol/mg of protein) and a 73% increase in beta-adrenergic receptor binding (14.5 +/- 1.5 vs 8.4 +/- 1.5 fmol/mg) was found in the frontal cortices of violent suicide victims compared with matched controls. No significant differences were found in the number of serotonin1 binding sites (109.5 +/- 13.4 vs 99.9 +/- 8.8 fmol/mg). We have previously reported a reduced density of presynaptic tritiated imipramine binding sites on serotonergic nerve terminals in the frontal cortices of suicide victims. These data support the hypothesis that suicide completed by violent methods is associated with reduced presynaptic serotonergic activity that has generated compensatory upregulation of the postsynaptic serotonin2 receptor sites. The increase observed in beta-adrenergic binding suggests that there may also be a concomitant reduction in presynaptic noradrenergic activity associated with suicide. If antidepressant pharmacotherapies specifically downregulate cortical beta-adrenergic and/or serotonin2 receptors in depressed subjects, as has been demonstrated in animal studies, and since these effects would be in the opposite direction of the receptor changes found in suicide victims, they may account for the therapeutic action of antidepressants on suicidal behavior and depressive disorders.

Elevated postmortem monoamine oxidase B activity in the caudate nucleus in Huntington's disease compared to schizophrenics and controls

Activity (Vmax) of monoamine oxidase (MAO) B in necropsy samples from the head of the caudate nucleus was 260% higher in patients dying with Huntington's disease (HD) than in controls (P less than 0.05). No differences in MAO A enzyme kinetics were found. MAO B, but not MAO A, was increased (26%) in the frontal cortex from patients dying with HD compared to control subjects. MAO A and B kinetics in caudate nucleus and frontal cortex from a group of schizophrenics did not differ from controls. Postmortem delay, the effect of neuroleptics, or nonspecific degeneration artifacts did not explain these findings. It is suggested that the increase in MAO B activity in the caudate nucleus may reflect neurochemical changes that are responsible for the choreiform movements of Huntington's disease. Lower cortical MAO B activity in the schizophrenic group may reflect the effects of neuroleptics.

Effects of lithium carbonate on associative productivity and idiosyncrasy in bipolar outpatients

To determine the effect of lithium carbonate on the productivity and idiosyncrasy of written associations of euthymic outpatients with affective disorder, the authors assessed 22 patients at weekly intervals during lithium treatment, 2 consecutive weeks of placebo, and 2 consecutive weeks after lithium was resumed. Lithium discontinuation produced a significant increase in associational productivity and a demonstrable increase in associative idiosyncrasy, and restoration of lithium dose significantly reversed both effects. The results suggest that lithium may affect the underlying neuropsychological functions critical to the ability to generate associations and indicate the need for further study of lithium's effects on these and other functions that may relate to neuropsychological and creative processes.

Adrenocortical function and suicidal behavior in depressive disorders

In order to examine the hypothesis that abnormal adrenocortical function is associated with suicidal behavior, morning and afternoon plasma cortisols and 1-mg dexamethasone suppression tests (DSTs) were performed in 65 patients with primary major depressive disorder. Patients with recent suicide attempts (within 28 days before DST) were compared to patients who had made past attempts and those who had never made suicide attempts with respect to age, gender, severity of depression, and plasma cortisol levels. Plasma cortisol levels did not differ significantly among the three groups. Nonsuppression on the DST was associated with presence of delusions, increasing age, and global severity of depression, but not with suicide attempts.

Reduced sensitivity of lymphocyte beta-adrenergic receptors in patients with endogenous depression and psychomotor agitation

It has been suggested that there are altered levels of norepinephrine or other neurotransmitters at functionally important receptors in patients with depressive disorders. This hypothesis is difficult to study in the human central nervous system. However, noradrenergic function can be assessed indirectly with peripheral-blood lymphocytes used as a model of the beta-adrenergic receptor complex. We found that drug-free inpatients with endogenous depression had lower isoproterenol-stimulated cyclic AMP levels in intact lymphocytes than did healthy control subjects (3.9 +/- 0.5 vs. 7.4 +/- 1.0 pmol per 10(6) cells, P less than 0.01). The density and affinity of beta-adrenergic receptors were similar in controls and depressed subjects (beta-receptor number, 5.4 +/- 0.7 and 5.3 +/- 0.8 fmol per 10(6) cells; binding affinity, 106 +/- 7.6 vs. 99.2 +/- 11.4 pM, respectively). When the depressed patients were subdivided by psychomotor manifestations, binding characteristics were indistinguishable among the subgroups. However, a significant reduction in beta-adrenergic responsiveness was observed in patients with psychomotor agitation, as compared with controls (2.6 +/- 0.5 vs. 7.4 +/- 1.0 pmol per 10(6) cells, P less than 0.01), but not in patients with psychomotor retardation (5.8 +/- 1.1 pmol per 10(6) cells, P less than 0.05). Thus, the desensitization of beta-adrenergic receptors was correlated more closely with the severity of psychomotor agitation than with the overall severity of depression.

Comparison of injectable molindone and haloperidol followed by oral dosage forms in acutely ill schizophrenics

The comparative efficacy of molindone and haloperidol, given by injection for the first 2-3 days of hospitalization and then continued orally for up to 4 weeks, is reported from an ongoing double-blind study. Efficacy and side effects were assessed by the Brief Psychiatric Rating Scale, Clinical Global Impressions, Treatment Emergent Symptom Scale, and Target Symptom Ratings. Analyses based on the first 35 patients who entered the study indicate that both drugs were effective and well tolerated. There were slight advantages for molindone early during the injectable phase of treatment and for haloperidol late during the oral portion of the study, but these differences were not clinically significant. No significant differences in side effects were found between the two drugs.

Peripheral edema associated with trazodone: a report of ten cases

Ten depressed patients treated with trazodone developed edema and weight gain that was promptly reversed by reduction or discontinuation of trazodone. This suggests a dose-dependent effect. None of the patients had an active medical problem that might predispose to edema formation. Summary data on all 10 cases and three case histories are presented to alert physicians to this side effect.

Atypical depression: a review of diagnosis and treatment

The diagnosis of atypical depression has been used in a variety of ways in the psychiatric literature. The authors review the different uses of the term and then examine the syndrome's capacity to reliably predict course of illness, family prevalence, biological test date, and response to treatment. They conclude that as a diagnosis, atypical depression is misleading and does not describe a discrete or homogeneous group of patients. However, the literature on atypical depression has been extremely important in identifying patients for whom pharmacological intervention may be of great benefit and for whom it has been underutilized in the past.

A clinical perspective on the role of neurotransmitters in mental disorders

The authors first review the mechanisms of neural transmission. They then provide a detailed discussion of norepinephrine, dopamine, and serotonin--the three neurotransmitters that have been implicated most often in etiological studies of affective disorders and schizophrenia. After outlining the synthesis, location, and pharmacological response of these transmitters, the authors consider the role of neurotransmission in the theoretical models of depression and schizophrenia.