Lymphocyte function in major depressive disorder

Lymphocyte stimulation by phytohemagglutinin, concanavalin A, and pokeweed mitogen was significantly lower in a group of hospitalized depressed patients than in matched controls. The absolute number of T and B cells was lower in the depressed group, but the percentage of these cell types did not differ between the groups. These findings may be related to the altered neuroendocrine function found in patients with depressive disorders.

Apomorphine and schizophrenia. Treatment, CSF, and neuroendocrine responses

Previous studies have variably reported the efficacy of apomorphine in treatment of schizophrenia and tardive dyskinesia. Stimulation of dopamine neuron autoreceptors is the presumed mode of action. Low-dose apomorphine (0.75 mg subcutaneously) and placebo were administered to 25 male schizophrenics to evaluate the drug's effect on psychotic and tardive dyskinetic symptoms. No significant improvement or deterioration was seen. Concomitant measurements of plasma prolactin and growth hormone levels and CSF homovanillic acid level indicated that the dose used was centrally active. These results indicate that an active though nonsedating dose of apomorphine does not ameliorate symptoms of schizophrenia or tardive dyskinesia.

Possible clinical applications of laboratory tests in depression

The diagnosis of depression has traditionally been based on clinical history and behavioral observations. While objective laboratory tests will further our understanding of the pathophysiology and perhaps aid in the management of depression, a critical examination of the application of these techniques in clinical psychiatry is warranted by their increasing use. The utility for clinicians of the dexamethasone suppression test (DST), urinary MHPG assay, and tricyclic antidepressant plasma level assay is reviewed.

A family history study of schizophrenia-related personality disorders

This study examined whether the family history method can be used to detect cases of schizophrenia-related personality disorder in the families of schizophrenic patients. After proposing specific family history criteria for this diagnosis, the authors applied these criteria in a blind family history study and found that schizophrenia-related personality disorders were significantly more common in the first-degree relatives of schizophrenic patients than in the relatives of medically ill controls.

Genetic control of apomorphine-induced climbing behavior in two inbred mouse strains

Over a wide dose range (1-32 mg/kg), apomorphine-induced climbing behavior was significantly greater in the AKR/J than in the DBA/2J inbred mouse strain. A similar difference was found when apomorphine-induced stereotypy was examined. A cross-fostering study demonstrated that the strain difference in apomorphine-induced climbing behavior did not result from differences in post-natal rearing environment. After apomorphine administration, brain levels of the drug were similar in the two strains indicating that the difference in behavioral response to apomorphine in the two strains was not due to differences in metabolism or distribution of the drug. The climbing response to apomorphine was examined in the F1 cross of the two strains (AKD2F1/J) and in 10 AKXD recombinant inbred strains. Results suggested that the trait was partially dominant and not X-linked; furthermore, a few and possibly one locus was responsible for the differences in apomorphine-induced climbing behavior observed in the AKR/J and DBA/2J mice.

A study of the reliability of reported premorbid adjustment in schizophrenic patients

A study was conducted to determine the interrater reliability and the inter-informant reliability of two rating scales commonly used with schizophrenic patients. Both scales were completed by two informants for each of 45 schizophrenics. The Levels of Functioning Scale, which measures current social functioning, gave consistent results both between raters and between informants. The Premorbid Asocial Adjustment Scale, which measures social functioning during childhood and adolescence, produced very high reliability between raters but very poor reliability between informants. This suggests that much of the data collected about premorbid adjustment of schizophrenic patients are not accurate and that attempts to correlate reported premorbid adjustment with biological measures may be invalid. Ways of increasing the reliability and validity of premorbid adjustment measures are discussed.

Acetylcholinesterase activity in CSF in schizophrenia, depression, Alzheimer's disease and normals

Acetylcholinesterase (AChE) activity and protein were measured in the CSF of patients with Alzheimer's disease, depression, schizophrenia with and without tardive dyskinesia, and control subjects. AChE activity was assayed by a radioenzymatic method involving the direct extraction of hydrolyzed 3H-acetate into a toluene-based scintillation fluid followed by liquid scintillation spectrometry. AChE activity was proportional to the amount of CSF protein. Greater than 90% of AChE activity in CSF could be inhibited by 10(-3) M eserine. In addition, activity remained stable despite repeated freeze-thawing in an acetone-dry ice bath. Age was found to be positively correlated with CSF protein and AChE activity expressed per volume CSF, but not with AChE measured per milligram protein. No differences between diagnostic groups were found on either measure of AChE when the extraneous factors of age and CSF protein concentrations were controlled, nor were any differences found between groups for CSF protein when age was controlled.

Chronic administration of three neuroleptics: effects of behavioral supersensitivity mediated by two different brain regions in the rat

This investigation assessed the relative abilities of three neuroleptics to supersensitize behaviors mediated by the nigrostriatal and mesolimbic dopamine (DA) systems. Rats were treated with either haloperidol, thioridazine, fluotracen or vehicle for 21 days. Stereotypy, in response to DA injection to the striatum, or locomotor activity, in response to DA injection to the nucleus accumbens, were measured after the termination of drug treatment. Pre-treatment with haloperidol enhanced both behavioral responses to central DA injection, while pre-treatment with thioridazine did not enhance either behavior. Pre-treatment with fluotracen enhanced the locomotor response to DA injection to the nucleus accumbens, but did not alter stereotypy after DA injection to the striatum. Neuroleptics differ in their ability to supersensitize the same DA-related behavior, and act selectively to supersensitize behaviors mediated by different DA systems.

Gamma-hydroxybutyrate in the treatment of schizophrenia

Gamma-Hydroxybutyrate (GHB) inhibits firing of dopaminergic neurons and is thus potentially useful in the treatment of schizophrenia. GHB was administered to 10 schizophrenics concurrently with low-dose fluphenazine in a 6-week double-blind crossover study. No antipsychotic efficacy of GHB was noted. GHB had little if any effect on plasma prolactin levels after a single administration and caused few side effects. Trials with higher doses of GHB may be warranted.

Schizophrenia: a review of diagnostic and biological issues. II. Biological issues

Over the years schizophrenia has been the object of an extensive amount of research. In Part I of this paper, published in the April H&CP, the authors discussed research into diagnosis and prognosis. In particular, they outlined the studies that have been done on the major diagnostic systems, including the first-rank symptoms, the flexible system, the New Haven Schizophrenia Index, the Feighner criteria, the Research Diagnostic Criteria, and the Diagnostic and Statistical Manual of Mental Disorders, third edition. In part II they describe the literature on biological issues in schizophrenia. Included in their survey are the studies on neuropathological issues and on genetic and biological hypotheses of etiology and pathogenesis. In particular they discuss the possible roles of dopamine, endorphins and neuropeptides, endogenous psychotomimetics, and viruses in schizophrenia.

Neurotransmitter deficits in Alzheimer's disease: criteria for significance

A series of histopathologic, morphologic, and pharmacologic criteria are proposed to establish the significance of neurochemical deficits in Alzheimer's disease. The underlying pathogenic biochemistry of a better understood neurotransmitter-deficiency syndrome, Parkinson's disease, validates these criteria. The major neurotransmitter systems are evaluated against these guidelines. Only the cholinergic system fulfills all the criteria. Noradrenergic mechanisms are also implicated. Subsequent neurochemical abnormalities found in the brains of patients with Alzheimer's disease can be evaluated against these criteria.

Schizophrenia: a review of diagnostic and biological issues. I. Diagnosis and prognosis

Schizophrenia, a term that encompasses a diverse and seemingly unrelated class of psychopathologic conditions, has been the object of extensive research. This two-part paper reviews developments in specific areas of schizophrenia research. In Part I the authors discuss research into diagnosis and prognosis. They outline the studies that have been done on the major diagnostic systems including the first-rank symptoms, the flexible system, the New Haven Schizophrenia Index, the Feighner criteria, the Research Diagnostic Criteria, and the Diagnostic and Statistical Manual of Mental Disorders, third edition. They also report on the studies that have compared the utility and reliability of these diagnostic approaches. In Part II, to be published in the May issue, the authors cover the neuropathological studies of the disorder, the genetic research, and the various biological hypotheses of the etiology of schizophrenia.

The effects of diet and physical activity on plasma homovanillic acid in normal human subjects

This study examines the effect of diet and moderate physical activity on plasma levels of the dopamine metabolite homovanillic acid (HVA) in healthy young males. At weekly intervals, subjects were fed four isocaloric meals: polycose (pure carbohydrate), sustecal, low monoamine, and high monoamine. Moderate physical activity consisted of 30 minutes of exercise on a bicycle ergometer. The effect of diet on plasma HVA (pHVA) was highly significant. Compared to the polycose meal, the high monoamine meal significantly increased pHVA. Moderate physical activity also significantly increased pHVA. Future clinical studies using pHVA in man as an index of brain dopamine function should control for the effects of both diet and physical activity.

DST in depression is unaffected by altering the clock time of its administration

Circadian oscillators in major depressive illness may be phase advanced by several hours. We attempted to determine whether phase advance of the oscillator responsible for hypothalamic-pituitary-adrenal (HPA) function in depressives might influence the outcome of the overnight dexamethasone suppression test (DST). Six major depressives underwent DST with dexamethasone doses administered in a randomized fashion at 1900h and 2300h on separate evenings. Twenty-four hour cortisol secretory patterns basally and postdexamethasone were obtained for each subject. Postdexamethasone cortisol responses were similar for both the 1900h and 2300h dosage schedules in suppressors, nonsuppressors, and an early escape responder. We conclude that failure of the HPA axis to suppress normally with DST in major-depressive illness is a primary feature of neuroendocrine regulatory mechanisms rather than secondary to a posited phase advance of the related circadian oscillator.

Effects of propantheline bromide on basal growth hormone, cortisol and prolactin levels

Propantheline bromide, a peripheral anticholinergic drug with muscarinic and nicotinic blocking properties, was given by mouth to normal young men. Propantheline (45 mg) significantly lowered basal growth hormone concentrations at 0800 hr, 12 hr after administration. Propantheline (30 mg) tended (p = 0.08) to lower growth hormone concentrations at 1200 hr, 16 hr after administration. Cortisol and prolactin levels were not changed 12, 16 and 20 hr after propantheline (30 mg) nor 12 hr after propantheline (45 mg).

Enhancement of memory processes in Alzheimer's disease with multiple-dose intravenous physostigmine

Physostigmine (.125 mg, .25 mg, or .50 mg) or placebo was administered intravenously to 10 neuroleptic-free patients with Alzheimer's disease over a 30-minute period. All patients performed better on a recognition memory task while receiving physostigmine. When placebo or the dose of physostigmine previously associated with an improvement in memory was readministered, physostigmine again enhanced performance on a recognition memory task. These results indicate that the acute augmentation of cholinergic activity in some patients with Alzheimer's disease can partially reverse the memory deficit of that disorder and may provide an approach to the eventual therapy of this condition.

The neuropharmacology of tardive dyskinesia, spontaneous dyskinesia, and other dystonias

Most classifications of movement disorders emphasize their differential diagnosis and epidemiology according to clinical history and neurological examination. This review of movement disorders is organized according to the hypothesis of basal ganglia neurotransmitter imbalance in order to emphasize current research based on the pharmacology of these disorders. Specifically, dopamine (DA) excess and acetylcholine (ACh) deficiency may characterize part of the pathology of several hyperkinetic movement disorders including tardive dyskinesia, Huntington disease, Gilles de la Tourette syndrome, l-dopa dyskinesias, tardive Tourette syndrome, and toxic Tourette syndrome. The mirror image of this paradigm, namely DA deficiency and ACh excess, may characterize several rigid-dystonic movement disorders including Parkinson disease, drug-induced dystonias, and dystonia musculorum deformans. Finally, the unique combination of DA excess with ACh excess may characterize idiopathic orofacial dyskinesia (also known as Meige dystonia, Brueghel syndrome, and blepharospasm-oromandibular dystonia). Evidence supporting this formulation of movement disorders is reviewed, the limitations of this hypothesis are discussed, and new data from our own studies are presented.

The use of cholinergic precursors in neuropsychiatric diseases

Preclinical data suggest that cholinergic precursors such as choline or lecithin, increase levels of acetylcholine in specific brain structures, and under certain conditions may enhance cholinergic neurotransmission. A variety of neuropsychiatric diseases including tardive dyskinesia. Huntington's chorea, ataxias, Tourette's syndrome, schizophrenia, affective illness, and senile dementia of the Alzheimer type, has been implicated with a general underactivity of central cholinergic mechanisms. Recent studies have investigated the possibility that cholinergic precursor loading strategies may provide viable treatments for these disorders of presumed cholinergic underactivity. Extensive data demonstrate that the symptoms of tardive dyskinesia can be reduced by choline or lecithin, whereas investigations in other disorders have met with mild success, at best, or are still in preliminary stages. Further controlled studies with choline or lecithin using broader dose ranges, longer durations of treatment, and concomitant administration of agents which may increase the release of acetylcholine are warranted.

A signal detectability analysis of the effect of physostigmine on memory in patients with Alzheimer's disease

Ten patients with clinically diagnosed Alzheimer's disease were given tests of recognition memory while receiving placebo or physostigmine, a cholinesterase inhibitor, given intravenously over 30 min. Doses of 0.0, 0.125, 0.25, and 0.5 mg were given in random order on 4 separate days. All patients had their best performance following one of the doses of physostigmine rather than saline although dose-response curves varied from one patient to another. The dose associated with the best performance in each patient was compared with saline in a replication study using a double-blind cross-over design. In the replication study the total number of correct responses on the recognition memory task was significantly greater following physostigmine than following saline. To determine whether this improvement in performance was a result of an increase in the amount of information stored in memory or was secondary to a change in the patients' criteria for saying that they recognized an item, the results were subjected to a signal detectability analysis. This analysis indicated that studied items and new items were more discriminable following physostigmine, as evidenced by an increase in d', and that the criteria for saying which items had been studied also changed following physostigmine, as evidenced by an increase in C. The increase in d' indicates that physostigmine enhanced storage of information in memory while the change in C is consistent with the view that patients altered their decision criteria to maximize the number of correct responses in both conditions.

A rationale for studying the transmissibility of Alzheimer's disease

Despite extensive chemical, epidemiological, histopathological and pharmacological investigations of Alzheimer's disease (AD), its etiology remains elusive. This article describes studies supporting a rationale for exploring a transmissible slow viral etiology of at least some forms of AD. To date, a major limitation in these studies has been reliance upon induction of AD histopathology as the outcome measure of successful transmission. Future studies should consider novel outcome measures for the detection of successful, although histopathologically inapparent, transmissible infection. In addition, the need to inoculate a diverse variety of rationally selected, potential hosts is stressed.

Dopamine autoreceptor and postsynaptic receptor blocking potency of neuroleptics

Neuroleptic drugs have been shown to block brain dopamine (DA) receptors. The relative potency of neuroleptics at blocking DA postsynaptic receptors (PSRs) and autoreceptors (ARs) is less clear. To examine this question, the potency of 5 neuroleptics at inhibiting receptors (PSRs) and autoreceptors (ABs) is less clear. To examine this question, the potency of 5 neuroleptics at inhibiting the augmentation of mouse climbing behavior induced by a high dose of apomorphine (2.5 mg/kg) (presumably mediated by DA PSRs) was compared with their potency at inhibiting the suppression of climbing behavior induced by a low dose of apomorphine (0.45 mg/kg) (presumably mediated by DA Ars). Haloperidol and molindone had no AR-blocking ability even at doses that substantially blocked DA PSRs. Metoclopramide and fluphenazine had AR-blocking ability only at doses that produced substantial PSR blockade. Sulpiride blocked DA ARs at doses that had relatively litter PSR effect. It is concluded that neuroleptic drugs differ substantially in their relative potency at blocking DA ARs and PSRs.

Research subject recruitment for gerontological studies of pharmacological agents

Elderly subjects were recruited for a study of the effect of intravenous physostigmine on the memory disturbance of Alzheimer's Disease. Approximately one out of every twelve people screened was suitable for the study. Subjects were ruled out either because they did not meet research diagnostic criteria for AD, because they could not cooperate with the studies or because of medical contraindications. The data indicate that large numbers of potential subjects are required to select relatively small groups for pharmacological studies. The implications of some of these developments for future research are discussed.

Statistical power in biological psychiatry

The use of statistical power and power analysis in both the design and evaluation of experiments in biological psychiatry is described. The possible consequences of low power investigations are discussed, and guidelines are provided to facilitate the application of power analysis. Power curves are provided for sample sizes ranging from 10 to 100 for the Student's t test, and for testing the significance of an obtained Pearson correlation coefficient at both the 0.01 and 0.05 alpha levels. Additionally, difference scales are provided for plasma cortisol and for several neurotransmitter metabolites that are frequently measured in cerebrospinal fluid (CSF). Power evaluation of selected CSF studies measuring neurotransmitter metabolites in depressives and controls suggests the majority had less than a 50% chance of detecting a medium size difference before the experiment was actually performed.

Neuroendocrine and neurochemical measurements in depression

The authors performed dexamethasone suppression tests (DST), TRH infusions, 72-hour urine collections, and lumbar punctures on a group of male depressed patients. Approximately 60% of the patients were DST positive and 33% had a blunted TSH response. Two biologic variables, the 8 a.m. postdexamethasone cortisol and the postprobenecid CSF 5-hydroxyindoleacetic acid (5-HIAA), accounted for over half of the variance in the behavioral measure, the Hamilton score. Plasma cortisol elevation was associated with high 3-methoxy-4-hydroxyphenyl glycol (MHPG) excretion; TSH blunting was associated with low urinary MHPG excretion. Comprehensive biologic measures showed certain significant interrelationships and correlations with the severity of depression.

Lithium's effect of parathyroid hormone

Lithium has been reported to raise serum calcium and lower serum phosphate concentrations and to increase urinary calcium excretion. Because these changes may be effects of parathyroid hormone (PTH), PTH was measured in 19 patients receiving lithium. PTH was significantly higher in these patients than in 150 normal subjects. For all patients serum calcium concentrations correlated significantly with serum lithium concentrations. These results indicate that lithium may cause biochemical hyperparathyroidism. Secondary hyperparathyroidism in certain patients with lithium nephrotoxicity is also possible.

The genetics and biochemistry of paranoid schizophrenia and other paranoid psychoses

Genetic and biochemical findings in paranoid schizophrenia and other paranoid psychoses are reviewed. Although the data suggesting a lower genetic loading for schizophrenia in paranoid versus nonparanoid schizophrenia are unclear, paranoid schizophrenia does, to a limited extent, breed true within families. Monozygotic twins concordant for schizophrenia tend to be either both paranoid or both nonparanoid schizophrenics. In all studies, the risk for schizophrenia in the relatives of patients with paranoid psychosis is close to that found in the normal population. Genetic studies provide no evidence for a link between affective illness and either paranoid schizophrenia or paranoid psychosis. Although reports of low platelet monoamine oxidase activity in paranoid schizophrenia have not been confirmed, recent results suggest that brain norepinephrine levels may be higher in paranoid than in nonparanoid schizophrenics. Genetic and biochemical findings suggest some differences between paranoid and nonparanoid schizophrenia, but definitive clarification of the relationship between these two syndromes must await future research. From a genetic perspective, paranoid psychosis appears to bear little relationship to schizophrenia.

Alterations in cerebrospinal fluid dopamine metabolites following physostigmine infusion

The effect of IV physostigmine administration on the cerebrospinal fluid (CSF) levels of homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC) in normal subjects was determined. After an adjustment for differing CSF concentrations of probenecid, physostigmine was found to elevate CSF HVA and DOPAC concentrations. The authors discuss these changes in CSF HVA and DOPAC and their possible relationship to the ability of physostigmine to decrease the symptoms of some patients with tardive dyskinesia.

Subtypes of depression based on excretion of MHPG and response to nortriptyline

We investigated the relationship between urinary excretion of MHPG and the clinical response of 17 depressed patients to nortriptyline hydrochloride. Plasma concentrations of nortriptyline were monitored to assure optimal doses. Patients were classified as having "low" or "normal-high" excretion of MHPG based on one to five 24-hour urine specimens. Hamilton Depression Rating Scale scores were not reduced significantly more among the nine low excreters as compared with the eight normal-high excreters. However, when a true bimodal distribution of MHPG excretion was created by comparing only the six lowest excreters with the six highest excreters, the low group improved significantly more than the high group. This differential response to nortriptyline somewhat supports the notion that MHPG excretion may predict response to specific tricyclics. Collecting urine for MHPG determination in depressed patients is not easy; the variability of excretion within patients is considerable, and the range of MHPG excretion closely parallels that in normal persons. The clinical utility of this procedure is still to be determined.

MSH and MIF-I in animal models of tardive dyskinesia

alpha-Melanocyte stimulating hormone (MSH) and MSH release inhibiting factor (MIF-I) were tested for their effects on animals with prior exposure to haloperidol. Such animals are known to have an augmented sterotypic response to dopamine agonists and have been used as an animal model of tardive dyskinesia. Both MSH and MIF-I increased the stereotypy that followed the administration of the lowest dose of apomorphine (0.125 mg/kg), suggesting that MSH and MIF-I might weakly increase dopaminergic transmission.

beta-Endorphin and schizophrenia

To study the effects of beta-endorphin in chronic schizophrenia, nine male patients participated in a double-blind crossover comparison of a single intravenous 20-mg injection of beta-endorphin and saline. Bolus injection of beta-endorphin from an albumin-coated syringe produced markedly higher plasma concentrations than did slow intravenous infusion from a non-albumin-coated syringe. Beta-endorphin intravenously injected in nine patients produced a statistically significant increase in serum prolactin levels. In one patient, both 10 mg of morphine sulfate and 20 mg of beta-endorphin produced similar increases in the alpha power of the EEG. In eight patients, beta-endorphin administration was associated with a statistically significant but not clinically obvious improvement in schizophrenic symptoms.

Choline chloride effects on memory: correlation with the effects of physostigmine

Choline chloride (2g q.i.d.) and placebo were admin stered to nine young adults in a placebo-drug-placebo design. Subjects took memory tests at the end of both placebo periods and at the end of the choline period. All nine subjects had participated in a previous study in which 1.0 mg of physostigmine infused over a 1-hour period improved memory performance relative to performance during a saline infusion (Davis et al., 1978b). Choline had no significant efect on average performance either on a test of memory storage or on a test of memory retrieval. However, correlational analysis indicated that subjects who improved most when given physostigmine tended to show slight improvement when given choline. These results suggest that choline does not have substantial effects on memory but that there are small cognitive effects of choline in some subjects.

CKholinergic mechanisms and anterior pituitary hormone secretion

The study of the hypothalamic-pituitary axis has been a useful approach in assessing neurotransmitter function in man. Unfortunately, its utility in exploring cholinergic mechanisms is complicated by the induction of a stress response. However, the possibility that cholinergic transmission is a mediating factor in the stress response perhaps raises a more fundamental consideration.