Studies of amphetamine or methamphetamine psychosis in Japan: relation of methamphetamine psychosis to schizophrenia

There exist clinical characteristics of methamphetamine (MAP) psychosis in the Japanese population. MAP psychosis involves paranoid-hallucinatory states indistinguishable from paranoid schizophrenia, with residual volitional disturbances (e.g., loss of spontaneity and idleness). Paranoid-hallucinatory states persist after the pharmacological effects of MAP have worn off and readily reappear upon a reinjection of MAP. Individuals with a history of MAP psychosis further undergo spontaneous recurrence of their paranoid-hallucinatory states in response to stress. The development of MAP psychosis might therefore be related to persisting brain damage or changes in brain metabolism induced by repeated MAP use, and thus studies of the clinical course and neurological basis of MAP psychosis could provide insights into the pathophysiology of schizophrenia. Accordingly, psychiatrists have studied the clinical characteristics of MAP psychosis and examined the neurobiological basis of MAP-induced behavioral sensitization, using animals. MAP-induced behavioral sensitization might well be related to dopamine supersensitivity; however, the contribution of presynaptic autoreceptors remains controversial, and other hypotheses should be considered. Recently, the process that triggers spontaneous recurrence of MAP psychosis (flashbacks) and corresponding peripheral neurotransmitter functions has been studied. Stress sensitization associated with noradrenergic hyperactivity, involving increased dopamine release, appears to be crucial in the development of flashbacks. Overall, MAP-induced susceptibility to paranoid-hallucinatory states and to abnormal behavior (e.g., stereotyped behavior) in animals is examined as a model for predicting relapses of paranoid schizophrenia. Further extensive studies on the neurobiological and molecular mechanisms of this susceptibility are required.

Susceptibility to subsequent episodes in spontaneous recurrence of methamphetamine psychosis

The relation is examined between increased sensitivity to stress associated with noradrenergic hyperactivity and dopaminergic changes, and susceptibility to subsequent spontaneous recurrences of methamphetamine (MAP) psychosis (i.e., flashbacks). Plasma monoamine metabolite levels were assayed in 23 flashbackers, 19 nonflashbackers with a history of MAP psychosis, 10 subjects with persistent MAP psychosis, and 21 MAP user and 9 nonuser controls. All 23 flashbackers had undergone frightening stressful experiences during previous MAP use. Mild psychosocial stressors then triggered flashbacks. The 12 flashbackers with further episodes had markedly increased norepinephrine levels and slightly increased plasma levels of 3-methoxytyramine, an index of dopamine release. While the 11 flashbackers with a single episode displayed small increases in norepinephrine and 3-methoxytyramine levels. Thus, robust noradrenergic hyperreactivity, involving increased dopamine release in response to mild stress may predispose to further episodes of flashbacks.

Increased sensitivity to stress associated with noradrenergic hyperactivity, involving dopaminergic hyperactivity in spontaneous recurrences in methamphetamine psychosis

Abstract The study examined the significance of increased sensitivity to stress associated with noradrenergic hyperactivity and dopaminergic changes in spontaneous recurrences of methamphetamine (MAP) psychosis (flashbacks). Plasma monoamine metabolite levels were assayed in the subjects: 19 flashbackers, 18 non-flashbackers with a history of MAP psychosis and 37 controls. Monoaminergic values underwent a square-root transformation. All flashbackers had been exposed to stressful events plus MAP-induced fear-related psychotic symptoms (n = 11) or fear-related symptoms alone (n = 8). Factors triggering flashbacks met the DSM-III-R criteria for mild psychosocial stressors. During flashbacks norepinephrine levels increased markedly and 3-methoxytyramine, which is indicative of dopaminergic activity, increased to a lesser extent. Among the flashbackers, 11 with a history of stressful events plus fear-related symptoms displayed further a small increase in 3-methoxytyramine levels. Thus, stressful events plus fear-related symptoms, together with MAP use, may induce noradrenergic hyperactivity and some degree of dopaminergic hyperactivity in response to mild stressors. Increased sensitivity to stress associated with a predominance of noradrenergic over dopaminergic hyperactivity may be a precipitating factor in flashbacks.

Increased sensitivity to stress in spontaneous recurrence of methamphetamine psychosis: noradrenergic hyperactivity with contribution from dopaminergic hyperactivity

The significance of increased sensitivity to stress associated with noradrenergic hyperactivity involving dopaminergic change in spontaneous recurrences of methamphetamine (MAP) psychosis (flashbacks) was examined. Plasma monoamine metabolite levels were assayed in 18 subjects with flashbacks who had been exposed to stressful events plus MAP-induced frightening psychotic symptoms (N = 11) or frightening psychotic symptoms alone (N = 7) during previous MAP use, in 15 nonflashbackers with a history of MAP psychosis, in 8 subjects with persistent MAP psychosis, and in 27 control subjects. Monoaminergic values were subjected to a square-root transformation, rendering the distribution normal. The numbers of stressful events (mostly threatening events) and frightening psychotic symptoms were significantly higher in the flashbackers than in the nonflashbackers. Factors triggering flashbacks were mild psychosocial stressors (mostly a mild fear of other people). During flashbacks, plasma norepinephrine levels increased, and the flashbackers, 11 of whom had experienced stressful events plus frightening psychotic symptoms, had an additional small increase in plasma levels of 3-methoxytyramine, which is indicative of dopamine release. Thus, threatening stressful events, together with MAP use, may induce noradrenergic hyperreactivity to subsequent mild stressors. Threatening, stressful events plus frightening psychotic symptoms may further induce increased dopamine release in response to mild stressors. Increased sensitivity to stress associated with noradrenergic hyperactivity involving increased dopamine release may have elicited memories of MAP psychosis related to frightening, stressful experiences. The increased sensitivity may be critical for the development of flashbacks.

Stress induced spontaneous recurrence of methamphetamine psychosis: the relation between stressful experiences and sensitivity to stress

We examined increased sensitivity to stress in relation to spontaneous recurrences of methamphetamine (MAP) psychosis (i.e., flashbacks). Plasma monoamine metabolite levels were assayed in: 26 flashbackers, of whom 11 were on neuroleptics before and during the study, and the other 15 received neuroleptics in the course of the study; 18 non-flashbackers with a history of MAP psychosis; eight subjects with persistent MAP psychosis; and 23 MAP user and 11 non-user controls. The 26 flashbackers had experienced stressful events and/or MAP-induced fear-related psychotic symptoms during previous MAP use. Mild psychosocial stressors then triggered flashbacks. During flashbacks plasma norepinephrine levels increased markedly; among the flashbackers, those with a history of stressful events, whether or not they had experienced fear-related symptoms, showed a further increase in 3-methoxytyramine levels. Stressful experiences, together with MAP use, may therefore induce sensitization to stress associated with noradrenergic hyperactivity, involving increased dopamine release, and so triggering flashbacks.

Neurobiological basis of relapse prediction in stimulant-induced psychosis and schizophrenia: the role of sensitization

A number of consistent clinical observations provide direction for the hypothesis that pathological sensitization of neuronal systems may be an important factor for relapse or the onset of stimulant-induced psychosis (eg, methamphetamine or amphetamine psychosis, cocaine psychosis and phencyclidine psychosis) and schizophrenia. First, psychotic symptoms can be produced in normal subjects by stimulants. Secondly, a large portion of schizophrenic patients exhibit exacerbation of psychotic symptoms in response to stimulants at doses which would not be psychotogenic in normal subjects. Lastly, the ability of stress to precipitate the onset and relapse of schizophrenia is well documented. In this regard, acute responses to stimulants provide useful information for relapse prediction of schizophrenia and substance abuse. This paper addresses the nature and role of pathological sensitization in relapse of stimulant- and phencyclidine-induced psychosis and schizophrenia, and its relation to pathophysiology of schizophrenia.

Increased sensitivity to stress and episode recurrence in spontaneous recurrence of methamphetamine psychosis

Increased sensitivity to stress associated with noradrenergic hyperactivity and dopaminergic changes may precipitate stress-related psychiatric disorders. The present study examines the relation between this increased sensitivity and vulnerability to subsequent spontaneous recurrences of methamphetamine (MAP) psychosis (i.e. flashbacks). Plasma monoamine metabolite levels were assayed in 18 subjects with flashbacks, of whom ten experienced a single flashback and eight experienced further subsequent flashbacks; in 21 subjects with a history of MAP psychosis who did not experience flashbacks; and 33 controls. A square-root transformation was applied to monoaminergic values, rendering the distribution normal. The subjects with flashbacks had undergone frightening stressful experiences during previous MAP use. The dominant factor triggering flashbacks was a mild fear of other people. During flashbacks, plasma noradrenaline levels markedly increased and 3-methoxytyramine levels, an indicator of dopamine release, were elevated. Among the 18 subjects with flashbacks, the ten with subsequent flashbacks had markedly increased noradrenaline levels during flashbacks, whereas the eight with a single flashback displayed small increases in noradrenaline levels as well as 3-methoxytyramine levels. Thus, a mild fear of other people may have elicited memories of MAP psychosis, related to frightening stressful experiences through increased sensitivity to stress associated with noradrenergic hyperactivity, involving increased dopamine release. Robust noradrenergic hyperreactivity to mild stress may predispose subjects to subsequent flashbacks.

[Clinical efficacy of olanzapine]

The treatment of schizophrenic patients who fail adequate trials of typical neuroleptics is a major challenge. For these patients, the availability of atypical antipsychotics is a useful therapeutic advance. Olanzapine shows a superior and broader spectrum of efficacy in the treatment of schizophrenia, particularly its negative symptoms, with a substantially more favorable safety profile than conventional antipsychotic agents (e.g., haloperidol). However, little information on the clinical effects of olanzapine is available in Japan. This article provides information on the efficacy of olanzapine for various symptoms of schizophrenic patients and drug safety. Olanzapine is significantly superior to haloperidol in positive, negative, and depressive symptoms of patients, and for tardive dyskinesia and extrapyramidal symptoms. Significantly greater improvement in avolition-apathy is achieved with olanzapine as compared to risperidone. These advantages are related to high affinity at the 5-HT2 binding site, no association with an alteration in dopamine A9 firing rates, and lower D2 striatal receptor blockade of olanzapine. Treatment with 10 mg/day olanzapine is more appropriate for positive symptoms, and 12.5-17.5 mg/day olanzapine is more effective for negative symptoms. Patients will need help adapting to a new level of functioning after a successful switch to olanzapine, and overcoming the disappointment that eventually occurs when the limitations of olanzapine become apparent.

Spontaneous recurrence of methampetamine psychosis: increased sensitivity to stress associated with noradrenergic hyperactivity and dopaminergic change

We studied the factors precipitating spontaneous recurrences of methamphetamine (MAP)-induced paranoid-hallucinatory states (referred to as "flashbacks") in 28 flashbackers, along with 18 non-flashbackers with a history of MAP psychosis. Plasma levels of catecholamines and their metabolites were assayed in the 28 flashbackers, the 18 non-flashbackers, 8 subjects with persistent MAP psychosis, and 33 normal controls (22 MAP users and 11 non-users). The flashbackers had been exposed to significantly higher numbers of stressful events, and/or MAP-induced frightening paranoid-hallucinatory states during previous MAP use, than the non-flashbackers. Factors triggering the flashbacks met the DSM-III-R criteria for a mild psychosocial stressor. During flashbacks, plasma norepinephrine levels increased and plasma levels of 3-methoxytyramine, which is an indicator of dopamine release, showed a smaller increase. It follows that stressful experiences together with MAP use may induce sensitization to mild psychosocial stressors. Noradrenergic hyperactivity and some degree of increased dopamine release may be involved in this process. Stress sensitization may elicit memories of MAP psychosis associated with stressful experiences in response to mild psychosocial stressors, leading to the occurrence of flashbacks. Sensitization to stress associated with noradrenergic hyperactivity, involving increased dopamine release may be central to spontaneous recurrences of MAP psychosis.

Cytotoxic T-lymphocyte-mediated lysis of Toxoplasma gondii-infected target cells does not lead to death of intracellular parasites

CD8(+) T cells play a crucial role in the control of infection with intracellular microbes. The mechanisms underlying the CD8(+) T-cell-mediated clearance of the intracellular pathogen Toxoplasma gondii are, however, not completely understood. The effect of CD8(+) cytotoxic T-lymphocyte (CTL)-mediated lysis of host cells on the viability of intracellular T. gondii was investigated. Quantitative competitive PCR of the gene encoding T. gondii major surface antigen (SAG-1) was combined with treatment of the parasites with DNase, which removed the DNA template of nonviable parasites. The induction by CD8(+) CTLs of apoptosis in cells infected with T. gondii did not result in the reduction of live parasites, indicating that intracellular T. gondii remains alive after lysis of host cells by CTLs.

Measurement of postprandial remnant-like particles (RLPs) following a fat-loading test

To assess the usefulness of remnant-like particles (RLPs), which represent potentially atherogenic lipoprotein remnants, as an index of postprandial hyperlipidemia, RLPs and other lipids were measured in 19 healthy adults (23-44 years old) after ingestion of a test meal (fat content, 32.9%). The lipoprotein derivatives, with a marked increase after fat-loading, were triglycerides, retinyl palmitate and RLPs. The retinyl palmitate peak lagged behind the RLP and triglyceride peaks, indicating that it may have different kinetics than RLP and triglyceride. While triglycerides are considered as an index of atherosclerotic risk factor, RLPs also may be a suitable index for evaluating postprandial hyperlipidemia. RLPs remained high even 8 h after fat-loading, suggesting that the postprandial state persists for almost the whole day. Accordingly, it may be important to assess postprandial remnant concentrations.

Unique molecular surface features of in vivo tolerized T cells

Differential expression of surface markers can frequently be used to distinguish functional subsets of T cells, yet a surface phenotype unique to T cells induced into an anergic state has not been described. Here, we report that CD4 T cells rendered anergic in vivo by superantigen can be identified by loss of the 6C10 T cell marker. Inoculation of Vbeta8.1 T cell antigen receptor (TCR) transgenic mice with a Vbeta8.1-reactive minor lymphocyte-stimulating superantigen (Mls-1(a)) induces tolerance to Mls-1(a) by clonal anergy. CD4 lymph node T cells from Mls-1(a) inoculated transgenic mice enriched for the 6C10(-) phenotype neither proliferate nor produce interleukin-2 upon TCR engagement, whereas 6C10(+) CD4 T cells retain responsiveness. Analysis of T cell memory markers demonstrate that 6C10(-) T cells remain 3G11(hi) but express heterogeneous levels of CD45RB, CD62L, CD44, and the CD69 early activation marker, suggesting that T cells at various degrees of activation can be functionally anergic. These studies demonstrate that anergic T cells can be purified based on 6C10 expression permitting examination of issues concerning biochemical and biological features specific to T cell anergy.

Factors affecting the development of spontaneous recurrence of methamphetamine psychosis

The process triggering spontaneous recurrences of methamphetamine (MAP) psychosis (i.e. flashbacks) was studied in 41 flashbackers, along with 84 non-flashbackers with a history of MAP psychosis. Plasma monoamine metabolite levels were assayed in 25 of the 41 flashbackers, 16 of the 84 non-flashbackers, 9 subjects with persistent MAP psychosis and 28 control subjects. All flashbackers had experienced threatening events or frightening paranoid-hallucinatory states during previous MAP use. The dominant factor triggering flashbacks was a mild fear of other people. Plasma norepinephrine levels were elevated during flashbacks. The results suggest that a mild fear of other people may have elicited memories of MAP psychosis associated with threatening experiences through increased sensitivity to psychosocial stressors. As a result the flashbacks occurred, including an increase in peripheral noradrenergic activity.

Precipitating factors in spontaneous recurrence of methamphetamine psychosis

This paper examines noradrenergic hyperactivity in response to stress in the development of spontaneous recurrences of methamphetamine (MAP) psychosis, a phenomenon known as flashbacks, in studies of psychedelic drug use. We studied predictors of flashbacks in 36 subjects with flashbacks, along with 80 subjects with a history of MAP psychosis who did not experience flashbacks. Plasma monoamine metabolite levels were assayed in 26 of the 36 subjects with flashbacks, 16 of the 80 subjects without flashbacks, nine subjects with persistent MAP psychosis, and 28 normal controls. None of the 28 controls became psychotic. A square root transformation was applied to all monoaminergic values, resulting in data nearly normally distributed. The subjects with flashbacks had been exposed to stressful events or threatening paranoid-hallucinatory states or both during previous MAP use. Most flashbacks occurred under conditions that provoked a mild fear of other people. Plasma norepinephrine levels were markedly increased during flashbacks. Thus, stressful experiences together with MAP use may have induced noradrenergic hyperreactivity to a mild stress, which in turn may elicit memories of MAP psychosis associated with stressful experiences. A mild fear of other people precipitated the flashbacks, including markedly increased noradrenergic activity. The results of this study suggest that noradrenergic hyperreactivity to a mild stress is a precipitating factor in spontaneous recurrences of MAP psychosis.

Oxidation of remnant-like particles from serum of diabetic patients, patients with ischemic heart disease and normal subjects

Remnant-like particles (RLP) are reportedly involved in the pathogenesis of atherosclerosis, as are lipid peroxides. To assess the role of the oxidation of RLP in this disease, we compared the oxidation of RLP with that of total very low density lipoproteins (VLDL) obtained from the serum of 10 patients with ischemic heart disease (IHD), 10 patients with diabetes mellitus (DM) and 10 normal subjects by measuring the levels of thiobarbituric acid reactive substances (TBARS). Our results indicated that RLP were oxidized in vivo to a greater extent than total VLDL in all three groups of subjects. The serum levels of RLP were significantly higher in the patients than in the normal subjects. The oxidation of RLP may therefore be involved in the progression of atherosclerosis in patients with IHD or DM.

New assay for glycated lipoproteins by high-performance liquid chromatography

We developed an automated analytic system for glycated lipoprotein using high-performance liquid chromatography (HPLC) with an affinity boronate column and a gel permeation column. This system can measure glycated lipoprotein (glycated LDL and glycated HDL) in a small (5 microliters) sample of serum in a short time (40 min/sample). Recovery with this system was 92.1%. Therefore a large number of samples can be measured in clinical use. The system should contribute to an elucidation of the role of glycated lipoprotein in atherosclerosis.

Noradrenergic activity and spontaneous recurrence of methamphetamine psychosis

The process that triggers flashbacks due to previous methamphetamine (MAP) psychosis was studied in 28 flashbackers, along with 84 non-flashbackers with a history of MAP psychosis. We measured plasma monoamine metabolite levels in 12 of the flashbackers and eight of the non-flashbackers, along with 28 normal controls. Most flashbackers had undergone frightening experiences during previous MAP use. The dominant triggering factor was a mild fear of other people. Plasma norepinephrine (NE) levels in the 12 flashbackers were increased during flashbacks. Thus, MAP use associated with threatening experiences may have increased sensitivity to stressors, leading to the occurrence of flashbacks, including exaggerated noradrenergic activity.

Methamphetamine psychosis: spontaneous recurrence of paranoid-hallucinatory states and monoamine neurotransmitter function

We studied the process that triggers spontaneous recurrences of methamphetamine (MAP) psychosis, a phenomenon known as flashbacks, in 28 female patients who experienced flashbacks, by comparing them with 92 female nonflashbackers with a history of previous MAP psychosis. The study evaluated plasma monoamine neurotransmitter function in 12 of the 28 flashbackers and in 8 of the 92 nonflashbackers. Control data were obtained from 28 normal, healthy females composed of 13 MAP users and 15 nonusers, none of whom became psychotic. The 28 flashbackers had experienced significantly greater frequencies of threatening events and frightening paranoid-hallucinatory states during previous MAP abuse than the 92 nonflashbackers. The dominant triggering factor was a mild fear of other persons. Plasma norepinephrine (NE) levels were significantly higher in the 12 flashbackers during flashbacks than during periods of normalcy and were significantly higher than those in the 13 user and 15 nonuser control subjects. Plasma NE levels in the 12 flashbackers during periods of normalcy were significantly higher than those in the 13 user control subjects. The eight nonflashbackers had significantly higher NE levels than the 13 user control subjects. This suggests that an increase in peripheral noradrenergic activity may be related to the occurrence of flashbacks. The present study suggests that repeated MAP use with frightening experiences may induce sensitivity to psychosocial stressors. A mild fear of other persons may have actualized the encoded frightening memories associated with the frightening experiences via increased sensitivity to psychosocial stressors. Thus, flashbacks may have been caused through an increase in peripheral noradrenergic activity.

Monoamine neurotransmitter metabolites and spontaneous recurrence of methamphetamine psychosis

The present study was conducted to evaluate plasma levels of monoamine neurotransmitter metabolites in spontaneous recurrences of methamphetamine psychosis (i.e., flashbacks). The subjects were 50 physically healthy females comprised of 25 who experienced flashbacks (flashbackers), 18 who did not experienced methamphetamine psychosis, and 9 who were currently suffering from persistent methamphetamine psychosis. The control data were available from 28 normal healthy females, of whom 20 had previously abused methamphetamine (users) and 8 who had not (nonusers), none of whom had ever become psychotic. Plasma levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT), and their respective metabolites were assayed. Plasma NE levels were significantly higher in the 25 flashbackers during their flashbacks than during their periods of normalcy, and were significantly higher than those in the 20 user and 8 nonuser controls. Plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels during flashbacks were significantly higher than those in the 20 user controls. The nine subjects with persistent methamphetamine psychosis had significantly higher NE levels than the user and nonuser controls. The 16 nonflashbackers had significantly higher MHPG levels than the user controls. The present study suggests that an increase in peripheral noradrenergic activity is related to the occurrence of flashbacks.