Susceptibility to subsequent episodes in spontaneous recurrence of methamphetamine psychosis

Spurious Autobiographical Memory of Psychosis: A Mechanistic Hypothesis for the Resolution, Persistence, and Recurrence of Positive Symptoms in Psychotic Disorders

Psychotic disorders are complex disorders with multiple etiologies. While increased dopamine synthesis capacity has been proposed to underlie psychotic episodes, dopamine-independent processes are also involved (less responsive to dopamine receptor-blocking medications). The underlying mechanism(s) of the reduction in antipsychotic responsiveness over time, especially after repeated relapses, remain unclear. Despite the consistent evidence of dopamine overactivity and hippocampal volume loss in schizophrenia, few accounts have been provided based on the interactive effect of dopamine on hippocampal synapse plasticity mediating autobiographical memory processes. The present hypothesis builds upon previous works showing the potential effects of dopamine overactivity on hippocampal-mediated neuroplasticity underlying autobiographical memory, alongside known patterns of autobiographical memory dysfunction in psychosis. We propose that spurious autobiographical memory of psychosis (SAMP) produced during active psychosis may be a key mechanism mediating relapses and treatment non-responsiveness. In a hyperdopaminergic state, SAMP is expected to be generated at an increased rate during active psychosis. Similar to other memories, it will undergo assimilation, accommodation, and extinction processes. However, if SAMP fails to integrate with existing memory, a discontinuity in autobiographical memory may result. Inadequate exposure to normalizing experiences and hyposalience due to overmedication or negative symptoms may also impede the resolution of SAMP. Residual SAMP is hypothesized to increase the propensity for relapse and treatment non-responsiveness. Based on recent findings on the role of dopamine in facilitating hippocampal synapse plasticity and autobiographical memory formation, the SAMP hypothesis is consistent with clinical observations of DUP effects, including the repetition of contents in psychotic relapses as well as the emergence of treatment non-responsiveness after repeated relapses. Clinical implications of the hypothesis highlight the importance of minimizing active psychosis, integrating psychosis memory, avoiding over-medication, and fostering normalizing experiences.

A latent class analysis of psychiatric symptom profiles associated with past-month methamphetamine use

We explored latent psychiatric symptom profiles associated with methamphetamine use, and examined how these corresponded to diagnoses of schizophrenia (SZ) and methamphetamine-associated psychosis (MAP). We assessed psychiatric symptoms among 160 people who had used methamphetamine in the past month. Psychiatric symptoms were defined as a score of 4+ on Brief Psychiatric Rating Scale (BPRS) items. Diagnoses were made using the Composite International Diagnostic Interview (CIDI). Participants were defined as having MAP if they met symptom criteria for SZ, but symptoms were considered to be always the result of substance use. Latent class analysis identified three classes. Class one (44% of participants) had a low probability of most BPRS symptoms; 4% met criteria for SZ, 51% for MAP. Class two (31% of participants) had a higher probability hallucinations and suspiciousness (37-46%); 72% met criteria for MAP, and 7% for SZ. Class three (25% of participants) had the highest probability for all positive psychotic symptoms (hallucinations, suspiciousness, grandiosity, unusual thought content; 32-82%), and reported activation, conceptual disorganisation, and tension (35% met criteria for SZ and 17% for MAP). We found three distinct classes of psychiatric symptom profiles, two of which showed partial alignment with diagnostic constructs of SZ and MAP.

Organic vs Stimulant-Induced Psychosis in the Peripartum Period

This is the case of a 30-year-old pregnant female who presented to the medical emergency department with signs and symptoms consistent with a psychotic episode. At the time of presentation, the patient was noted to have paranoia and delusions focused on her current pregnancy. On further evaluation in the emergency department, the patient’s urine toxicology was found to be positive for methamphetamines. Following medical clearance, the patient was admitted for acute inpatient psychiatric stabilization. During hospitalization, her psychosis rapidly resolved with only the use of two emergency treatment injections containing antipsychotic medication. This case presents an interesting differential diagnosis between a brief psychotic disorder with peripartum onset and a substance-induced psychosis, and allows for further discussion in the differentiation and clinical treatment of these diagnoses. 

Methamphetamine-induced sensitization is associated with alterations to the proteome of the prefrontal cortex: implications for the maintenance of psychotic disorders

Repeat administration of psychostimulants, such as methamphetamine, produces a progressive increase in locomotor activity (behavioral sensitization) in rodents that is believed to represent the underlying neurochemical changes driving psychoses. Alterations to the prefrontal cortex (PFC) are suggested to mediate the etiology and maintenance of these behavioral changes. As such, the aim of the current study was to investigate changes to protein expression in the PFC in male rats sensitized to methamphetamine using quantitative label-free shotgun proteomics. A methamphetamine challenge resulted in a significant sensitized locomotor response in methamphetamine pretreated animals compared to saline controls. Proteomic analysis revealed 96 proteins that were differentially expressed in the PFC of methamphetamine treated rats, with 20% of these being previously implicated in the neurobiology of schizophrenia in the PFC. We identified multiple biological functions in the PFC that appear to be commonly altered across methamphetamine-induced sensitization and schizophrenia, and these include synaptic regulation, protein phosphatase signaling, mitochondrial function, and alterations to the inhibitory GABAergic network. These changes could inform how alterations to the PFC could underlie the cognitive and behavioral dysfunction commonly seen across psychoses and places such biological changes as potential mediators in the maintenance of psychosis vulnerability.

Computer-aided (in silico) approaches in the mode-of-action analysis and safety assessment of ostarine and 4-methylamphetamine

OBJECTIVE

This study exemplifies computer-aided (in silico) approaches in assessing the risks of new psychoactive substances emerging in the European Union. In this work, we (i) consider the potential of Ostarine exhibiting psychoactivity and (ii) anticipate potential activities and toxicities of 4-methylamphetamine.

METHOD

The approach, termed in silico target prediction, suggests potential protein targets modulated by compounds given their chemical structure. This is achieved by first establishing the associations between chemical structure and protein targets using data from the bioactivity database, ChEMBL, via the use of two different computational algorithms. On the basis of the associations, protein targets and consequently the mode of action of novel compounds were predicted.

RESULTS

For Ostarine, none of the targets anticipated are currently known to elicit psychoactivity. Furthermore, Ostarine is unlikely to cross the blood-brain barrier to reach relevant target sites on the basis of its physicochemical properties. For 4-methylamphetamine, toxicities were anticipated, that is, serotonin syndrome (based on the prediction of SERT) and other effects similar to related substances, that is, methamphetamine.

CONCLUSION

From the two case studies, we showed that in silico target prediction appears to have potential in assessing new psychoactive compounds where experimental data are scarce. The applicability domain of target predictions when applied to psychoactive compounds needs to be established in future work.

Amphetamine-induced psychosis--a separate diagnostic entity or primary psychosis triggered in the vulnerable?

Use of amphetamine and methamphetamine is widespread in the general population and common among patients with psychiatric disorders. Amphetamines may induce symptoms of psychosis very similar to those of acute schizophrenia spectrum psychosis. This has been an argument for using amphetamine-induced psychosis as a model for primary psychotic disorders. To distinguish the two types of psychosis on the basis of acute symptoms is difficult. However, acute psychosis induced by amphetamines seems to have a faster recovery and appears to resolve more completely compared to schizophrenic psychosis. The increased vulnerability for acute amphetamine induced psychosis seen among those with schizophrenia, schizotypal personality and, to a certain degree other psychiatric disorders, is also shared by non-psychiatric individuals who previously have experienced amphetamine-induced psychosis. Schizophrenia spectrum disorder and amphetamine-induced psychosis are further linked together by the finding of several susceptibility genes common to both conditions. These genes probably lower the threshold for becoming psychotic and increase the risk for a poorer clinical course of the disease.The complex relationship between amphetamine use and psychosis has received much attention but is still not adequately explored. Our paper reviews the literature in this field and proposes a stress-vulnerability model for understanding the relationship between amphetamine use and psychosis.

Gender Differences in Psychiatric Symptoms among Methamphetamine Dependent Residents in Sober Living Houses

OBJECTIVES

Although psychiatric symptoms among methamphetamine (MA) dependent individuals have been studied in treatment programs, they have not been examined in services designed to support sustained recovery in the community (e.g. sober living houses). In addition, some disorders more common among women, such as somatoform and bulimia, have been understudied among MA dependent individuals. This study aimed to examine psychiatric symptom differences between MA dependent men and women who we entering sober living houses (SLHs).

METHODS

Two hundred forty five individuals were interviewed within one week of entering SLHs. Instruments included a DSM IV based measure for MA dependence, a psychiatric screen (the Psychiatric Diagnostic Screening Questionnaire), demographics, recent substance use and recent use of services.

RESULTS

Of the 245 participants, 103 men and 25 women met criteria for MA dependence. Womenwith MA dependence reported more psychiatric symptoms than men. They also trended toward reporting more psychiatric symptoms than non-MA dependent women. For men, psychiatric symptoms did not vary between those with and without MA dependence. Some understudied disorders (e.g., somatoform) had large proportions of women meeting the screening criteria.

CONCLUSIONS

Additional research is needed on understudied psychiatric disorders that are common among MA dependent women. SLH's should consider ways to address psychiatric symptoms among MA dependent individuals, especially women. Strategies could include increasing linkages with professional mental health services as well as developing peer oriented strategies for managing symptoms.

Treatment for amphetamine psychosis

BACKGROUND

Chronic amphetamine users may have experience of paranoia and hallucination. It has long been believed that dopamine antagonists, such as chlorpromazine, haloperidol, and thioridazine, are effective for the treatment of amphetamine psychosis.

OBJECTIVES

To evaluate risks, benefits, costs of treatments for amphetamine psychosis.

SEARCH STRATEGY

MEDLINE (1966-2007), EMBASE (1980-2007), CINAHL (1982-2007), PsychINFO (1806-2007), CENTRAL (Cochrane Library 2008 issue 1), references of obtained articles.

SELECTION CRITERIA

All randomised controlled and clinical trials (RCTs, CCTs) evaluating treatments (alone or combined) for people with amphetamine psychosis

DATA COLLECTION AND ANALYSIS

Two authors evaluated and extracted the data independently. Dichotomous data were extracted on an intention-to-treat basis in which the dropouts were assigned as participants with the worst outcomes. The Relative Risk (RR) with the 95% confidence interval (95% CI) was used to assess the dichotomous data. The Weighted Mean Difference (WMD) with 95% CI was used to assess the continuous data.

MAIN RESULTS

The comprehensive searches found one randomised controlled trial of treatment for amphetamine psychosis meeting the criteria for considering studies. The study involved 58 participants and compared the efficacy and tolerability of two antipsychotic drugs, olanzapine (a newer antipsychotic) and haloperidol (a commonly used antipsychotic medication used as a control condition), in treating amphetamine-induced psychosis. The results show that both olanzapine and haloperidol at clinically relevant doses were efficacious in resolving psychotic symptoms, with the olanzapine condition showing significantly greater safety and tolerability than the haloperidol control as measured by frequency and severity of extrapyramidal symptoms.

AUTHORS' CONCLUSIONS

Only one RCT of treatment for amphetamine psychosis has been published. Outcomes from this trial indicate that antipsychotic medications effectively reduce symptoms of amphetamine psychosis, the newer generation and more expensive antipsychotic medication, olanzapine, demonstrates significantly better tolerability than the more affordable and commonly used medication, haloperidol.There are other two studies that did not meet the inclusion criteria for this review. The results of these two studies show that agitation and some psychotic symptoms may be abated within an hour after antipsychotic injection.Whether this limited evidence can be applied for amphetamine psychotic patients is not yet known.The medications that should be further investigate are conventional antipsychotics, newer antipsychotics and benzodiazepines. However, naturalistic studies of amphetamine psychotic symptoms and the prevalence of relapse to psychosis in the presence of amphetamine, are also crucial for advising the development of study designs appropriate for further treatment studies of amphetamine psychosis.

Treatment for amphetamine psychosis

BACKGROUND

Chronic amphetamine users may have experience of paranoia and hallucination. It has long been believed that dopamine antagonists, such as chlorpromazine, haloperidol, and thioridazine, are effective for the treatment of amphetamine psychosis.

OBJECTIVES

To evaluate risks, benefits, costs of treatments for amphetamine psychosis.

SEARCH STRATEGY

MEDLINE (1966-2007), EMBASE (1980-2007), CINAHL (1982-2007), PsychINFO (1806-2007), CENTRAL (Cochrane Library 2008 issue 1), references of obtained articles.

SELECTION CRITERIA

All randomised controlled and clinical trials (RCTs, CCTs) evaluating treatments (alone or combined) for people with amphetamine psychosis

DATA COLLECTION AND ANALYSIS

Two authors evaluated and extracted the data independently. Dichotomous data were extracted on an intention-to-treat basis in which the dropouts were assigned as participants with the worst outcomes. The Relative Risk (RR) with the 95% confidence interval (95% CI) was used to assess the dichotomous data. The Weighted Mean Difference (WMD) with 95% CI was used to assess the continuous data.

MAIN RESULTS

The comprehensive searches found one randomised controlled trial of treatment for amphetamine psychosis meeting the criteria for considering studies. The study involved 58 participants and compared the efficacy and tolerability of two antipsychotic drugs, olanzapine (a newer antipsychotic) and haloperidol (a commonly used antipsychotic medication used as a control condition), in treating amphetamine-induced psychosis. The results show that both olanzapine and haloperidol at clinically relevant doses were efficacious in resolving psychotic symptoms, with the olanzapine condition showing significantly greater safety and tolerability than the haloperidol control as measured by frequency and severity of extrapyramidal symptoms.

AUTHORS' CONCLUSIONS

Only one RCT of treatment for amphetamine psychosis has been published. Outcomes from this trial indicate that antipsychotic medications effectively reduce symptoms of amphetamine psychosis, the newer generation and more expensive antipsychotic medication, olanzapine, demonstrates significantly better tolerability than the more affordable and commonly used medication, haloperidol.There are other two studies that did not meet the inclusion criteria for this review. The results of these two studies show that agitation and some psychotic symptoms may be abated within an hour after antipsychotic injection. Whether this limited evidence can be applied for amphetamine psychotic patients is not yet known.The medications that should be further investigate are conventional antipsychotics, newer antipsychotics and benzodiazepines. However, naturalistic studies of amphetamine psychotic symptoms and the prevalence of relapse to psychosis in the presence of amphetamine, are also crucial for advising the development of study designs appropriate for further treatment studies of amphetamine psychosis.

Methamphetamine-related emergency department utilization and cost

OBJECTIVE

To quantify the frequency, cost, and characteristics associated with emergency department (ED) visits that are related to methamphetamine use.

METHODS

This was a prospective observational study. The authors performed a training program for ED clinicians on the acute and chronic effects of methamphetamine and the signs of methamphetamine abuse. A standardized two question survey was administered to clinicians concerning the relationship between the ED visit and the patient's methamphetamine use. The survey was embedded in the patient tracking system and was required for all ED patients before disposition. Survey results were merged with administrative data on demographics, diagnosis, disposition, and charges. Univariate analyses were used to determine patient characteristics associated with methamphetamine-related ED visits.

RESULTS

The authors examined 15,038 ED visits over a 20-week period from February 2006 to June 2006. There were a total of 353 methamphetamine-related visits, for an average of 17.65 visits per week (2.4% of all visits). Hospital charges for methamphetamine-related ED visits averaged $133,181 per week, for an estimated total of $6.9 M in annual charges. Methamphetamine-related ED patients were more likely to be male (odds ratio [OR] 1.6, 95% confidence interval [CI] = 1.30 to 2.01), white (OR 1.8, 95% CI = 1.38 to 2.29), and uninsured (OR 3.2, 95% CI = 2.21 to 4.69). The top four medical conditions associated with methamphetamine-related visits were mental health (18.7%), trauma (18.4%), skin infections (11.1%), and dental diagnoses (9.6%).

CONCLUSIONS

Methamphetamine abuse accounts for a modest but substantial proportion of ED utilization and hospital cost. Methamphetamine-related ED visits are most commonly related to mental illness, trauma, skin, and dental-related problems.

Substance use and abuse in first-episode psychosis: prevalence before and after early intervention

Despite the high prevalence of substance abuse among first-episode psychosis (FEP) populations, few studies examine whether early intervention (EI) improves substance abuse.

OBJECTIVE

To examine the prevalence and pattern of substance use and abuse among an FEP sample over 12 months.

METHODS

All the participants were diagnosed with a first episode of a schizophrenia spectrum disorder. The participants were followed prospectively. The prevalence rates of substance use and abuse from this sample were compared before and after 12 months of EI services and were compared with rates observed in a sample from the general population.

RESULTS

A total of 200 participants (80.0% males; mean age 24 years) entered the study: 183 participants completed all the assessments at baseline, 131 participants completed all the assessments at 12 months. At baseline, the findings showed similar prevalence rates between the FEP sample and the general sample for lifetime cannabis use (60% vs 55%, respectively) and hazardous alcohol use (26% vs 21%) but significantly different prevalence rates for lifetime hallucinogen (29% vs 15%; P < .001) and cocaine use (20% vs 14%; P < .001). At 12 months, the prevalence rates for drug abuse (P < .01), hazardous alcohol use (P < .01), and concurrent drug abuse and hazardous alcohol use (P < .05) were significantly lower than at baseline.

CONCLUSION

Substance use and abuse decreased significantly after 12 months of EI services; EI services may be able to detect and to reduce substance use among FEP patients before it becomes a more serious disorder.