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

Epidemiological Characteristics and Risk Factors of Methamphetamine-Associated Psychotic Symptoms

Objective: To explore the epidemiological characteristics and the risk factors for methamphetamine (MA)-associated psychotic symptoms among MA users in China. Methods: A cross-sectional study was conducted between April, 2012 and October, 2015 among individuals for whom MA was the principal drug of use in a Compulsory Drug Detoxification Center in Beijing, Guangdong Province. Demographic, drug use and psychological characteristics were examined using a specifically-designed questionnaire, the Positive and Negative Syndrome Scale, Barratt Impulsive Scale, Hamilton Anxiety Scale and Beck Depression Inventory. Logistic regression was performed to explore the risk factors for MA-associated psychotic symptoms. Results: A total of 1685 participants were included. Participants were predominantly aged 30 or above, unemployed, and were unmarried Han Chinese men, with limited education. The duration of MA use was more than 3 months in 72.3%. 47.8% reported that the dose of MA use was ≥ 0.2 g per occasion of use. 11.5% had used two or more synthetic drugs. The prevalence of MA-associated psychotic symptoms was 17.0% among MA users during periods of abstinence. Multiple logistic regression analyses showed that a higher dose (≥0.2 g per time), a longer duration of MA use (>3 months) a history of heroin use and a history of tobacco use were associated with MA-associated psychotic symptoms, with adjusted odds ratios (ORs) of 1.96 (95% confidence interval [CI]: 1.40-2.76), 1.98 (95% CI: 1.33-2.96) and 2.45 (95% CI: 1.67-3.60), 1.78 (95% CI: 1.27-2.49) respectively. MA-associated psychotic symptoms were less common among married/cohabitating than unmarried (OR = 0.56; 95% CI: 0.39-0.81), and unemployed than employed (OR = 0.65; 95% CI: 0.47-0.92) individuals. MA users with anxiety and depression symptoms had significantly greater risk for MA-associated psychotic symptoms by 9.70 (6.92-13.59) and 1.90 (1.36-2.65) times respectively. Individuals with higher impulsivity were more likely to have MA-associated psychotic symptoms than those with lower (OR = 2.19; CI:1.50-3.20). Conclusion: MA-associated psychotic symptoms occurred frequently among MA users in China. The efforts that facilitate drug users' attempts to reduce MA use, abstain from poly-drug use, and control associated psychiatric symptoms and impulsivity should be supported because of their potential contribution to MA-associated psychotic symptoms in this population.

Methamphetamine-associated psychosis

Methamphetamine (METH) is a frequent drug of abuse in U.S. populations and commonly associated with psychosis. This may be a factor in frequent criminal justice referrals and lengthy treatment required by METH users. Persecutory delusions and auditory hallucinations are the most consistent symptoms of METH-associated psychosis (MAP). MAP has largely been studied in Asian populations and risk factors have varied across studies. Duration, frequency and amount of use as well as sexual abuse, family history, other substance use, and co-occurring personality and mood disorders are risk factors for MAP. MAP may be unique with its long duration of psychosis and recurrence without relapse to METH. Seven candidate genes have been identified that may be associated with MAP. Six of these genes are also associated with susceptibility, symptoms, or treatment of schizophrenia and most are linked to glutamatergic neurotransmission. Animal studies of pre-pulse inhibition, attenuation of social interaction, and stereotypy and alterations in locomotion are used to study MAP in rodents. Employing various models, rodent studies have identified neuroanatomical and neurochemical changes associated with METH use. Throughout this review, we identify key gaps in our understanding of MAP and suggest potential directions for future research.

An association study between catechol-O-methyl transferase gene polymorphism and methamphetamine psychotic disorder

OBJECTIVE

A series of methamphetamine psychosis reveals two kinds of clinical courses of methamphetamine psychosis: transient type and prolonged type. Furthermore, paranoid psychosis sometimes recurs without methamphetamine reuse, referred to as spontaneous relapse. Dysfunction of central dopaminergic neurotransmission has been implicated in the pathogenesis of these psychiatric states. Catechol-O-methyl transferase appears to play a unique role in regulating synaptic dopaminergic activity. This study aimed to investigate whether a functional polymorphism of the catechol-O-methyl transferase gene would be involved in the development of these psychiatric states.

BASIC METHODS

We examined the functional polymorphism of val 158 met (catechol-O-methyl transferase) in 143 patients with methamphetamine psychosis and 200 healthy controls in Japan. The patients were divided into subgroups by several characteristic clinical features.

MAIN RESULTS

We found a significant difference in the catechol-O-methyl transferase allele frequency between patients with spontaneous relapse and the controls (P=0.018, odds ratio=1.67). Odds ratio implied that the patients with spontaneous relapse had a nearly 1.7-fold higher rate of the low activity alleles (met) than the controls.

CONCLUSIONS

Our results indicate that the met allele frequency of the catechol-O-methyl transferase is associated with patients who experienced methamphetamine psychosis and spontaneous relapse, suggesting that patients with a met allele appear to be at increased risk of an adverse response to methamphetamine.

Involvement of serine/threonine protein phosphatases sensitive to okadaic acid in restraint stress-induced hyperlocomotion in cocaine-sensitized mice

We used okadaic acid (OA), a potent preferential inhibitor of PP2A and PP5 but not PP1 (PP subfamilies), to examine the involvement of serine/threonine protein phosphatase (PP) in behavioral sensitization stimulated by treatment with cocaine in mice. Repeated administration of cocaine (10 mg kg(-1)) once a day for five consecutive days produced a progressive increase in locomotor activity that was maintained after the cessation of cocaine treatment, as revealed by the fact that a challenge dose of cocaine given on day 7 of withdrawal reproduced an enhanced stimulant effect. On the seventh day of withdrawal, OA-sensitive PP activity and expression of PP2A and PP5, but not PP1gamma, were increased in whole-cell extract of the nucleus accumbens and the ventral tegmental area in cocaine-sensitized mice, compared to saline-treated mice. Restraint stress increased locomotor activity in cocaine-sensitized mice on day 7 after drug administration was ceased. The locomotor activity was more susceptible to restraint-elicited enhancement in cocaine-sensitized mice than in saline-treated mice. The restraint-induced hyperlocomotion was suppressed by a single intracerebroventricular injection of OA immediately before restraint in cocaine-sensitized mice, but this suppression did not occur in saline-treated mice. The membrane fraction of the whole brain in cocaine-sensitized mice showed that OA-sensitive activity levels rise after mice are subjected to restraint, and this is concomitant with an increase in expression levels of PP2A and PP5, but not PP1gamma. These results suggest that the upregulated OA-sensitive PPs are involved in stress-induced hyperlocomotion in cocaine-sensitized mice. There may be intracellular mechanisms mediating psychostimulant cross-sensitization to stress underlying the spontaneous recurrence of its psychosis.

Chronic stress augments the long-term and acute effects of methamphetamine

There is growing evidence that exposure to stress alters the acute effects of abused drugs on the CNS. However, it is not known whether stress augments the longer-term neurotoxic effects of psychostimulant drugs, such as methamphetamine. Methamphetamine at high doses decreases forebrain dopamine concentrations. The current study tested the hypothesis that 10 days of unpredictable stress augmented striatal dopamine depletions 7 days following four injections of either 7.5 or 10 mg/kg methamphetamine (1 injection every 2 h). Furthermore, to assess the effects of chronic stress on immediate responses to methamphetamine, extracellular striatal dopamine and methamphetamine concentrations, and rectal temperature were monitored during the methamphetamine injection regimen. Seven days following either a 7.5 mg/kg or 10 mg/kg methamphetamine injection regimen, male rats exposed to unpredictable stress showed greater depletions in striatal dopamine tissue content compared with non-stressed controls injected with methamphetamine. Stressed rats had increased hyperthermic responses and dopamine efflux in the striatum during the methamphetamine injections when compared with non-stressed control rats. Moreover, stressed rats had an increased mortality rate (33%) compared with non-stressed controls (16.7%) following four injections of 10 mg/kg methamphetamine. The enhanced acute and longer-term effects of methamphetamine in stressed rats was not due to a greater concentrations of methamphetamine in the striatum, as extracellular levels of methamphetamine during the injection regimen did not differ between the two groups. In summary, exposure to 10 days of chronic unpredictable stress augments longer-term depletions of dopamine in the striatum, as well as acute methamphetamine-induced hyperthermia and extracellular dopamine levels. These findings suggest that chronic stress increases the responsiveness of the brain to the acute pharmacological effects of methamphetamine and enhances the vulnerability of the brain to the neurotoxic effects of psychostimulants.

Rapid assessment of sexual behavior, drug use, human immunodeficiency virus, and sexually transmitted diseases in northern thai youth using audio-computer-assisted self-interviewing and noninvasive specimen collection

BACKGROUND

Drug use, unwanted pregnancy, human immunodeficiency virus (HIV) infection, and sexually transmitted diseases are serious health problems among Thai youth. The gravity of these problems demands high-quality data to direct public health policy and prevention programs. Previous studies of stigmatized behaviors have been hampered by participation bias and underreporting. To evaluate sexual behavior, disease, and drug use, we used audio-computer-assisted self-interviewing (ACASI) and noninvasive specimen collection methods. We also evaluated effectiveness of these methods in minimizing participation bias and underreporting.

METHODS

In late 1999, students aged 15 to 21 years attending 3 vocational schools were invited to participate in a cross-sectional survey. Consenting students completed a classroom-based ACASI interview using a confidential code number system. Oral fluid specimens were tested for HIV antibodies, and urine was tested for chlamydial and gonococcal nucleic acids, methamphetamines, and opiates.

RESULTS

Of 1736 invited students, 1725 (99%) agreed to participate. Of these, 48% of the male students and 43% of the female students reported ever having had sexual intercourse. Overall, the mean number of lifetime sexual partners was 4.6 among male participants (median: 2) and 2.8 among female participants (median: 1). Consistent use of condoms with steady partners was reported by 16% of male participants and 11% of female participants who had such partners. Of all male participants, 7% had ever paid for sex, 3% had ever sold sex, and 7% had ever been coerced to have sex. Of all female participants, 3% had ever sold sex and 21% had ever been coerced to have sex. Among women with a history of sexual intercourse, 27% reported at least 1 pregnancy. Of these pregnancies, 83% were terminated. Among those with sexual intercourse experience, the prevalence of HIV infection was 0.5%; of infection with Neisseria gonorrhoeae, 0.4%; and of infection with Chlamydia trachomatis, 5%. Twenty-nine percent of students reported ever having used methamphetamines. Ten percent had a methamphetamine-positive urine test. In the ACASI interview, 16% of these denied ever having used methamphetamines. The prevalence of opiate positive urine tests was low (0.2%).

CONCLUSION

This study shows that adolescents and young adults in Chiang Rai are at high risk for having unprotected intercourse, being coerced to have sex, unwanted pregnancy, sexually transmitted diseases, and drug use. The high enrollment rate demonstrates the feasibility and acceptability of using ACASI and noninvasive specimen collection methods in a developing country. ACASI use may lead to increased, but not to complete, self-reporting of sensitive behaviors.

The neurobiology of the stress cascade and its potential relevance for schizophrenia

This review explores the neurobiology of stress and its possible role in the etiology of schizophrenia. Major life events may play a role in onset and relapse in schizophrenia. Other data suggest that early stress exposure increases schizophrenia risk, especially in individuals with latent vulnerability. Animal research has led to an elucidation of the mechanisms by which stress and cortisol are toxic to the hippocampus and impair cognition. Associations among these factors have been found in a variety of human conditions, including psychiatric illness and normal aging. These mechanisms are plausible in schizophrenia, which is characterized by a degree of cortisol dysregulation, hippocampal abnormality, and cognitive impairment. Characterization of the role of the stress cascade in schizophrenia has implications for novel pharmacologic and other treatment, especially for cognitive symptoms, which are debilitating and largely refractory to treatment.

Psychotic symptoms in posttraumatic stress disorder

Recent data suggest that the presence of psychotic symptoms in patients suffering from posttraumatic stress disorder (PTSD) may represent an underrecognized and unique subtype of PTSD. Among combat veterans with PTSD, 30% to 40% report auditory or visual hallucinations and/or delusions. The presence of psychotic symptoms in PTSD is associated with a more severe level of psychopathology, similar to that of chronic schizophrenia. In this review, the differential diagnosis of psychotic symptoms in PTSD is discussed, including possible comorbid schizophrenia, psychotic depression, substance-induced psychosis, and personality disorder. A recent biologic study supporting the existence of a unique subtype of PTSD with psychotic features is also addressed, as are the similarities between PTSD with psychotic features and psychotic depression disorder. Finally, data on the treatment implications of psychotic symptoms in PTSD are presented. The intriguing recent findings on psychotic symptoms in PTSD need further investigation in noncombat-related PTSD populations before findings can be generalized to all individuals with PTSD.