Anxiety disorders among methamphetamine dependent adults: association with post-treatment functioning

You are the danger: attenuated insula response in methamphetamine users during aversive interoceptive decision-making

BACKGROUND

Drug dependent individuals often make drug-taking decisions when they do not feel well. Yet, few studies have examined the influence of an aversive state on decision-making related neural processing.

METHODS

We investigate brain activation to decision-making during an aversive interoceptive challenge in methamphetamine users using functional magnetic resonance imaging (fMRI). Recently abstinent inpatients with methamphetamine use disorder (METH; n=20) and healthy comparison subjects (CTL; n=22) performed a two-choice prediction task at three fixed error rates (ER; 20%=reward, 50%=uncertainty, 80%=punishment) while anticipating and experiencing episodes of inspiratory breathing load during fMRI.

RESULTS

METH exhibited higher trait anxiety in conjunction with lower anterior insula (AI) and inferior frontal gyrus (IFG) activation than CTL across trials. METH also showed lower posterior insula (PI) and anterior cingulate cortex (ACC) activation than CTL during breathing load independent of ER. For the crucial ER by interoception interaction, METH displayed lower ACC activation to punishment/loss than CTL during breathing load. Within METH, lower trait anxiety was linked to AI/IFG attenuation across trials.

CONCLUSIONS

AI/IFG attenuations in METH are suggestive of an executive functioning deficit, particularly in users with low anxiety, reflecting reduced resources allocated to choice selection. In contrast, PI/ACC reductions in METH appear specific to impairments in registering and evaluating interoceptive experiences. Taken together, inadequate activation of brain areas that are important for regulating when one does not feel well may be the neural basis for poor decision-making by METH.

Psychiatric disorders in individuals with methamphetamine dependence: prevalence and risk factors

Methamphetamine dependence may be associated with a range of psychiatric disorders. However, relatively few studies have systematically examined these disorders and possible risk factors. This study used a structured diagnostic interview to assess the prevalence and pattern of co-morbid psychiatric disorders in individuals with methamphetamine dependence; and identified risk factors for this comorbidity. One hundred adult volunteers with a diagnosis of methamphetamine dependence and without co-morbid medical disorders were consecutively recruited from three drug rehabilitation centres. Each volunteer was assessed with a socio-demographic questionnaire and evaluated for psychiatric comorbidity using the Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I). A regression model was used to determine predictors of psychiatric comorbidity. Co-morbid psychiatric disorders were present in 36.0% of the sample; these included mood disorders (16.0%), psychotic disorders (13.0%) and anxiety disorders (7.0%). One in four of these disorders were assessed as being substance-induced. Independent predictors of psychiatric comorbidity included being male (OR = 10.04, 95% C.I = 2.07-48.63, p = 0.004), younger (OR = 0.87, 95% C.I = 0.77-0.99, p = 0.04), and having a previous psychiatric disorder (OR = 18.45, 95% C.I = 3.81-89.33, p < 0.001). Mood, psychotic, and anxiety disorders are common in individuals with methamphetamine dependence. Risk factors for such comorbidity can be identified. These findings underscore the need for an integrated model of care addressing both substance use disorders and psychiatric comorbidity.

The association between substance use and common mental disorders in young adults: results from the South African Stress and Health (SASH) Survey

Introduction

Although substance use is commonly associated with mental disorders, limited data on this association are available from low and middle income countries such as South Africa. The aims of the study were i) to determine patterns of substance use in young adults, ii) to identify trends of common psychiatric disorders in relation to use of specific substances, and iii) to determine whether specific psychiatric disorders were associated with use of specific substances in the South African population.

Methods

Data were drawn from the South African Stress and Health (SASH) study, a nationally-representative, cross-sectional survey of South African households that forms part of a World Health Organisation (WHO) World Mental Health (WMH) initiative to standardise information on the global burden of mental illness and its correlates. Data from a subset (n = 1766; aged 18 to 30 years) of the SASH sample of 4351 individuals were analysed. The Composite International Diagnostic Interview Version 3 (CIDI 3.0) was used to elicit basic demographic details and information regarding mental illness and substance use. Multiple regression analyses, adjusted for age and gender, were used to identify associations between mental disorders and substance use.

Results

Significant associations were found between substance use and mood and anxiety disorders, with a particularly strong relationship between cannabis use and mental disorder.

Conclusion

The results are consistent with those from previous studies, and reinforce the argument that comorbid substance use and mental disorders constitute a major public health burden.

Neurologic manifestations of chronic methamphetamine abuse

The drug with perhaps the greatest impact on the practice of Psychiatry is Methamphetamine. By increasing the extracellular concentrations of dopamine while slowly damaging the dopaminergic neurotransmission, Meth is a powerfully addictive drug whose chronic use preferentially causes psychiatric complications. Chronic Meth users have deficits in memory and executive functioning as well as higher rates of anxiety, depression, and most notably psychosis. It is because of addiction and chronic psychosis from Meth abuse that the Meth user is most likely to come to the attention of the practicing Psychiatrist/Psychologist. Understanding the chronic neurologic manifestations of Meth abuse will better arm practitioners with the diagnostic and therapeutic tools needed to make the Meth epidemic one of historical interest only.

Evaluating the impact of community-based treatment options on methamphetamine use: findings from the Methamphetamine Treatment Evaluation Study (MATES)

AIMS

To evaluate the impact of community-based drug treatment on methamphetamine use using inverse probability of treatment-weighted (IPTW) estimators to derive treatment effects.

DESIGN

A longitudinal prospective cohort study with follow-ups at 3 months, 1 year and 3 years. Treatment effects were derived by comparing groups at follow-up. IPTW estimators were used to adjust for pre-treatment differences between groups.

SETTING

Sydney and Brisbane, Australia.

PARTICIPANTS

Participants were methamphetamine users entering community-based detoxification (n = 112) or residential rehabilitation (n = 248) services and a quasi-control group of methamphetamine users (n = 101) recruited from the community.

MEASUREMENTS

Frequency of methamphetamine use between interviews (no use, less than weekly, 1-2 days per week, 3+ days per week), continuous abstinence from methamphetamine use, past month methamphetamine use and methamphetamine dependence.

FINDINGS

Detoxification did not reduce methamphetamine use at any follow-up relative to the quasi-control group. Relative to quasi-control and detoxification groups combined, residential rehabilitation produced large reductions in the frequency of methamphetamine use at 3 months [odds ratio (OR) = 0.23, 95% confidence interval (CI) 0.15-0.36, P < 0.001), with a marked attenuation of this effect at 1 year (OR 0.62, 95% CI 0.40-0.97, P = 0.038) and 3 years (OR = 0.71, 95% CI 0.42-1.19, P = 0.189). The greatest impact was for abstinence: for every 100 residential rehabilitation clients there was a gain of 33 being continuously abstinent at 3 months, with this falling to 14 at 1 year and 6 at 3 years.

CONCLUSIONS

Community-based residential rehabilitation may produce a time-limited decrease in methamphetamine use, while detoxification alone does not appear to do so.

Co-occurring amphetamine use and associated medical and psychiatric comorbidity among opioid-dependent adults: results from the Clinical Trials Network

Background

In response to the rising rate of treatment admissions related to illicit use of amphetamines (eg, methamphetamine), we examined the prevalence of amphetamine use among treatment-seeking, opioid-dependent adults, explored whether amphetamine users were as likely as nonamphetamine users to enroll in opioid-dependence treatment trials, and determined whether amphetamine users manifested greater levels of medical and psychiatric comorbidity than nonusers.

Methods

The sample included 1257 opioid-dependent adults screened for participation in three-multisite studies of the National Drug Abuse Treatment Clinical Trials Network (CTN001-003), which studied the effectiveness of buprenorphine for opioid detoxification under varying treatment conditions. Patients were recruited from 23 addiction treatment programs across the US. Medical and psychiatric comorbidity were examined by past-month amphetamine use (current vs former) and route of administration. Five mutually exclusive groups were examined, ie, nonusers, current amphetamine injectors, current amphetamine noninjectors, former amphetamine injectors, and former amphetamine noninjectors.

Results

Of the sample (n = 1257), 22.3% had a history of regular amphetamine use. Of the 280 amphetamine users, 30.3% reported injection as their primary route. Amphetamine users were more likely than nonusers to be white and use more substances. Amphetamine users were as likely as nonusers to enroll in treatment trials. Bivariate analyses indicated elevated rates of psychiatric problems (depression, anxiety, hallucinations, cognitive impairment, violence, suicidal thoughts/attempts) and medical illnesses (dermatological, hepatic, cardiovascular, respiratory, neurological, seizure, allergy conditions) among amphetamine users. After adjusting for demographic variables and lifetime use of other substances: current amphetamine users and former injectors showed an increased likelihood of having medical illnesses and hospitalizations; current injectors had elevated odds of suicidal thoughts or attempts; current noninjectors exhibited elevated odds of anxiety, cognitive impairment, and violent behaviors; and former noninjectors had increased odds of depression.

Conclusion

Treatment-seeking, amphetamine-using, opioid-dependent adults manifest greater levels of medical and psychiatric morbidity than treatment-seeking, opioid-dependent adults who have not used amphetamines, indicating a greater need for intensive clinical management.

Neurologic manifestations of chronic methamphetamine abuse

Methamphetamine abuse has reached epidemic proportions in the United States. The repetitive use of methamphetamine causes massive and sustained elevations in central monoamines. These elevations, particularly in dopamine, can cause changes in the function of the central nervous system that can manifest as a variety of neurologic disorders. This article focuses on these disorders, such as neurocognitive disorders and mental illness, including drug-induced psychosis; motor disorders, including the possible risk of Parkinson's disease, the development of choreoathetoid movements, and punding; and changes in the physical appearance of the methamphetamine users, including dental caries.