Classification of homogeneous regions of vegetation cover in the State of Rio Grande do Sul, Brazil and its temporal dynamics, using AVHRR GIMMS and MODIS data sets.

This study aimed to classify the homogeneous regions of vegetation cover, which occur in Rio Grande do Sul, formed by clustering of pixels with same pattern of temporal variability of the Normalized Difference Vegetation Index (NDVI) of AVHRR GIMMS and MODIS series and to compare their temporal dynamics. We use K means cluster analysis for defining homogeneous regions, based on the temporal variability of GIMMS (8 km spatial resolution) and MODIS (1 km spatial resolution) NDVI data sets, using monthly images mean from 2000 to 2008 (overlapping period); and we analyzed the annual pattern of NDVI. Accuracy assessment was done with Landsat images. The results show that the temporal variability of GIMMS and MODIS NDVI allows to delimit similar homogeneous regions in order to mapping the main vegetation cover. MODIS series shows a greater detail in the definition of the regions, but with compatibility with those generated by GIMMS. The temporal dynamics show a typical seasonal pattern, with variations of NDVI amplitude between the groups, that allow to monitor phenological changes. The deviations from calibration between times series are linear, which would facilitate a correction in order to construct a long synthetic time series for studies of land cover change.

Early discharge predictors among inpatients crack cocaine users.

INTRODUCTION: High rates of early hospital discharge are often observed in crack cocaine users and are related to adverse outcomes and increased public spending. This study evaluated clinical and sociodemographic factors associated with early treatment discharge among crack users. METHODS: The sample comprised 308 men diagnosed with crack cocaine use disorder (crack only), aged 18 to 65 years, admitted between 2013 and 2017 to a male-only hospital unit to treat substance use disorders. Sociodemographic and clinical data were obtained using the Addiction Severity Index, 6th version, and a Sociodemographic Questionnaire. RESULTS: Early discharge (within 7 days) was significantly associated with lack of own income, insufficient family support, being single, and recent homelessness. Regarding drug use, lower treatment retention was related to younger age of crack use onset, recent alcohol use, and nicotine use. Factors such as age, skin color, and educational level showed no relation to the outcome. CONCLUSION: Our findings suggest that presence of characteristics verifiable at the time of admission may be related to crack users' treatment retention. Identification of these factors can contribute to target interventions in order to improve treatment adherence in crack cocaine users.

Serum BDNF levels increase during early drug withdrawal in alcohol and crack cocaine addiction.

Brain-derived neurotrophic factor (BDNF) is involved in several drug-induced brain neuroadaptations. The impact of withdrawal from substances that have different neurological mechanisms on BDNF levels is unclear. Our goal was to compare serum BDNF levels in inpatients with alcohol or crack cocaine use disorders during the early withdrawal period, and to evaluate the association with substance-related outcomes. We performed a follow-up study with 101 men under detoxification treatment (drug preference: alcohol [n = 37] and crack cocaine [n = 64]). Blood samples were collected on the 1st and 15th days of hospitalization to measure serum BDNF levels. Serum BDNF levels increased during the early stage of withdrawal (28.2 ± 10.0 vs. 32.6 ± 13.3, p < 0.001), similarly in individuals with alcohol and crack cocaine use. In the alcohol group, BDNF levels on the 15th day of hospitalization were negatively correlated with age (r = -0.394, p = 0.023). Delta BDNF levels were also negatively correlated with BDNF on the 1st day of hospitalization (p = 0.011). No significant correlation was found regarding substance-related outcomes. This is the first study to compare BDNF levels in alcohol and crack cocaine users undergoing similar treatment conditions. These findings could be related to clinical improvement after abstinence or even to drug withdrawal itself, decreasing neuronal injury. Furthermore, age may be a crucial factor, hindering the recovery of neuroplasticity in alcohol users.

Prevalence of suicide in cocaine users accessing health services: a systematic review and meta-analysis.

OBJECTIVE: This study reviewed and analyzed the prevalence of suicidal behaviors among cocaine users who sought health services. METHODS: This is a systematic review and meta-analysis of studies published until January 2021. PubMed/MEDLINE, Scopus, Embase, PsycINFO, and LILACS were searched. The inclusion criteria were observational (retrospective or prospective), case-control, and/or cross-sectional reports that contained samples of cocaine users aged over 14 years who were assessed in health facilities or were in treatment. The random-effects model was used to calculate the overall prevalence of suicidal behavior with a 95% confidence interval. Subgroup analysis was conducted to investigate sources of heterogeneity. RESULTS: Twenty articles were included, yielding a total of 2,252 cocaine users. The estimated prevalence was 43.59% (95%CI 31.10-57.38) for suicidal ideation and 27.71% (95%CI 21.63-34.73)for suicide attempts. High heterogeneity was found between studies for both outcomes (I² ≥ 93%), although subgroup analysis considering the quality of the studies showed a significant difference in suicide attempts (p = 0.03). CONCLUSION: : Cocaine use can be considered a risk factor for suicidal behavior, and prevention and early screening measures should be implemented to facilitate adequate treatment.

Drug use and driving behaviors among drivers with and without alcohol-related infractions.

INTRODUCTION: Brazil is one of the countries with the highest rates of alcohol-related traffic infractions, but little is known about the profile of the drivers who commit them. Identifying the characteristics of impaired drivers is essential for planning preventive actions. OBJECTIVE: To compare drug use and driving behavior profiles of drivers with and without alcohol-related infractions. METHODS: 178 drivers stopped at routine roadblocks were assessed by traffic agents who conducted standard roadblock procedures (document verification; request of a breathalyzer test [BT]). Drug use and driving behavior data were collected through semi-structured interviews. Subjects were divided into three groups: drivers who refused the BT (RDs, n = 72), drivers who tested positive on the BT (PDs, n = 34), and drivers who had committed other infractions (ODs, n = 72). RESULTS: The proportion of alcohol use in the last year was higher among RDs (100%) than in the PD and OD groups (97.1% and 72.2% respectively, p < 0.001). Lifetime prevalence of cannabis and cocaine use for the overall sample was 44.3% and 18.2%, respectively. Fewer individuals in the OD group (31.5%) reported having been stopped at roadblocks in the previous year compared to the PDs (55.9%) and RDs (48.6%, p = 0.03). However, a higher proportion of RDs reported drunk driving in the same period (87.5%; PD 69.7%; OD 26.9%; p < 0.001). CONCLUSION: Essential differences among groups were observed. RDs had a higher proportion of alcohol use and drunk driving in the previous year; drivers who fit into this particular group may be unresponsive or less responsive to social deterrence and enforcement actions.

Increased cortisol levels are associated with low treatment retention in crack cocaine users.

BACKGROUND: Dysregulation of the hypothalamic-pituitaryadrenal (HPA) axis has been associated with craving and early relapse among individuals with substance use disorders. However, no association has been postulated regarding treatment retention and prognosis in crack cocaine users. OBJECTIVE: Our aim was to investigate the association between morning salivary cortisol levels and treatment retention in crack cocaine users. METHODS: 44 male crack cocaine users were recruited from a detoxification unit. Saliva collection was performed in the morning of the second treatment day. Substance use profile was assessed using the Addiction Severity Index. RESULTS: The median length of stay in inpatient treatment was 7 days (IQR 3-16). Treatment retention was associated with cortisol levels (r = -0.324; p = 0.032), especially in the group with positive family history. Moreover, treatment retention was correlated with age (r = 0.333, p = 0.027), and number of days of tobacco use (r = 0.332, p = 0.028) and crack use (r = 0.327, p = 0.031). A Cox regression model was performed and showed that inpatients with above normal cortisol levels (≥0.69 µg/dL) presented a worse prognostic related to treatment retention (HR = 2.39, CI95% 1.1-5.1, p = 0.024). CONCLUSION: Several factors could contribute to increased cortisol levels in these patients, e.g. craving, dysregulation of the HPA axis, chronic drug use, stress due to confinement, and substance abstinence. Nevertheless, our findings could guide further studies about new biomarkers in crack cocaine use disorder, since HPA axis dysregulation at the time of treatment admittance may be a prognostic marker for treatment retention.

Predictive factors associated with driving under the influence among Brazilian drug-using drivers.

The incidence of driving under the influence of psychoactive substances (DUI) and its recidivism can be curtailed by the proper identification of specific and predictive characteristics among drug users. In this sense, interpersonal violence (IV), psychiatric comorbidity and impulsivity seem to play an important role in DUI engagement according to previous studies. There are, however, limited data originated from low and middle income countries. In the present study, drug-using Brazilian drivers reporting DUI (n = 75) presented a higher prevalence of bipolar disorders (BD; DUI: 8% vs. non-DUI: 0%, p < 0.001), lower prevalence of obsessive-compulsive disorder (OCD; DUI: 0% vs. non-DUI: 12.6%, p < 0.001), and higher prevalence of childhood trauma (DUI: 65.3% vs. non-DUI: 46.8%, p = 0.022) than those not reporting DUI (n = 79). The evaluation of impulsivity though the Barratt Impulsivity Scale, which give impulsivity scores ranging from 30 to 120, showed higher impulsivity scores in the DUI group (80.4 ± 8) than in the non-DUI group (77.2 ± 10, p = 0.045). In general, subjects were young adults (mean age of 36 ± 9 years), Caucasians (58.4%), not married (61.0%), and with elementary schooling (40.3%) with no significant differences in demographic characteristics between drivers with and without DUI behavior. A multiple Poisson regression model showed that individuals reporting IV as perpetrators and history of childhood trauma were more likely to report DUI (PR: 1.66, 95%CI 1.22-2.7; PR: 1.57, 95%CI 1.02-2.42, respectively). The overlapping of violent situations (childhood trauma, IV and DUI) in some individuals presented here corroborates literature data suggesting that DUI can be an externalizing expression of a range of risky behavior, such as impulsiveness and aggressiveness. Moreover, while BD and higher impulsivity scores seem to act as risk factors for DUI, OCD was shown as a protective factor. These results corroborate the hypothesis that individuals with high risk for DUI could probably be identified by multidimensional assessment of cognitive, risky taking, and personality traits, which perhaps could facilitate the development of focused interventions.

Early discharge predictors among inpatient crack cocaine users

Abstract Introduction High rates of early hospital discharge are often observed in crack cocaine users and are related to adverse outcomes and increased public spending. This study evaluated clinical and sociodemographic factors associated with early treatment discharge among crack users. Methods The sample comprised 308 men diagnosed with crack cocaine use disorder (crack only), aged 18 to 65 years, admitted between 2013 and 2017 to a male-only hospital unit to treat substance use disorders. Sociodemographic and clinical data were obtained using the Addiction Severity Index, 6th version, and a Sociodemographic Questionnaire. Results Early discharge (within 7 days) was significantly associated with lack of own income, insufficient family support, being single, and recent homelessness. Regarding drug use, lower treatment retention was related to younger age of crack use onset, recent alcohol use, and nicotine use. Factors such as age, skin color, and educational level showed no relation to the outcome. Conclusion Our findings suggest that presence of characteristics verifiable at the time of admission may be related to crack users' treatment retention. Identification of these factors can contribute to target interventions in order to improve treatment adherence in crack cocaine users.

Prevalence of suicide in cocaine users accessing health services: a systematic review and meta-analysis

Objective: This study reviewed and analyzed the prevalence of suicidal behaviors among cocaine users who sought health services. Methods: This is a systematic review and meta-analysis of studies published until January 2021. PubMed/MEDLINE, Scopus, Embase, PsycINFO, and LILACS were searched. The inclusion criteria were observational (retrospective or prospective), case-control, and/or cross-sectional reports that contained samples of cocaine users aged over 14 years who were assessed in health facilities or were in treatment. The random-effects model was used to calculate the overall prevalence of suicidal behavior with a 95% confidence interval. Subgroup analysis was conducted to investigate sources of heterogeneity. Results: Twenty articles were included, yielding a total of 2,252 cocaine users. The estimated prevalence was 43.59% (95%CI 31.10-57.38) for suicidal ideation and 27.71% (95%CI 21.63-34.73) for suicide attempts. High heterogeneity was found between studies for both outcomes (I2 ≥ 93%), although subgroup analysis considering the quality of the studies showed a significant difference in suicide attempts (p = 0.03). Conclusion: Cocaine use can be considered a risk factor for suicidal behavior, and prevention and early screening measures should be implemented to facilitate adequate treatment.