Modification of the punishing effects of psychoactive drugs in rats by previous drug experience.

In Experiment 1, it was shown that chronic prior exposure to amphetamine attenuated the conditioned avoidance of saccharin that was produced by both amphetamine and morphine during gustatory conditioning trials; the relationship between morphine and amphetamine was somewhat anomalous because of their pharmacological dissimilarity. The relationship was also asymmetrical, since in Experiment 2, chronic prior exposure to morphine failed to mitigate avoidance conditioning by amphetamine but was effective in attenuating conditioning by morphine itself. In a third experiment, it was found that prior treatment with chlordiazepoxide attenuated saccharin avoidance conditioned by chlordiazepoxide but not by amphetamine or morphine. The findings were related to Parker, Failor, and Weidman's hypothesis, based on findings with morphine, concerning the development of conditioned preferences for substances associated with the repletion of artificially induced biological needs. It was suggested that the findings were best interpreted as a reflection of drug tolerance rather than conditioned preference.     

Correlates of sensation seeking by heavy, chronic drug users

Product-moment correlations among number of drugs used and several measures of constructs related to sensation seeking were examined for four matched groups of chronic drug users and two supplementary groups of nine persons each. Number of drugs used correlated positively with all scores on the Sensation Seeking Scales, the Extraversion and Neuroticism Scales of the Eysenck Personality Inventory, and the Change Seeker Index. The pattern is consistent with the proposition that a need for stimulation or change underlies experimentation with a large number of chemical substances. The general pattern of correlations among tests resembled that reported by other investigators. The construct validity of the General Score from the Sensation Seeking Scales is enhanced by these findings. The data suggest that this score measures much the same construct as the Change Seeker Index.     

Patterns of adolescent psychoactive substance use and abuse in Benin City, Nigeria

The pattern of use and abuse of psychoactive substances by Nigerian adolescents is investigated. Unlike previous epidemiological studies that used questionnaires to investigate university or postprimary school students, the present study used unobtrusive methods for data collection. The observed pattern of use was not different from that found in previous research. Adolescents tended to use the following drugs in decreasing order of frequency: alcohol, cigarettes, stimulants, cannabis (Indian hemp) and sedative-hypnotics. Polydrug use, especially of alcohol, stimulants, and cigarettes, is common. The use of hard drugs was not reported in this study. The implications of the findings can be appreciated only against the background of the known sequelae (psychological, physical, and socioeconomic) of psychoactive drug abuse. Finally, recommendations for controlling adolescent drug use are offered.     

Neurocognitive correlates of white matter quality in adolescent substance users

Background

Progressive myelination during adolescence implicates an increased vulnerability to neurotoxic substances and enduring neurocognitive consequences. This study examined the cognitive manifestations of altered white matter microstructure in chronic marijuana and alcohol-using (MJ + ALC) adolescents.

Methods

Thirty-six MJ + ALC adolescents (ages 16–19) and 36 demographically similar controls were evaluated with diffusion tensor imaging (Bava et al., 2009) and neurocognitive tests. Regions of group difference in fractional anisotropy (FA) and mean diffusivity (MD) were analyzed in relation to cognitive performance.

Results

In users, lower FA in temporal areas related to poorer performance on attention, working memory, and speeded processing tasks. Among regions where users had higher FA than controls, occipital FA was positively associated with working memory and complex visuomotor sequencing, whereas FA in anterior regions was negatively associated with verbal memory performance.

Conclusions

Findings suggest differential influences of white matter development on cognition in MJ + ALC using adolescents than in non-using peers. Neuroadaptation may reflect additive and subtractive responses to substance use that are complicated by competing maturational processes.     

Determinants of loneliness of young adult drug users

Loneliness is a subjective experience that is influenced by such variables as personality, life experiences, and situation. In the present study, the author examined the connection between the use of ecstasy (MDMA) and the antecedents of loneliness. MDMA users were compared with non-MDMA drug users and with a group of young adults in the general population who did not use drugs. A total of 818 participants from all 3 groups volunteered to answer a 30-item yes-no questionnaire reflecting on their experiences of loneliness and what caused them. Results showed that the predominant causes of loneliness were personal inadequacies, developmental deficits, unfulfilling intimate relationships, relocation or significant separations, and social marginality. There were significant differences between the scores of the MDMA users and scores of the other groups. Gender differences between and within groups were also examined.     

Depression as measured by the Beck Depression Inventory-II among injecting drug users

This study conducts a confirmatory factor analysis of the Beck Depression Inventory-II (BDI-II) with a sample of 598 individuals who reported recent injecting drug use. Findings indicate that out of four models tested, the best model for this sample is a three-factor solution (somatic, affective, and cognitive) previously reported by Buckley, Parker, and Heggie. The findings that nearly 50% of participants provided BDI-II scores indicating significant depressive symptomatology reveals that these individuals are in need of treatment for their psychiatric symptoms as well as substance use. Somatic symptoms are endorsed more strongly than affective or cognitive symptoms of depression, suggesting a possible, but yet poorly defined, relationship between depressive symptomatology and drug use that centers on shared somatic symptomatology.     

Personality characteristics of substance abusers: an MCMI cluster typology of recreational drug users treated in a therapeutic community and its relationship to length of stay and outcome.

The purpose of this investigation was to define homogeneous personality subtypes among substance abusers treated in a long-term, inpatient, drug-free therapeutic community and to determine how the resulting typology was related to length of stay and treatment outcome. A hierarchical agglomerative cluster analysis was performed on the Millon Clinical Multiaxial Inventory (MCMI) scale scores of 235 admissions to a therapeutic community. Five cluster types emerged, which were similar to typologies found in studies with alcoholic inpatients. A concordant solution evolved when a different clustering algorithm was used with the same sample and when clustering was done with a different group of substance abusers. As hypothesized, clusters of patients with average MCMI elevations that indicated avoidant, schizoid, and antisocial qualities tended to stay in treatment fewer days and relapsed earlier during the 1-year follow-up. The implications for substance abuse treatment are discussed.     

HIV prevention among drug users: outcome of a network-oriented peer outreach intervention.

A network-oriented HIV prevention intervention based on social identity theory and peer outreach was implemented for HIV positive and negative drug users. A community sample of 250 were randomly assigned to an equal-attention control condition or a multisession, small-group experimental condition, which encouraged peer outreach; 94% of participants were African American, and 66% used cocaine or opiates. At follow-up, 92% of participants returned, and experimental compared with control group participants were 3 times more likely to report reduction of injection risk behaviors and 4 times more likely to report increased condom use with casual sex partners. Results suggest that psychosocial intervention emphasizing prosocial roles and social identity, and incorporating peer outreach strategies, can reduce HIV risk in low-income, drug-using communities.     

Psychological distress and resilience as risk and protective factors of psychoactive substance use among Chinese nonengaged youth

Nonengaged youth (NEY) are those who have neither been working nor studying for a prolonged period of time. They are at risk of psychoactive substance use, but relevant studies are scarce. Based on a population‐based telephone survey and referrals, we anonymously interviewed 479 Hong Kong Chinese NEY aged 15–24 years. Of them, 14.8–23.7% reported moderate to severe depression, anxiety, and stress. Moreover, one fourth of the participants (24.8%; n = 119) had used psychoactive substances. Adjusted analyses showed that these three psychological distress variables were positively associated with, while resilience was negatively associated with, both ever‐use of psychoactive substances and intention to use such substances in the next 12 months. Loneliness was associated only with intention to use psychoactive substances. The mediating role of psychological distress was shown: Anxiety significantly mediated the association between resilience and ever‐use of psychoactive substances, whereas depression mediated that between resilience and behavioural intention. Resilience was not a significant moderator on the relationship between psychological distress and ever‐use of psychoactive substance use or behavioural intention to use those substances. The findings suggest that anti‐drug interventions should outreach NEY and should include mental health support as well as building up resilience, as NEY are prone to psychological distress that increases risk of substance use.     

A case-control analysis of felony convictions among recreational drug users

This study applied an epidemiologic case-control design to the identification of variables predicting which subjects in a population of recreational drug users were likely to have a felony conviction. A sample of 158 self-identified drug users responded to the web-based DRUGNET survey from February, 1997 through June, 1998. In this sample of 704 U.S. citizens who reported using illicit drugs, 79 (11.2%) reported having a drug-related felony conviction. A further 52 (7.4%) subjects reported felony convictions not related to drugs. Control subjects were drawn from the same sample and matched to cases on sex, age, and ethnicity. Subjects with drug-related convictions differed significantly from controls on 13 variables and those with nondrug-related convictions differed on 11 variables out of the 82 used in this study. Although there are major limitations given the self-selection of the sample, the differences between the groups indicates that we should be wary in generalizing from the minority of drug users who are arrested or incarcerated to the population of drug users in general.     

A randomized clinical trial of a manual-guided risk reduction intervention for HIV-positive injection drug users.

This study randomized 90 HIV-seropositive, methadone-maintained injection drug users (IDUs) to an HIV Harm Reduction Program (HHRP+) or to an active control that included harm reduction components recommended by the National AIDS Demonstration Research Project. The treatment phase lasted 6 months, with follow-ups at 6 and 9 months after treatment entry. Patients in both treatments showed reductions in risk behaviors. However, patients assigned to HHRP+ were less likely to use illicit opiates and were more likely to adhere to antiretroviral medications during treatment; at follow-up, they had lower addiction severity scores and were less likely to have engaged in high risk behavior. Findings suggest that enhancing methadone maintenance with an intervention targeting HIV-seropositive IDUs increases both harm reduction and health promotion behaviors.     

AIDS knowledge among black drug users: an issue of reliability

This study examined the reliability of an inventory measuring AIDS-related knowledge among 553 black drug users. Data were collected from a socially high-risk community in Birmingham, Alabama. The KR-20 reliability scores were computed from the inventory for each drug-use group. The KR-20 reliabilities ranged from .39 to .57. These findings may suggest that the inconsistent reports of the predictive power of AIDS knowledge among drug users reported in previous studies might be related to the low internal consistencies of the inventory.     

Internet access and use among homeless and indigent drug users in Long Beach, California.

There has been a growing interest in using the Internet to access a variety of populations for prevention education and health care. It is not clear that this is viable for homeless and other marginalized populations. The purpose of this study was to describe Internet access and use among a sample of homeless and indigent drug users. A brief questionnaire was developed to assess computer ownership, use, email, and Internet access and use. Participants were recruited through a community-based human immunodeficiency virus (HIV) prevention program. 265 participants completed the questionnaire. While 55% had ever used a computer in their lifetime, only 25% had ever owned a computer, 24% had ever had their own email account, 33% had access to a working computer in the last 30 days, 10% had sent or received email in the last 30 days, and 19% had surfed or accessed information on the Internet in the last 30 days. Logistic regression predicting lifetime use of a computer showed predictive factors of having completed high school (Odds Ratio [OR] = 4.5; 95% Confidence Interval [CI] = 2.41, 8.38) and number of days used amphetamines in the last 30 days, per 5 days of use (OR = 1.64; 95% CI = 1.18, 2.27). Inversely related were age, per 5 years of age (OR = 0.78; 95% CI = 0.65, 0.93) and number of days used marijuana in the last 30 days, per 5 days of use (OR = 0.97; 95% CI = 0.76, 0.99). Very low access and usage suggest that Internet-based public health education models be reexamined for this population. The association with amphetamine use may indicate a facilitating effect of amphetamine by heightening awareness and increasing wakefulness.