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Biomedical subjects

C P O'Brien

Publications and source records attributed to C P O'Brien.

At least 109 records · Page 6Linked to original sources
PubMed1992

Conditioned responses to cocaine-related stimuli in cocaine abuse patients.

Subjects with a history of free-basing and smoking cocaine but no history of opiate injections were exposed to three sets of stimuli. They received cocaine-related stimuli in one session, opiate-related stimuli in a second session, and non-drug stimuli on a third occasion. Compared to the opiate and non-drug cues, the cocaine-related events caused reliable decreases in skin temperature and skin resistance, and reliable increases in heart rate, self-reported cocaine craving, and self-reported cocaine withdrawal. Furthermore, control subjects lacking a history of cocaine or opiate use failed to show such differential responding. These results suggest that cocaine-related stimuli evoke Pavlovian conditioned responses in cocaine abuse patients. Such findings encourage continuing efforts to develop drug treatment strategies based on conditioning principles.

Adult↗
PubMed1992

Conditioned tolerance in human opiate addicts.

Repeated administration of opioid drugs results in tolerance, a lessening of the drug's effect. There is pre-clinical evidence suggesting a conditioning component to drug tolerance. In the present study, six former opiate dependent subjects received i.v. opiate either by un-signalled infusion or by signalled self-injection and the effects were compared with those of saline under double-blind conditions. The subjects' pre-injection rituals constitute a signal which reliably predict the appearance of the opiate. These rituals produced drug-opposite physiological responses which resulted in an attenuation of the effects of the drug. Thus, tolerance was observed when the subjects injected the opiate, but not when the same dose was received by un-signaled intravenous infusion. These results are consistent with a conditioning explanation for the observed drug tolerance.

Adult↗
PubMed1992

Amantadine may facilitate detoxification of cocaine addicts.

The effectiveness of amantadine hydrochloride was evaluated in a double-blind placebo controlled drug trial. The subjects were 42 cocaine dependent men enrolled in a day hospital program. Twenty-one patients were prescribed 100 mg/bid of amantadine to be taken over 10.5 days and 21 were prescribed an equivalent amount of placebo. The primary outcome measures were the Addiction Severity Index at 1 month after study entry and urines during the drug trial (end of weeks 1 and 2) and 1 month after study entry. Urines obtained at the end of the drug trial (2 weeks) indicated that the subjects receiving amantadine (93%) were more likely (P = 0.040) to be free of cocaine than the placebo (60%) subjects. Urine toxicology data at 1-month follow-up again indicated that more of the amantadine subjects (83%) were free of cocaine than the placebo (53%) subjects (p = 0.049); although no differences were found in self-reports of cocaine or other substance use in the past 30 days. The urine findings provided preliminary indication that amantadine may have some effectiveness in reducing cocaine use in cocaine dependent patients.

Adult↗
PubMed1992

A new measure of substance abuse treatment. Initial studies of the treatment services review.

This paper describes the development and initial testing of the Treatment Services Review (TSR). The TSR is a 5-minute, technician-administered interview that provides a quantitative profile of the number and types of treatment services received by patients during alcohol and drug abuse rehabilitation. Test-retest studies indicated satisfactory reliability administered either in person or over the phone. Tests of concurrent validity showed the ability to discriminate different levels of treatment services and good correspondence with independent measures of treatment provided. While additional studies are still needed with this instrument, the data collected thus far suggest that the TSR may serve two types of needs. First, at the programmatic level, the TSR may prove useful in describing and comparing programs in terms of the nature and number of services actually delivered to patients. At the individual patient level, the TSR may offer a means of evaluating the "match" between a patient's needs and the services actually provided.

Comprehensive Health Care↗
PubMed1992

A learning model of addiction.

Repetitive use of psychoactive drugs produces a variety of learned behaviors. These can be classified in the laboratory according to an operant/classical paradigm, but in vivo the two types of learning overlap. The classically conditioned responses produced by drugs are complex and bi-directional. There has been progress in classifying and predicting the types of conditioned responses, but little is known of mechanisms. New techniques for understanding brain function such as micro-dialysis probes in animals and advanced imaging techniques (PET and SPECT) in human subjects may be utilized in conditioning paradigms to "open the black box." Because the existence of conditioned responses in drug users is now well-established, clinical studies have been instituted to determine whether modification of conditioned responses can influence clinical outcome. A recently completed study in cocaine addicts has produced evidence that outcome can be improved by a passive extinction technique over an 8 week outpatient treatment program.

Affect↗
PubMed1992

Cocaine abuse.

Explore the source record for details and available documents.

Cocaine↗
PubMed1991

Risk factors for needle sharing among methadone-treated patients.

OBJECTIVE: This paper examines the sociodemographic and psychiatric characteristics of patients taking methadone who continue to share needles. METHOD: Three hundred twenty-three patients were recruited from four methadone programs. Data were collected by using questionnaires and interviews. Psychiatric symptoms were measured with the SCL-90, the Beck Depression Inventory, and the Addiction Severity Index. RESULTS: Twenty percent of these subjects reported sharing needles within the previous 6 months. Those who shared reported greater difficulty in acquiring new needles, more legal difficulties, more severe drug problems, and higher levels of psychiatric symptoms. CONCLUSIONS: These data suggest that patients who continue to share needles are a more disturbed subgroup of the methadone maintenance population. Efforts designed to reduce needle sharing may need to be more sharply focused on patients who are at greatest risk of infection, and these patients may require more intensive psychiatric services.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Addressing psychiatric comorbidity.

Research studies indicate that addressing psychiatric comorbidity can improve treatment for selected groups of substance-abusing patients. However, the chances for implementing the necessary techniques on a large scale are compromised by the absence of professional input and guidance within programs. This is especially true in public programs, which treat some of the most disadvantaged, disturbed, and socially destructive individuals in the entire mental health system. One starting point for upgrading the level of knowledge and training of staff members who work in this large treatment system could be to develop a better and more authoritative information dissemination network. Such a system exists in medicine; physicians are expected to read appropriate journals and to guide their treatment decisions using the data contained in the journals. Standards of practice and methods for modifying current practice are within the tradition of reading new facts, studying old ones, and comparing treatment outcome under different conditions with what is actually being done. No such general system of information-gathering or -sharing exists, particularly in public treatment programs. One of the most flagrant examples of this "educational shortfall" can be found among those methadone programs that adamantly insist on prescribing no more than 30 to 35 mg/day for all patients, in spite of the overwhelming evidence that these dose levels generally are inadequate. In some cases, program directors are unaware of studies that have shown the relationship between dose and outcome. In other cases, they are aware of the studies but do not modify their practices accordingly. This example of inadequate dosing is offered as an example of one situation that could be improved by adherence to a system of authoritative and systematic information dissemination. Many issues in substance abuse treatment do not lend themselves to information dissemination as readily as that of methadone dosing. However, the existence of a general information/education system about substance abuse treatment, combined with adherence to it among care providers, not only would provide helpful data for treatment staff but also might stimulate their curiosity and initiative. These later qualities, along with additions to existing treatment resources, may in the long run serve as the best guarantee for improvement. and maintenance of quality care.

Humans↗
PubMed1991

Are there minimum conditions necessary for methadone maintenance to reduce intravenous drug use and AIDS risk behaviors?

Although methadone maintenance is a treatment modality with the demonstrated ability to reduce IV drug use and subsequent AIDS risk, methadone maintenance programs vary widely in their effectiveness: Demographically similar patient samples show profound improvements in some programs and little change in others. This suggests that programmatic factors rather than patient variables or sheer availability of methadone may be important active ingredients in effective methadone maintenance. The AIDS epidemic has led to the demand for increased availability of methadone, with suggested elimination of counseling, urine contingencies, and other rehabilitative services in an effort to fund additional "methadone-only" treatment slots. The data reviewed here, including preliminary results from a study examining the effectiveness of "minimal" methadone services, suggest that merely increasing the availability of methadone in the absence of administrative counseling, and rehabilitative services may not adequately protect the majority of patients from continued drug use and the risk of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Integrating systemic cue exposure with standard treatment in recovering drug dependent patients.

Repeated drug administration readily produces classically conditioned responses in animal and human experimental studies. The majority of patients applying for treatment of drug dependence show both autonomic and subjective responses when exposed to drug-related stimuli. These responses are presumed to have been conditioned during a period of active drug use, persist after traditional treatment for drug dependence, and may constitute one of several factors which predispose to relapse. Preliminary data are presented from a novel treatment approach which is designed to test whether drug-conditioned responses can be reduced or extinguished by systematic exposure to drug-related cues and whether such extinction improves the overall results of treatment.

Adult↗
PubMed1990

The opioids: abuse liability and treatments for dependence.

The opioids vary greatly in addictive potential, from the highly addictive such as heroin to the opioid antagonists such as naltrexone, which can be used to treat opioid dependence and overdose. The various opioid compounds have different euphorigenic properties and also produce withdrawal syndromes of distinct patterns of duration and intensity. Dependence liability is affected by both the pleasure-seeking motives for initiating drug use and the painful consequences of abstinence or withdrawal. Detoxification, which takes 7-10 days for the short-acting opioids, is usually the first stage in treatment. Methadone is often used as a preliminary stage in detoxification, but some patients are maintained on methadone for years, since it allows them to lead relatively normal lives. Non-opioid drugs used to control withdrawal symptoms include clonidine. After detoxification, naltrexone, a long-acting opioid antagonist, can be administered orally to prevent relapse.

Humans↗