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Biomedical subjects

Lon Hays

Publications and source records attributed to Lon Hays.

6 recordsLinked to original sources
PubMed2006

Acute effects of cocaine in two models of inhibitory control: implications of non-linear dose effects.

AIMS: This study examined dose-response effects of oral cocaine on the inhibitory control of behavior in adult cocaine users using two different behavioral models of inhibitory control. DESIGN: Adults (n = 12) with a history of cocaine use performed the stop-signal and cue-dependent go-no-go task to measure inhibitory control of behavior in response to a range of oral cocaine HCl doses (0, 100, 200 and 300 mg). FINDINGS: Although both tasks showed cocaine-induced facilitation of inhibitory control, dose-response functions differed depending on the measures. The stop-signal measure revealed a quadratic dose-response function and the cued go-no-go measure showed a more orderly, linear improvement as a function of dose. CONCLUSIONS: The evidence suggests a two-phasic dose-response in which facilitating effects of stimulant drugs on inhibitory control might be limited to a range of intermediate doses, above which improvement is no longer evident and impairing effects could possibly emerge.

Adult↗
PubMed2006

Psychiatric and pain characteristics of prescription drug abusers entering drug rehabilitation.

There has been intense interest in the problem of prescription drug abuse on the parts of health professionals, law enforcement, the media, and the general public. Clinicians not only need to know how to assess risk but also what drugs are being diverted most in their region. We conducted a prospective survey of prescription drug abusers entering a treatment facility in central Kentucky. Participants (n = 109) were enrolled and completed a structured clinical interview and prescription drug abuse survey. The prescription drug abusers assessed in the study had a mean age of 30.95 years (SD = 10.21), were comprised of 75 men (69%) and 34 women (31%), and were mostly Caucasian (98%). The majority (84%) stated that they had legitimately been given a prescription for opioids for pain at some point from a physician and 61% reported chronic pain concerns. The most commonly abused drugs were hydrocodone-containing formulations (78%) and oxycodone-containing products (69%), while products containing methadone (23%) or fentanyl (7%) were abused much less frequently. Most respondents (91%) stated that they had purchased prescription opioids from a street dealer at least once and the majority (80%) had altered the delivery system of the prescription drug by chewing, snorting, or using i.v. administration. Implications for pain management are discussed, focusing on the need for clinicians treating chronic pain to more thoroughly assess patients for their risk of abuse and addiction before starting an opioid regimen.

Adult↗
PubMed2005

Cocaine improves inhibitory control in a human model of response conflict.

The present study was designed to test the acute effects of cocaine on behavioral control in the presence and absence of motivational conflict. Adults (N = 14) with a history of stimulant use received oral cocaine hydrogen chloride (0, 100, 200, and 300 mg) and performed a cue-dependent go/no-go task to measure inhibitory and activational mechanisms of behavioral control either with or without motivated conflict between the inhibition and the activation of responses. Cocaine improved response inhibition in both conflict conditions, as evident by a decrease in inhibitory failures following active doses. The current study provides a useful model to investigate the effects of other drugs reported to have performance-enhancing effects.

Administration, Oral↗
PubMed2002

Acute effects of oral cocaine on inhibitory control of behavior in humans.

Studies of humans show that individuals with histories of cocaine abuse display reduced inhibitory control over behavioral impulses. The present study tested the effects of oral cocaine on the ability to inhibit behavior in humans. Eight adult volunteers (seven men and one woman) with a history of cocaine abuse participated as in-patient volunteers. Response inhibition and response execution were measured by a stop-signal paradigm using a choice reaction time task that engaged subjects in responding to go-signals when stop-signals occasionally informed them to inhibit the response. Subjects' performance on the task was tested just before and 1 h after a randomized, double-blind administration of 0 mg (placebo), 50, 100, and 150 mg of oral cocaine HCl. Cocaine reduced subjects' ability to inhibit responses to stop-signals. By contrast, no effect of cocaine was observed on the ability to execute responses in terms of their speed and accuracy. Subjective and physiological effects of cocaine were also observed. Together, the findings indicate that acute administration of cocaine can impair the ability to inhibit behavioral responses at doses that do not affect the ability to respond. These findings are important because they identify a specific disinhibiting effect of cocaine that could help explain the documented association between long-term cocaine use and poor impulse control.

Administration, Oral↗
PubMed2002

Developing, implementing, and evaluating a treatment protocol for rural substance abusers.

Substance abuse is a significant social and public health problem facing rural Americans. However, most treatment protocols have been developed in urban areas. This article describes the development, implementation, and evaluation of an innovative substance abuse treatment designed with the collaboration of rural professionals and consumers specifically for rural clients and delivered by rural clinicians. Results of the process evaluation of Structured Behavioral Outpatient Rural Therapy (SBORT) produced findings about the experiences of participating clients, clinicians, and program directors. Most clients perceived SBORT as a helpful learning process that used multiple treatment strategies and presented an alternative to 12-step programs. Clients also reported that treatment was stressful even when beneficial, and that clinician support was critical for remaining in treatment. Most clinicians found that SBORT challenged their "old" treatment frameworks, was demanding to learn and adopt, and that the training and supervision involved in the project implementation helped remedy rural isolation from the treatment community. Interestingly, agency approach to program implementation strongly influenced clinician responses to the innovation. Agency program directors' appraisals of SBORT included observations that the therapy was viable because of its rural-specific design and that most staff were able to adapt to the changes demanded by the manualized protocol. All three groups reported that they saw the emphasis and acceptance of motivation as an emergent process as important to the treatment. This project highlighted the challenge and importance of testing rural substance abuse treatment protocols in naturalistic settings.

Behavior Therapy↗