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Biomedical subjects

Thomas G Brown

Publications and source records attributed to Thomas G Brown.

13 recordsLinked to original sources
PubMed2007

Neurocognitive characteristics of DUI recidivists.

Individuals who drive under the influence (DUI) of alcohol may be at greater risk for neurocognitive impairment because of their exposure to multiple sources of neurological risk. This could contribute to the persistence of DUI behaviour and influence the effectiveness of remedial interventions. The objectives of this study were to clarify the neurocognitive characteristics of DUI recidivists and the nature of potential impairments, and to explore relationships between these characteristics and the frequency of past DUI convictions. One hundred male recidivists were evaluated for visuospatial constructional abilities and visual memory, verbal fluency, attention skills, cognitive flexibility, spatial planning, and verbal and movement inhibition. Results indicated that a majority of recidivists showed signs of neurocognitive impairment on several dimensions. Impairment was most marked on visuospatial constructional abilities and visual memory. In contrast to previous studies, no participants were found to have impulse control problems. Measures of memory and cognitive efficiency were significantly associated with the frequency of past convictions. Finally, exploratory analyses of two potential sources of impairment, alcohol exposure and head trauma, suggested the role of excessive alcohol use as the most obvious associated factor. Overall, the findings indicate that neurocognitive impairments are a common feature in recidivists and may contribute to DUI persistence. Development of a DUI-specific neurocognitive assessment and greater understanding of how neurocognitive status influences DUI risk could lead to remediation strategies better adapted to the individual characteristics of recidivists.

Adult↗
PubMed2007

Stress birefringent, space-variant wave plates for vortex illumination.

We describe the use of stress birefringence in the creation of vortex illumination. A trifold symmetric stress pattern will provide an annular region that exhibits polarization vortices when illuminated with linearly polarized light and scalar vortices when illuminated with circularly polarized light. A finite element plane-stress model is used to analyze the space-variant anisotropy.

Journal Article↗
PubMed2006

Dark-field imaging with cylindrical-vector beams.

Dark-field illumination provides an imaging mode that rejects specular light, thereby highlighting edge features. We analyze dark-field imaging by using cylindrical vector beam illumination with a confocal microscope equipped with a microstructure fiber mode filter. A numerical model based on rigorous coupled-wave analysis has been used to analyze the method. We acquired images of separated edges features to investigate the edge separation resolution of the method. A through-focus comparison of azimuthal and radial polarization shows a measurable dependence of edge separation on polarization.

Algorithms↗
PubMed2005

Salivary cortisol: a predictor of convictions for driving under the influence of alcohol?

AIMS: To examine the relationship between salivary cortisol and frequency of past driving under the influence of alcohol (DUI) convictions. METHODS: A total of 104 males with previous DUI convictions (from one to eight) and mean age of 44.7 years were assessed on measures characterizing repeat DUI offenders, including sociodemographic information, alcohol use behaviours, biological indices of the organic consequences of chronic abuse, negative consequences of excessive drinking, past DUI conviction history, impulse control, and antisocial behaviour tendencies. Saliva samples were taken approximately every 30 min over a 6 h period during an exhaustive multidimensional assessment protocol, and were then assayed to obtain cortisol responses. RESULTS: Blunted cortisol response, typically observed in alcoholics and in high-risk non-alcoholics, was associated with increased number of past DUI convictions. This association was particularly pronounced in multiple DUI offenders, and was stronger than, and independent of, other measures of alcohol use severity and chronicity commonly used for DUI assessment. CONCLUSIONS: Cortisol response may be useful in understanding the mediators underlying repeat DUI offending and the frequent failure of intervention efforts in curbing DUI behaviour.

Accidents, Traffic↗
PubMed2005

Motivational interviewing and clinical psychiatry.

OBJECTIVES: Our objectives were as follows: (1) to survey the literature on motivational interviewing (MI), "a client-centered yet directive method for enhancing intrinsic motivation to change by exploring and resolving client ambivalence" and a well-established method of brief intervention, especially in the field of addictions treatment; (2) to review hypotheses about its mode of action; and (3) to discuss its possible impact on clinical psychiatry, in particular, on teaching communications skills. METHOD: Literature reviews and metaanalyses of numerous clinical trials of MI for addictions treatment have already been published and are briefly summarized. So far, no literature survey exists for MI applied to psychiatric patients. This review is limited to a synthesis of the articles relevant to psychiatry and to comments based on our team's experiences with MI. RESULTS: There is no evidence that MI achieves better results than other established techniques for treating addictions; it may simply work faster. The explanation for the method's rapid effectiveness remains speculative. Outcomes concerning the application of MI to psychiatric patients, although preliminary, are promising. Methods of assessing the integrity of MI treatment are more developed than in most psychotherapies, which permits the learning progress of trainees to be measured. CONCLUSIONS: MI offers a complement to usual psychiatric procedures. It may be worthwhile to teach it, not only for addictions but also for other broad treatment issues, such as enhancing patients' medication compliance and professionals' communication skills. Questions remain concerning MI's feasibility in psychiatry settings.

Cognitive Behavioral Therapy↗
PubMed2005

Motivational interviewing and clinical psychiatry.

OBJECTIVES: Our objectives were as follows: 1) to survey the literature on motivational interviewing (MI), "a client-centered yet directive method for enhancing intrinsic motivation to change by exploring and resolving client ambivalence" and a well-established method of brief intervention, especially in the field of addictions treatment; 2) to review hypothesis about its mode of action; and 3) to discuss its possible impact on clinical psychiatry, in particular, on teaching communication skills. METHOD: Literature reviews and metaanalyses of numerous clinical trials of MI for addictions treatment have already been published and are briefly summarised. So far, no literature survey exists for MI applied to psychiatric patients. This review is limited to a synthesis of the articles relevant to psychiatry and to comments based on our team's experiences with MI. RESULTS: There is no evidence that MI achieves better results than our other established techniques for treating addictions; it may simply work faster. The explanation for the method's rapid effectiveness remains speculative. Outcomes concerning the application of MI to psychiatric patients, although preliminary, are promising. Methods of assessing the integrity of MI treatment are more developed than in most psychotherapies, which permits the learning progress of trainees to be measured. CONCLUSIONS: MI offers a complement to usual psychiatric procedures. It may be worthwhile to teach it, not only for addictions but also for other broad treatment issues, such as enhancing patients' medication compliance and professionals' communication skills. Questions remain concerning MI's feasibility in psychiatry settings.

Humans↗
PubMed2005

Unit culture and research-based nursing practice in acute care.

The purpose of this multiple-case study of research utilization (RU) was to examine whether and how nursing practices in acute-care units are built on research and to identify potential explanations for the observed patterns. Open-ended data were collected from staff nurses and nursing leaders on 8 acute-care units through interviews and observation. RU varied within and across units, but unit culture emerged as the principal factor linked to patterns of RU. Unit-culture themes that formed the links were harmony of research perspective, motivation to learn, goal orientation, creativity, critical inquiry, mutual respect, and maximization of resources. The findings provide a rich description that could serve as a basis for self-assessment of unit culture in inpatient and outpatient acute-care units.

Acute Disease↗
PubMed2003

Stress-induced birefringence in microstructured optical fibers.

We present a numerical study of stress-induced birefringence in microstructured optical fibers (MOFs), using a finite-element method. MOFs under lateral forces and twists are considered separately. Compared with that in standard single-mode optical fibers, stress-induced linear birefringence in MOFs under a lateral force is reduced with increasing air-hole size, whereas twist-induced circular birefringence in MOFs is enhanced when the air-hole size is small.

Journal Article↗
PubMed2003

Rationales, obstacles and strategies for local outcome monitoring systems in substance abuse treatment settings.

The need for outcome monitoring systems (OMS) in substance abuse treatment is now such a pervasive position that it has achieved 'motherhood' stature. Yet, for a variety of reasons, implementation of systematic, ongoing monitoring continues to lag in most settings. The position taken in this article is that a local approach to monitoring is a viable alternative to large scale monitoring programs when such programs are unavailable. Moreover, local OMS can supplement these more generic programs by providing data that are more in tune with the orientation and program development of a specific setting. This article argues that local OMS can be developed with a reorganization of customary documentation procedures, a modest investment of personnel and specialized technical resources, a shorter-term view to outcome, and a commitment to evidence-based treatment.

Cost-Benefit Analysis↗
PubMed2003

Randomization in a substance abuse treatment study: participants who consent vs those who do not.

OBJECTIVE: A mixed research design study compared patients who consented to treatment randomization with patients who opted for usual care. METHODS: Patients in substance abuse rehabilitation who consented to randomization (that is, consenting group [CG]) were compared with those unwilling to undergo randomization (that is, nonconsenting group [NG]) but who, nevertheless, underwent the experimental assessment sessions, which spanned from intake to 6-month follow-up. RESULTS: Patients in the CG exhibited a longer history of drug abuse, less occupational stability at intake, and following intensive treatment, tended not to do as well in terms of recovery, compared with those in the NG. CONCLUSION: Inclusion of data from partial participants in research protocols may offer a viable strategy to better appraise data generalizability.

Adult↗
PubMed2002

Process and outcome changes with relapse prevention versus 12-Step aftercare programs for substance abusers.

AIMS: Presumptive support was sought for mechanisms of action whereby two conceptually distinct aftercare programs, relapse prevention (RP) and 12-Step facilitation (TSF), impact upon substance abusers. PATIENTS AND DESIGN: Adults who had just completed intensive treatment were assigned randomly to either RP (n=61) or TSF (n=70) aftercare programs. SETTING: Three residential treatment facilities. INTERVENTIONS: Trained counselors delivered to small groups a manualized aftercare program which focused either upon the utilization of cognitive-behavioral processes to orchestrate change through an individualized treatment plan (i.e. RP) or which sought to facilitate utilization of AA's 12 Steps (i.e. TSF). MEASUREMENTS: Process measures developed specifically to quantify either: (a) the changes in self-efficacy process in RP or (b) the utilization of AA's principles in TSF, as well as psychosocial and substance abuse indices were administered to all patients pre- and post-aftercare and at 6-month follow-up. FINDINGS: A significant relationship between changes in measures of self- efficacy for RP participants as well as a trend for a relationship between process-specific change for TSF participants partially satisfied the first condition for presumptive support. The fact that the intervention-specific mediators covaried with several outcome indices, and that removal of such mediators attenuated prediction of outcome met, respectively, the second and third conditions for presumptive support. CONCLUSION: Carefully orchestrated RP and TSF aftercare programs yield process changes that are related positively to improved outcome.

Adult↗
PubMedDate not supplied

Matching substance abuse aftercare treatments to client characteristics.

This study investigated matching client attributes to different aftercare treatments. A naturalistic sample of adults entering substance abuse treatment was randomized into either Structured Relapse Prevention (RP, n=61) or a 12-Step Facilitation (TSF, n=72) aftercare program. Four patient attributes were matched to treatment: age, gender, substance abuse profile, and psychological status. Substance use outcomes were assessed 3 and 6 months posttreatment. At 6 months, four significant matches were uncovered. Females and individuals with a multiple substance abuse profile reported better alcohol outcomes with TSF aftercare than their cohorts exposed to RP aftercare. Individuals with high psychological distress at treatment entry were able to maintain longer periods of posttreatment abstinence with TSF aftercare compared to their cohorts exposed to RP. Inversely, RP was found to maintain abstinence significantly longer for individuals reporting low distress compared to those with high distress. Finally, better outcomes were achieved when random assignment to aftercare was consistent with participant preference. Overall, an Alcoholics Anonymous approach to aftercare appears to provide the most favorable substance use outcomes for most groups of substance abusers. RP may be most suitable for clients whose psychological distress is low, especially where maintenance of abstinence is targeted. Where choice in aftercare program is possible, matching client preference with type of aftercare program can improve outcome.

Adult↗