Adam C. Brooks

Old dogs and new skills: how clinician characteristics relate to motivational interviewing skills before, during, and after training.

OBJECTIVE The relationships between the occupational, educational, and verbal-cognitive characteristics of health care professionals and their motivational interviewing (MI) skills before, during, and after training were investigated. METHOD Fifty-eight community-based addiction clinicians (M = 42.1 years, SD = 10.0; 66% Female) were assessed prior to enrolling in a 2-day MI training workshop and being randomized to one of three post-workshop supervision programs: live supervision via tele-conferencing (TCS), standard tape-based supervision (Tape), or workshop training alone. Audiotaped sessions with clients were rated for MI skillfulness with the Motivational Interviewing Treatment Integrity (MITI) coding system v 2.0 at pre-workshop and 1, 8, and 20 weeks post-workshop. Correlation coefficients and generalized linear models were used to test the relationships between clinician characteristics and MI skill at each assessment point. RESULTS Baseline MI skill levels were the most robust predictors of pre- and post-supervision performances. Clinician characteristics were associated with MI Spirit and reflective listening skill throughout training and moderated the effect of post-workshop supervision method on MI skill. TCS, which provided immediate feedback during practice sessions, was most effective for increasing MI Spirit and reflective listening among clinicians with no graduate degree and stronger vocabulary performances. Tape supervision was more effective for increasing these skills among clinicians with a graduate degree. Further, TCS and Tape were most likely to enhance MI Spirit among clinicians with low average to average verbal and abstract reasoning performances. CONCLUSIONS Clinician attributes influence the effectiveness of methods used to promote the acquisition of evidence-based practices among community-based practitioners.

Cognitive deficits in marijuana users: Effects on motivational enhancement therapy plus cognitive behavioral therapy treatment outcome

Clinical variables that affect treatment outcome for marijuana-dependent individuals are not yet well understood, including the effects of cognitive functioning. To address this, level of cognitive functioning and treatment outcome were investigated. Twenty marijuana-dependent outpatients were administered a neuropsychological battery at treatment entry. All patients received 12 weekly individual sessions of combined motivational enhancement therapy and cognitive behavioral therapy. The Wilcoxon Exact Test was used to compare cognitive functioning test scores between completers and dropouts, and the Fisher Exact Test was used to compare proportion of negative urines between those with higher and lower scores on the cognitive tests. Marijuana abstinence was unrelated to cognitive functioning. However, dropouts scored significantly lower than completers on measures of abstract reasoning and processing accuracy, providing initial evidence that cognitive functioning plays a role in treatment retention of adult marijuana-dependent patients. If supported by further studies, the findings may help inform the development of interventions tailored for cognitively impaired marijuana-dependent patients.

Long acting injectable versus oral naltrexone maintenance therapy with psychosocial intervention for heroin dependence: A quasi-experiment

OBJECTIVE To conduct a quasi-experimental comparison of early clinical outcomes between injectable, sustained-release, depot naltrexone formulation versus oral naltrexone maintenance therapy in individuals with opiate dependence. METHOD Early retention in treatment and urine-confirmed opiate use in the first 8 weeks postdetoxification were compared between patients (diagnosed as opiate-dependent according to DSM-IV criteria) participating in 2 concurrently run randomized clinical trials of oral (n = 69; patients treated from September 1999 to May 2002) and long-acting injectable (n = 42; patients treated from November 2000 to June 2003) naltrexone maintenance therapy with psychosocial therapy. RESULTS Long-acting injectable naltrexone produced significantly better outcome than oral naltrexone on days retained in treatment (F(1,106) = 6.49, P = .012) and for 1 measure of opiate use (F(1,106) = 5.26, P = .024); other measures were not significantly different, but differences were in the same direction. In subanalyses, there were interaction effects between baseline heroin use severity and type of treatment. In subanalyses, heroin users with more severe baseline use showed better retention with oral naltrexone maintenance therapy combined with intensive psychotherapy (behavioral naltrexone therapy) as compared to retention shown by severe heroin users treated with long-acting naltrexone injections combined with standard cognitive-behavioral therapy (χ²(1)= 9.31, P = .002); less severe heroin users evidenced better outcomes when treated with long-acting injectable naltrexone. CONCLUSIONS This quasi-experimental analysis provides tentative indications of superior outcomes for heroin-dependent patients treated with long-acting injectable naltrexone compared to oral naltrexone. The finding that heroin users with more severe baseline use achieved better outcomes with oral naltrexone is most probably attributable to the intensive nature of the psychosocial treatments provided and points to the opportunity for continued research in augmenting injectable naltrexone with psychosocial strategies to further improve outcome, especially in individuals with more severe use. The results should be considered exploratory given the quasi-experimental nature of the study.

Betting on Change: Modeling Transitional Probabilities to Guide Therapy Development for Opioid Dependence

This study investigated the process of change by modeling transitions among four clinical states encountered in 64 detoxified opiate-dependent individuals treated with daily oral naltrexone: no opiate use, blocked opiate use (i.e., opiate use while adhering to oral naltrexone), unblocked opiate use (i.e., opiate use after having discontinued oral naltrexone), and treatment dropout. The effects of baseline characteristics and two psychosocial interventions of differing intensity, behavioral naltrexone therapy (BNT) and compliance enhancement (CE), on these transitions were studied. Participants using greater quantities of opiates were more likely than other participants to be retained in BNT relative to CE. Markov modeling indicated a transition from abstinence to treatment dropout was approximately 3.56 times greater among participants in CE relative to participants in BNT, indicating the more comprehensive psychosocial intervention kept participants engaged in treatment longer. Transitions to stopping treatment were more likely to occur after unblocked opiate use in both treatments. Continued opiate use while being blocked accounted for a relatively low proportion of transitions to abstinence and may have more deleterious effects later in a treatment episode. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

The Effect of the Dielectric Layer Thickness on Spectral Performance of CdZnTe Frisch Collar Gamma Ray Spectrometers

The spectral performance as a function of the dielectric layer thickness for several CdZnTe Frisch collar devices was investigated. Seven different planar bar shaped detectors were fabricated from Redlen Technologies CdZnTe, and many Frisch collar devices were prepared from each planar device. The optimum dielectric layer thickness was experimentally determined for each device. The result of the optimal thickness study was verified through three-dimensional geometry modeling of the potential and electric field. It is shown that there exists an optimal dielectric layer thickness for best performance for CdZnTe Frisch collar devices with aspect ratios (L/W) greater than 2.5.

Improved techniques for the fabrication of Frisch collar CdZnTe gamma ray spectrometers

New methods, designed for the commercial-scale production of Frisch collar CdZnTe gamma ray spectrometers, are described in detail in the following work. Past methods required considerable skilled labor, were not readily automatable, and batch processing was only supported through a portion of the fabrication process. Advances in dielectric materials technology allow for new processes that readily apply the required dielectric film between the CdZnTe crystal and the conductive collar. The processes use spray or chemical vapor deposition methods to accurately achieve a specific thickness. Furthermore, application of the conductive collar was improved to facilitate commercial manufacturing. Comparisons in device performance are presented between the previous and new methods to illustrate the effectiveness and robustness of the new fabrication method. Parylene N performed well as the dielectric layer, while nickel-based paint, high-purity silver-based paint, and a silver-suspension Electrodag all performed well as the conductive layer, each maintaining spectral performance.

Uniformity of charge collection efficiency in Frisch collar spectrometer with THM grown CdZnTe crystals

A 4.7×4.7×9.5 mm3 Frisch collar device was fabricated from CdZnTe materials grown by the Traveling Heater Method (THM). The device was then characterized through probing with a highly collimated 662 keV gammaray source of 137Cs. In a systematic series of experiments, the detector, at its best design, was probed using a collimated 137Cs source. The results were confirmed through simulating the charge collection efficiency (CCE) maps of the device under the operated condition. It is proved that, unlike the planar configuration, the charge collection efficiency profile along the length of Frisch collar device is considerably improved. It is also shown that enhancement in spectral performance occurs due to the application of the Frisch collar to a planar device. This enhancement is due to the fact that the Frisch collar alters the nonuniform CCE profile in a planar device to a more uniform distribution in a Frisch collar device. Additionally, a technique to optimize this uniform distribution is investigated for a 5.0 × 4.7 × 19.6 mm3 Frisch collar device, while the experimental results are confirmed though numerical simulation. Based on this technique, there exists an optimum dielectric layer thickness for the CdZnTe Frisch collar device, for which the CCE profile has its best (most uniform) distribution and shows its best spectroscopic performance. The CdZnTe materials for this study were grown by THM at Redlen Technologies and the CdZnTe devices were fabricated and characterized at the S.M.A.R.T. Laboratory at Kansas State University.

Improved Techniques for the Fabrication of Frisch Collar CdZnTe Gamma Ray Spectrometers

New methods, designed for the commercial-scale production of Frisch collar CdZnTe gamma ray spectrometers, are described in detail in the following work. Past methods required considerable skilled labor, were not readily automatable, and batch processing was only supported through a portion of the fabrication process. Advances in dielectric materials technology allow for new processes that readily apply the required dielectric film between the CdZnTe crystal and the conductive collar. The processes use spray or chemical vapor deposition methods to accurately achieve a specific thickness. Furthermore, application of the conductive collar was improved to facilitate commercial manufacturing. Comparisons in device performance are presented between the previous and new methods to illustrate the effectiveness and robustness of the new fabrication method. Parylene N performed well as the dielectric layer, while nickel-based paint, high-purity silver-based paint, and a silver-suspension Electrodag all performed well as the conductive layer, each maintaining spectral performance.

Preliminary results of KSU Frisch-collar CZT array

Cadmium zinc telluride (CdZnTe or CZT) is a well-known problematic material once dimensions exceed ∼1cm∧3, due to material imperfections that cause severe charge carrier (hole) trapping, compromising the energy resolution for basic planar detector designs. Advances in CZT detector design at Kansas State University (KSU) have demonstrated that room-temperature energy resolution less than 0.9% for 662 keV gamma rays can be consistently achieved. The Frisch-collar detector, developed at KSU, is a design based on the Frisch grid effect, which changes a basic planar detector from a low-resolution device into a high-resolution device by suppressing deleterious effects from charge carrier (hole) losses. We studied the application of Frisch-collar CZT detectors to hand-held or remotely-deployable rapid spectroscopic devices, designed to operate in signal-summation and Compton-suppression modes, employed for greater counting efficiency and improved energy resolution, respectively. The array is made from small volumes of Frisch-collar CZT, lowering cost and easing purity requirements for ingot growth. Timing resolution for signals arising from Compton-scattered gamma rays as a function of detector bias voltage will be discussed.

Effect of crystal length on CdZnTe frisch collar device performance

In this study, the impact of crystal length on CdZnTe Frisch collar detector spectroscopic performance is investigated. Four different Frisch collar devices were designed to have identical aspect ratios of 2.0 for simulation purposes, and all four devices were later fabricated and tested. Pulse height spectra were acquired from all Frisch collar devices with a 137Cs gamma-ray check source and the results are presented. The Frisch collar alters the weighting potential within a planar device and improves the charge collection efficiency (CCE) distribution. Thus, the parameters affecting these distributions have a great impact on the pulse height spectrum, and among those is aspect ratio (AR). All four tested devices have similar aspect ratios, and therefore also have similar weighting potential distributions. However, due to trapping effects, the CCE profiles are not the same, and shorter devices show more uniform responses to gamma rays. CCE simulations confirm that the Frisch collar device with the longest drift length has the lowest performance.