Cross-study comparisons of self-reported alcohol consumption in four clinical groups

Research Note: What If We're Wrong? Some Possible Implications of Systematic Distortions in Adolescents' Self-Reports of Sensitive Behaviors

Research in the social sciences is inherently plagued by the problem of biased or distorted self-reports of sensitive information. Participants in studies, when asked to provide truthful information about their own sensitive behaviors, might distort their responses because of self-presentation concerns or fear that their responses may not actually be completely anonymous or confidential. Researchers who study substance use and other problem behaviors must recognize the possibility that their findings may contain systematic distortions, must try to reduce such biases whenever possible, and must acknowledge them as limitations when little else can be done. This paper was written from the premise that systematic distortion is present in self-reports of substance use and other sensitive behaviors. We consider some of the most widely accepted theories and models from the fields of substance use and problem behavior from the perspective of this premise. Our purpose is not to suggest that these theories or findings are unfounded, but rather that the implications of systematic distortion for this field should be seriously considered when evaluating the validity of research findings and theory.

Effects of aging on frontal white matter microstructure in alcohol use disorder and associations with processing speed

OBJECTIVE

The number of older adults with alcohol use disorder (AUD) is expected to significantly increase in the coming years. Both aging and AUD have been associated with compromised white matter microstructure, although the extent of combined AUD and aging effects is unclear. This study investigated interactions between aging and AUD in cerebral white matter integrity using diffusion tensor imaging (DTI).

METHOD

All participants (44 recently detoxified participants with AUD and 28 healthy controls; ages 31-64 years) completed neurocognitive testing and a DTI scan. Regions of interests were identified on Tract-Based Spatial Statistics images. Hierarchical multiple regression was used to examine interactions between age and AUD status on DTI values [e.g., fractional anisotropy (FA)].

RESULTS

Significant Age × AUD interactions were found across several prefrontal white matter regions (R(2)Δ = 5%-9%). Regional FA was negatively associated with age in the AUD group (rs = -.33 - -.53) but not in the control group (rs = .18 - -.32). This pattern remained after adjusting for lifetime history of drinking and recent drinking. Lifetime alcohol consumption negatively correlated with frontal white matter integrity in the AUD group (rs = -.33 - -.40). Finally, processing speed was significantly slower in the AUD group versus controls (p = .001) and was positively correlated with FA values in frontal white matter regions (rs = .34-.53).

CONCLUSIONS

Cumulative alcohol consumption may affect frontal white matter integrity, and persons with AUD may be more prone to reductions in frontal white matter integrity with advancing age. These reductions in frontal white matter integrity may contribute to reductions in processing speed.

Callosal white matter microstructural recovery in abstinent alcoholics: a longitudinal diffusion tensor imaging study

BACKGROUND

Previous neuroimaging studies of recently detoxified alcohol-dependent patients (RDA) have found significant loss of white matter integrity associated with the shrinkage of the frontal lobes and thinning of the corpus callosum, especially the genu. The current study hypothesized that, in addition to exhibiting the most microstructural white matter disruption in RDA, the genu will also evidence the most recovery after abstinence. This microstructural recovery will be associated with improvements in executive functioning measures.

METHODS

Fifteen RDA were examined approximately 2 weeks after abstinence and again after 1 year of abstinence and compared to 15 age- and education-matched nonalcoholic controls using diffusion tensor imaging (DTI). The effects of group, time, and their interactions on fractional anisotropy, radial diffusivity, and axial diffusivity were evaluated with repeated measures MANOVA; in addition, 2 × 2 ANOVA was used to test changes in measures of executive functioning in the 2 groups.

RESULTS

At 2 weeks of abstinence, DTI of RDA showed significantly lower fractional anisotropy and greater radial diffusivity compared to controls in the genu and body of the corpus callosum. Reexamination after 1 year showed significant time by group interaction with fractional anisotropy increasing and radial diffusivity decreasing in RDA but not controls in these 2 regions. A smaller relapsed group did not show improvements between the 2 time points. Abstinent RDA also showed improvement on Digit Span Backward, a measure of working memory, but did not benefit from practice effects on the Halstead Category Test compared to controls.

CONCLUSIONS

The results suggest susceptibility of the genu and body of the corpus callosum to the effects of alcohol, and the potential for recovery of both these regions after abstinence, perhaps via mechanisms involving myelin reconstitution.

Frontal white matter integrity predictors of adult alcohol treatment outcome

BACKGROUND

Previous research has associated abnormalities in frontal lobe functioning with alcohol relapse. In this study, we used diffusion tensor imaging to investigate whether frontal white matter integrity measured at the start of treatment differs between persons with alcohol use disorders (AUD) who sustain treatment gains and those who return to heavy use after treatment.

METHODS

Forty-five treatment-seeking AUD inpatients and 30 healthy control subjects were included in the study. Six months after completing treatment, 16 of the AUD participants had resumed heavy use (RHU) and 29 others remained abstinent or drank minimally (treatment sustainers [TS]). Voxel-wise group comparisons (TS vs. RHU) were performed on fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity maps generated from each subject's diffusion tensor imaging scan at the start of treatment.

RESULTS

We found significantly lower FA and significantly higher RD in the frontal lobes of the RHU group, relative to the TS group. The RHU group data are consistent with previous reports of abnormal frontal white matter tract abnormalities in persons with AUD.

CONCLUSIONS

It is possible that the lower FA and higher RD in the RHU group reflect microstructural injury to frontal circuitries, and these may underlie the reduced cognitive control amid heightened reward sensitivity associated with resumption of heavy drinking.

Psychopathology and alcohol consumption among treatment-seeking alcoholics: a prospective study

The association between psychopathology and alcohol consumption was studied in a nation-wide representative sample of inpatient alcoholics (n = 245) who were examined at intake and 15 months later. As regards baseline observations men and women with antisocial personality disorder or cognitive impairment had consumed more alcohol in the month prior to admission than those not so affected. In contrast, men with panic disorder drank less compared with those not so affected. The prognosis for men consuming more than the median amount of alcohol was worse than that of women. However, after controlling for psychiatric distress and alcohol consumption at baseline, the prognosis of women was worse. Women but not men who had stopped drinking had a higher degree of psychiatric distress at follow-up compared with those still drinking at a low level. Regarding the prognostic significance of psychiatric disorders at baseline, among men panic disorder predicted continued drinking. Psychiatric distress and alcohol consumption at baseline interacted in the prediction of alcohol consumption at follow-up. The study highlights the importance of a thorough assessment of psychopathology and course of drinking when evaluating the outcome of alcoholism treatment.