Bachelor of Science, University of California San Diego (2006)
Doctor of Philosophy, University of Cincinnati (2013)
Leanne Williams, Postdoctoral Faculty Sponsor
Abstract Background: Amygdala volume abnormalities have been reported in relation to craving in substance-dependent adults, but it remains unclear if these effects are seen in adolescent marijuana (MJ) users, particularly following abstinence.The aim of this study was to examine the relationship between amygdala volume and craving during 28 days of abstinence in adolescent MJ users.MJ-using adolescents (n = 22) aged 16-19 were recruited as part of a larger study on brain function in teen drug users. Craving measures were collected twice per week throughout a 28-day abstinence period. High-resolution anatomical magnetic resonance imaging data were collected at the end of the 28 days of confirmed abstinence. Left and right amygdala volumes were traced by hand (ICC > 0.86). Composite scores for self-reported craving and withdrawal symptoms throughout the 28-day abstinence period were calculated to provide four composite measures of total craving, mood, sleep, and somatic complaints.RESULTS revealed that greater craving during abstinence was significantly associated with smaller left and right amygdala volumes, after controlling for age and gender. Other measures of withdrawal, including mood, somatic complaints and sleep problems, were not related to amygdala morphometry.These results are consistent with previous findings in adult alcohol- and cocaine-dependent individuals, who demonstrated a relationship between reduced amygdala volumes and increased craving. Future studies are needed to determine if these brain-behavior relationships are attributable to MJ use or predate the onset of substance use.
View details for DOI 10.3109/00952990.2014.966198
View details for PubMedID 25668330
Alcohol dependence (AD) has global effects on brain structure and function, including frontolimbic regions regulating affective processing. Preliminary evidence suggests alcohol blunts limbic response to negative affective stimuli and increases activation to positive affective stimuli. Subtle gender differences are also evident during affective processing.Fourteen abstinent AD individuals (8 F, 6 M) and 14 healthy controls (9 F, 5 M), ages 23 to 60, were included in this facial affective processing functional magnetic resonance imaging pilot study. Whole-brain linear regression analyses were performed, and follow-up analyses examined whether AD status significantly predicted depressive symptoms and/or coping.Fearful Condition-The AD group demonstrated reduced activation in the right medial frontal gyrus, compared with controls. Gender moderated the effects of AD in bilateral inferior frontal gyri. Happy Condition-AD individuals had increased activation in the right thalamus. Gender moderated the effects of AD in the left caudate, right middle frontal gyrus, left paracentral lobule, and right lingual gyrus. Interactive AD and gender effects for fearful and happy faces were such that AD men activated more than control men, but AD women activated less than control women. Enhanced coping was associated with greater activation in right medial frontal gyrus during fearful condition in AD individuals.Abnormal affective processing in AD may be a marker of alcoholism risk or a consequence of chronic alcoholism. Subtle gender differences were observed, and gender moderated the effects of AD on neural substrates of affective processing. AD individuals with enhanced coping had brain activation patterns more similar to controls. Results help elucidate the effects of alcohol, gender, and their interaction on affective processing.
View details for DOI 10.1111/acer.12626
View details for PubMedID 25684049
Intact cognition is a foundational component of one's ability to be competent to stand trial. Given the cost of assessing and treating incompetence, it is recommended that clinicians develop efficient methods to identify individuals who are most likely to require intensive competence-related treatment interventions. This study sought to ascertain whether a brief cognitive screening instrument, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), could predict the length of stay required to restore trial competency among 288 forensic psychiatric inpatients undergoing competency restoration treatment. Results indicated that incompetent defendants who were older or demonstrated poorer overall RBANS performance required longer hospitalizations to be deemed restored to trial competence. Interestingly, incompetent defendants scoring in the 51-60 range on the RBANS Total Scale Index were almost three times more likely to require hospitalization beyond the average length of stay. Findings support the use of the RBANS to identify individuals early in the treatment process who may require and benefit from intensive restoration treatment.
View details for DOI 10.1080/13854046.2015.1005678
View details for Web of Science ID 000350299000011
View details for PubMedID 25650794