Biomedical subjects

Jessica H Kalmar

Publications and source records attributed to Jessica H Kalmar.

4 recordsLinked to original sources

PubMed2006

Processing speed interacts with working memory efficiency in multiple sclerosis.

Information processing speed was assessed using the visual threshold serial addition test (VT-SAT), a computerized modification of the PASAT designed to assess processing speed by controlling for performance accuracy. Persons with MS (N=43) and healthy individuals (N=32) were administered the VT-SAT varying working memory loads (1-back versus 2-back). Results indicated that at the lower working memory load (1-back) all individuals with MS were able to achieve a working memory performance level equivalent to healthy individuals, but required significantly more processing time to do so. In contrast, at the higher working memory load (2-back), about 70% of MS participants were able to achieve a performance level equivalent to healthy individuals, but again required significantly more processing time. The results are discussed in the context of the dynamic nature of the relationship between processing speed and working memory performance, emphasizing the dependence of this relationship on other cognitive and disease-related factors.

Adult↗

PubMed2006

Elevated childhood serotonergic function protects against adolescent aggression in disruptive boys.

OBJECTIVE: This longitudinal study examined whether responsiveness of the neurotransmitter serotonin (5-HT) in childhood predicts adolescent aggression. METHOD: Boys (N = 33) with disruptive behavior disorders who received assessments of central 5-HT function via the prolactin response to fenfluramine between 1990 and 1994 when they were 7 to 11 years old were re-evaluated clinically on average 6.7 years later. RESULTS: After accounting for baseline aggression, early 5-HT function accounted for a significant proportion of variance in adolescent aggression. This prospective relationship of childhood 5-HT function with adolescent aggression (r = -0.71) and antisocial behavior (r = -0.59) was found primarily in adolescents who were aggressive during childhood. Irrespective of childhood aggression, no child with high 5-HT function was particularly aggressive at follow-up. CONCLUSIONS: Low childhood 5-HT function appears important, but not sufficient, for the emergence of adolescent aggression. However, early high 5-HT function may protect against adolescent violence and aggression.

Adolescent↗

PubMed2005

Preliminary evidence for persistent abnormalities in amygdala volumes in adolescents and young adults with bipolar disorder.

OBJECTIVES: Abnormalities in volumes of the amygdala have been reported previously in adolescents and adults with bipolar disorder (BD). Several studies have reported reduced volumes in adolescents with BD; however, both decreases and increases in volumes have been reported in adults with BD. Understanding of potential developmental contributions to these disturbances in morphology of the amygdala has been limited by the absence of longitudinal data in persons with BD. Here we use a within-subject longitudinal design to investigate whether amygdala volume abnormalities persist in adolescents and young adults with BD over a time interval of approximately 2 years. METHODS: Participants included 18 adolescents and young adults: 10 participants with BD I and 8 healthy comparison participants. Amygdala volumes were measured on high-resolution magnetic resonance imaging scans acquired twice for each subject over intervals of approximately 2 years. Amygdala volumes were the dependent measures in a mixed-model statistical analysis to compare amygdala volumes between groups over time while covarying for total brain volume. RESULTS: Amygdala volumes were significantly smaller in adolescents and young adults with BD compared with healthy participants (p = 0.018). The effect of time was not significant. CONCLUSIONS: Although the sample size is modest, this study provides preliminary evidence to support the presence of decreased amygdala volumes in adolescents and young adults with BD that persist during this developmental epoch.

Adolescent↗

PubMed2004

The effect of childhood conduct disorder and cognitive functioning on adolescent substance use.

OBJECTIVE: To assess the impact of childhood conduct disorder (CD) and intelligence quotient (IQ) on later substance use in adolescence. METHODS: Neuropsychological and structured diagnostic evaluations were initially administered to 32 children with disruptive behavior disorder when they were 7-11 years of age. They were then re-evaluated on average 6.7 years later using an array of interviews and rating scales with a focus on substance use. RESULTS: Early CD and IQ scores together accounted for a significant proportion of the variance in later substance use (R2=.248). In addition, there was a significant CD and Verbal IQ interaction (R2=.164) such that high Verbal IQ was linked to increased substance use in adolescents who had childhood CD. CONCLUSION: These data indicate that the presence of conduct disorder may interact with high Verbal IQ during childhood in such a way as to predict later adolescent substance use in disruptive behavior disorder populations.

Adolescent↗