Jennifer Bakalar

National Institutes of Health, Bethesda, MD, United States

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Publications (6)35.55 Total impact

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    ABSTRACT: Neuroanatomic studies have not yet addressed how subtle phenotypic distinctions in psychosis alter the underlying brain changes, and whether there is evidence for psychosis as a dimensional construct. We explored the relationship of cortical GM thickness to psychotic phenotypes in children. Cross-sectional comparison of anatomic brain imaging between patients referred as childhood-onset schizophrenia (COS) but ruled out after a drug free inpatient observation. Groups included: patients with no evidence of psychosis (n=22) after drug free observation, patients with psychosis not otherwise specified (PNOS; total n=29) further divided into those without other axis I diagnoses (n=13) and those with other axis I comorbidities (n=16), age/sex matched COS patients (n=48), and 51 matched healthy controls. GM cortical thickness was compared between the groups, and regressed on patients' SAPS, SANS and GAS scores. Patients with no evidence of psychosis showed no cortical GM deficits. Presence of psychosis (PNOS with or without co-morbidities) showed some areas of temporal and prefrontal deficits, more subtle compared to the extensive bilateral cortical deficits seen for COS. GAS SAPS and SANS scores showed a relationship with cortical GM thickness although it did not survive adjustment for multiple comparisons. These results highlight the need for careful phenotypic characterization, as subtle diagnostic distinctions appear to reflect distinct underlying patterns of brain deficits. The incremental nature of cortical deficits from no psychosis to PNOS to COS may further support dimensional model for psychosis.
    Schizophrenia Research 07/2012; 140(1-3):149-54. · 4.59 Impact Factor
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    ABSTRACT: In recent years, transcranial direct current stimulation (tDCS) has been used to study and treat many neuropsychiatric conditions. However, information regarding its tolerability in the pediatric population is lacking. This study aims to investigate the tolerability aspects of tDCS in the childhood-onset schizophrenia (COS) population. Twelve participants with COS completed this inpatient study. Participants were assigned to one of two groups: bilateral anodal dorsolateral prefrontal cortex (DLPFC) stimulation (n = 8) or bilateral cathodal superior temporal gyrus (STG) stimulation (n = 5). Patients received either 2 mA of active treatment or sham treatment (with possibility of open active treatment) for 20 minutes, for a total of 10 sessions (2 weeks). tDCS was well tolerated in the COS population with no serious adverse events occurring during the study. This is the first study to demonstrate that a 20-minute duration of 2 mA of bilateral anodal and bilateral cathodal DC polarization to the DLPFC and STG was well tolerated in a pediatric population.
    Brain Stimulation 10/2011; 4(4):275-80. · 4.54 Impact Factor
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    Molecular Psychiatry 09/2010; · 15.15 Impact Factor
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    ABSTRACT: Little is known about the effects of antipsychotic medications on gray matter (GM) in schizophrenia. Although clozapine remains the most effective antipsychotic medication in treatment-refractory cases, it is unknown whether it has a differential effect on GM development. In an exploratory analysis, we used automated cortical thickness measurements and prospectively scanned childhood-onset schizophrenia (COS) patients who were maintained on one medication. Two atypical antipsychotic medications, clozapine (n=12, 37 scans) and olanzapine (n=12, 33 scans) were compared with respect to effects on cortical development, in contrast to GM trajectories of matched controls. There were no significant differences in the trajectories of cortical thickness between the two treatment groups with the exception of a small circumscribed area in the right prefrontal cortex, where the olanzapine group showed thicker cortex. As expected, both groups showed thinner GM compared to matched controls. Although these analyses do not rule out effects of antipsychotic medications on GM development in schizophrenia, they show no differential effect between clozapine and olanzapine on GM trajectory.
    Schizophrenia Research 11/2009; 116(1):44-8. · 4.59 Impact Factor
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    ABSTRACT: Childhood-onset schizophrenia (COS) is a rare, severe form of the adult-onset illness, with more salient neurobiological causes. Previous cross-sectional structural neuroimaging research has suggested that normal cortical asymmetry patterns [(R-L)/(R+L)] may be altered in adult schizophrenia, although these findings were not well replicated. Recent studies show dynamic changes in brain asymmetry during childhood and adolescence. We hypothesized that COS patients would show a lack of normal development of asymmetry and decreased overall asymmetry. Prospective structural magnetic resonance scans were obtained at baseline and at two-year follow-up visits in 49 right-handed COS patients (mean baseline age: 14.72+/-2.63, 117 scans) and 50 age and sex-matched, right-handed healthy controls (mean baseline age: 15.15+/-3.37, 125 scans). Cortical thickness was calculated at 40,962 homologous points across each cerebral hemisphere using a fully automated, validated method. Differences in developmental asymmetry patterns across the cortical surface were analyzed using a linear mixed effects regression model. No significant asymmetry differences were found either for cross-sectional comparisons of COS and healthy controls across the lateral and medial cortical surfaces or with respect to timing of developmental changes in asymmetry. The present findings do not support asymmetry differences for this severe, early form of schizophrenia.
    Schizophrenia Research 10/2009; 115(1):12-6. · 4.59 Impact Factor
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    ABSTRACT: Clozapine, a dibenzodiazepine antipsychotic, is the most effective medication for treatment-resistant schizophrenia. However, its use has been limited by the high risk of neutropenia. In children, the rate of neutropenia is higher when compared to adults. We decided to explore the use of lithium to manage neutropenia in childhood-onset schizophrenia (COS) through a systematic audit of COS cases. Medical records were reviewed for patients with COS who had been treated with the combination of clozapine and lithium carbonate. Seven patients were found to have been treated with both clozapine and lithium. After initiation of lithium, ANC increased significantly in six out of seven subjects by 29 to 106% with a mean of 66%. In addition, six out of seven subjects continued using both clozapine and lithium for over 2 years (range: 2.0-7.2 years) and do not have immediate plans for discontinuation of either medications. Our study bolsters support for the use of lithium in the management of neutropenia in children treated with clozapine. Although the coadministration of lithium and clozapine appears effective in the management of neutropenia, it is not without its risks and clinicians must be diligent in their joint use of these medications.
    Human Psychopharmacology Clinical and Experimental 09/2009; 24(7):584-9. · 2.10 Impact Factor

Publication Stats

82 Citations
35.55 Total Impact Points


  • 2009–2011
    • National Institutes of Health
      • Branch of Child and Adolescent Psychiatry
      Bethesda, MD, United States
  • 2010
    • National Institute of Mental Health (NIMH)
      • Child Psychiatry Branch
      Maryland, United States