John Thatcher

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BACKGROUND Objective methods of differentiating unipolar versus bipolar depression would enhance our ability to treat these disorders by providing more accurate diagnoses. One first step towards developing diagnostic methodology is determining whether brain function as assessed by functional MRI (fMRI) and functional connectivity analyses might(More)
The primary aim of this functional magnetic resonance imaging (fMRI) study was to test the utility of a paced motor activation task to evaluate frontal-subcortical (FSC) circuit function in bipolar depression. A secondary aim was to determine if utilizing both a motor and cognitive activation paradigm (Stroop) would provide information about the potential(More)
BACKGROUND In major depression, the neural mechanisms underlying suicide related thoughts and behaviors as well as the expression of other depressive symptoms are incompletely characterized. Evidence indicates that both the striatum and cortical midline structures (CMS) may be involved with both suicide and emotional dysregulation in unipolar illness. The(More)
BACKGROUND Compelling evidence suggests abnormal functioning of frontal-subcortical (FSC) circuits in bipolar disorder, but it is unknown whether these are state or trait abnormalities. Longitudinal functional neuroimaging studies may help clarify this issue. However, studies to date have not determined which activation paradigms may be most useful for this(More)
There is considerable evidence of functional abnormalities of the cortico-basal ganglia circuitry in affective disorders. However, it has been unknown whether this represented primary pathology within these circuits or altered activation as a result of aberrant input from other brain regions. The aim of this study was to test the hypothesis that(More)
BACKGROUND Considerable evidence implicates dysfunction of striatal and cortical midline structure (CMS) circuitry in mood disorders. Whether such aberrations exist in bipolar II depression is unknown. METHODS Sixteen unmedicated subjects with bipolar II depression and 19 healthy controls were studied using functional MRI and a motor activation paradigm.(More)
Bipolar II depression is a serious and disabling illness associated with significant impairment and high rates of suicide attempts. However, mechanisms underlying emotional dysregulation in this condition are poorly characterized. The goal of this work was to investigate one component of emotional processing in this disorder, brain activation associated(More)
This project utilized functional MRI (fMRI) and a motor activation paradigm to investigate neural circuitry in euthymic bipolar II disorder. We hypothesized that circuitry involving the cortical midline structures (CMS) would demonstrate abnormal functional connectivity. Nineteen subjects with recurrent bipolar disorder and 18 controls were studied using(More)
The neural processes underlying suicide risk are incompletely characterized. This project utilized functional MRI (fMRI) to determine whether a history of self-harm was associated with striatal circuit function in recurrent major depression in remission. Twenty unmedicated subjects with recurrent major depression and 21 controls were studied using fMRI and(More)
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