Bipolar disorder is common in depressed primary care patients.

OBJECTIVE: To examine the prevalence and treatment of typical and subsyndromal bipolar disorder (BD) in depressed primary care patients. METHODS: Patients with a diagnosis of a mood disorder being treated with antidepressants in 2 academic family practice clinics underwent a structured diagnostic interview (Mini International Neuropsychiatric Inventory) for manic and hypomanic symptoms. RESULTS: Of 58 patients evaluated, 19% met full criteria for bipolar I disorder and 8.6% for bipolar II disorder; 31% had subsyndromal BD (ie, persistent elation or irritability accompanied by additional symptoms of hypomania but not enough symptoms to meet full criteria for bipolar I or II disorder). Only 5 patients with BD were receiving mood stabilizers, which had not been instituted in any patient by the primary care physician. CONCLUSIONS: The high prevalence of patients meeting full criteria for BD and the low rate of identification of BD in primary care patients are consistent with estimates using self-administered questionnaires, but the interview revealed a substantial additional population that could be considered to have subsyndromal BD. Because subsyndromal forms of BD are associated with significant impairment and comorbidity as well as progression to frank BD, recognition of both full and subthreshold BD in primary care practice should be improved.

Functional imaging of hippocampal dysfunction among persons with Alzheimer's disease: a proof-of-concept study.

Cholinergic deficits are an early and functionally significant manifestation of Alzheimer's disease (AD). These deficits contribute to impairment of hippocampally mediated information processing, including declarative memory impairments and abnormal auditory sensory gating. A functional imaging technique that facilitates identification of changes in cholinergically dependent hippocampal information processing would be of considerable use in the study and clinical evaluation of persons with this condition. Techniques that interrogate hippocampal function passively, ie, in a manner requiring no cognitive effort or novel task learning during the neuroimaging procedure, would also be especially useful in this cognitively impaired population. The functional magnetic resonance imaging sensory gating paradigm developed at the University of Colorado, CO, USA, is a functional neuroimaging technique that possesses both of these characteristics. We developed a demonstration project using this paradigm in which we passively interrogated hippocampal function in two subjects with probable AD of mild severity. Imaging data were quick and easy in these subjects and served usefully as an initial demonstration of the feasibility of using this neuroimaging method in this population. Preliminary analyses of the data obtained from these subjects identified abnormal blood oxygen level-dependent responses when compared with four healthy comparators, and the pattern of these responses was consistent with impaired function of the auditory sensory gating network. The strengths and limitations of this neuroimaging paradigm and the additional issues that require investigation in order to continue its development into a research and clinical technique for use in this population are discussed.