Age at initial onset of depression and waking EEG variables in the elderly.
ABSTRACT Depressive illness with initial onset after age 60 has different clinical and prognostic features compared to depression beginning at a younger age. We evaluated waking electroencephalograms (EEGs) in 61 elderly depressed patients (32 early onset, 29 late onset) without cognitive impairment and not receiving psychotropic medications. The groups were comparable for age, severity of Hamilton depression score, education, and Folstein Mini-Mental State scores. Conventional visual EEG analysis revealed no significant differences in the mean alpha rhythm, incidence of abnormal records, or types of EEG abnormalities. Computerized spectral EEG analysis was also performed in 48 patients (23 early onset, 25 late onset). There were no significant differences in the pooled parasagittal mean frequency, theta--beta difference, combined delta and theta percentage, or relative power of the frequency bands. Thus, waking EEGs do not differentiate between elderly patients with the initial onset of the depression before or after age 60.
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ABSTRACT: Because the determinants of anxiety and depression in late adolescence and early adulthood may differ from those in later life, we investigated the temporal stability and magnitude of genetic and environmental correlates of symptoms of anxiety and depression across the life span. Data were collected from a population-based Australian sample of 4364 complete twin pairs and 777 singletons aged 20 to 96 years who were followed-up over three studies between 1980 and 1996. Each study contained the 14-item self-report DSSI/sAD scale which was used to measure recently experienced symptoms of anxiety and depression. Symptom scores were then divided and assigned to age intervals according to each subject's age at time of participation. We fitted genetic simplex models to take into account the longitudinal nature of the data. For male anxiety and depression, the best fitting simplex models comprised a single genetic innovation at age 20 which was transmitted, and explained genetic variation in anxiety and depression at ages 30, 40, 50 and 60. Most of the lifetime genetic variation in female anxiety and depression could also be explained by innovations at age 20 which were transmitted to all other ages; however, there were also smaller age-dependent genetic innovations at 30 for anxiety and at 40 and 70 for depression. Although the genetic determinants of anxiety and depression appear relatively stable across the lifespan for males and females, there is some evidence to support additional mid-life and late age gene action in females for depression. The fact that midlife onset for anxiety occurs one decade before depression is also consistent with a causal relationship (anxiety leading to depression) between these conditions. These findings have significance for large scale depression prevention projects.Twin Research 03/2004; 7(1):39-53. DOI:10.1375/13690520460741435
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ABSTRACT: Brain electrical activity is related to cerebral perfusion. The nature of this relationship is unclear, however and surface-recorded activity has not been a reliable indicator of brain perfusion. We studied 27 subjects, all of whom were examined with single photon emission tomography (SPECT) and quantitative electroencephalography (QEEG), to assess associations between QEEG cordance and relative brain perfusion. Cordance has two indicator states: concordance, which may indicate high perfusion; and discordance, which may indicate low perfusion. We used multiple linear regression to assess the association between cordance and SPECT values, and found that cordance values were strongly associated with tissue perfusion. Concordance in the α band was associated both with mean tissue perfusion and the volume of normally perfused tissue and it had a stronger association with perfusion than any other QEEG variable. Discordance in the β1 band was associated with mean perfusion, and it had a stronger association than did relative but not absolute power. These data suggest that cordance may be useful for the noninvasive assessment of brain perfusion.Psychiatry Research 10/1994; 55(3-55):141-152. DOI:10.1016/0925-4927(94)90022-1 · 2.68 Impact Factor
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ABSTRACT: Electroencephalography (EEG) offers a unique contribution to the armamentarium of imaging technologies used in the evaluation of brain function. The primary clinical application of EEG is in the diagnosis of delirium, dementia, and epilepsy, which are frequently encountered in the practice of geropsychiatry. This review summarizes the principles behind generation of the EEG signal, its strengths and limitations as a technology, clinical indications for performing an EEG, the principles underlying quantitative EEG (QEEG), and how QEEG is allowing us to probe brain function and connectivity in new ways.Journal of Geriatric Psychiatry and Neurology 02/1999; 12(3):150-64. DOI:10.1177/089198879901200308 · 1.63 Impact Factor