Michael H. M. Ling

Bio: Michael H. M. Ling is an academic researcher. The author has contributed to research in topics: Mental illness. The author has an hindex of 1, co-authored 1 publications receiving 315 citations.

Side Effects of Corticosteroid Therapy: Psychiatric Aspects

Abstract: • We reviewed the literature to determine the characteristics of corticosteroid-induced mental disturbances. We conclude that (1) while dosage may be correlated to the risk of developing mental disturbances, neither dosage nor duration of treatment seems to affect the time of onset, duration, severity, or type of mental disturbances; (2) euphoria, depression, and psychotic reactions are the common manifestations of corticosteroidinduced mental disturbances; (3) females seem to be more prone to these disturbances than males; (4) patients with past mental illness are not necessarily predisposed to such disturbances; and (5) corticosteroid-induced mental disturbances are usually reversible on dose reduction or discontinuation of the drug. At present there are no simple models to explain the psychotic reactions, anxiety, or agitation seen in corticosteroidinduced mental disturbances.

Insomnia in the Context of Cancer: A Review of a Neglected Problem

Abstract: This article reviews the evidence on the diagnosis, epidemiology, etiology, and treatment of insomnia in the context of cancer and proposes several areas for future research. Clinical and diagnostic features of insomnia are described and prevalence estimates of insomnia complaints in cancer patients are summarized. Then, potential etiologic factors (ie, predisposing, precipitating, and perpetuating factors) and consequences of insomnia (ie, psychologic, behavioral, and health impact) in the context of cancer are discussed. Finally, pharmacologic and psychologic treatments previously shown effective to treat insomnia in healthy individuals are discussed as valuable treatment options for cancer patients as well. Because long-term use of hypnotic medications is associated with some risks (eg, dependence), it is argued that psychologic interventions (eg, stimulus control, sleep restriction, cognitive therapy) are the treatment of choice for sleep disturbances in the context of cancer, especially whe...

Basal cortisol levels and cognitive deficits in human aging

Abstract: A group of 19 healthy elderly subjects previously shown to differ in terms of their cortisol levels over a 4 year period were administered a neuropsychological test battery assessing memory, attention, and language. Correlational analyses performed on various corticosteroid measures showed that the slope of the change in cortisol levels over time predicted cognitive deficits in this elderly population. Aged subjects showing a significant increase in cortisol levels with years and with high current basal cortisol levels were impaired on tasks measuring explicit memory and selective attention when compared to aged subjects presenting either decreasing cortisol levels with years or increasing cortisol levels with moderate current basal cortisol levels. We further showed that subjects presenting a decrease in cortisol levels with years performed as well as young healthy subjects with regard to cognitive performance. Thus, impaired cognitive performance was associated with recent evidence of hypothalamic-pituitary-adrenal (HPA) dysregulation and elevated basal cortisol levels. These results are consistent with recent animal studies showing the existence of subpopulations of aged rats that differ in HPA activity and cognitive performance. Finally, the pattern of cognitive results related to the cortisol history of subjects is in agreement with a role played by the hippocampus in age-related HPA dysfunction and cognitive performance.

Enduring effects of chronic corticosterone treatment on spatial learning, synaptic plasticity, and hippocampal neuropathology in young and mid-aged rats

Abstract: Prolonged treatment with stress levels of corticosterone has been reported to produce changes in the hippocampus. In the experiments reported here, we examined for functional and morphological consequences of this treatment. First, young adult or mid-aged male Long-Evans rats were treated for either 1 or 3 months with corticosterone, at a dose sufficient to mimic the elevated hormone levels observed following exposure to mild stress. Two weeks following the termination of treatment, the animals were tested in the Morris water maze to assess spatial learning. No behavioral deficits were observed after 1 month of treatment. A 3 month treatment period also had no effect in young rats, but produced a learning impairment in the mid-aged rats. We then examined whether the effect of elevated corticosterone in mid-aged animals could be produced by a physiological stressor. Mid-aged rats were maintained for 6 months under conditions of low or high social stress. Six months of exposure to high social stress produced significant spatial learning impairments in the Morris water maze. These effects were absent in high social stress animals that had been previously adrenalectomized (with low-level corticosterone replacement), suggesting that elevated glucocorticoid levels mediate the effects of stress on spatial memory in older animals. In a final experiment, mid-aged rats were treated with corticosterone at levels that mimicked those naturally occurring at the diurnal peak (medium-B: 12–17 micrograms/dl) or in response to stress (high-B: 25–32 micrograms/dl). Only rats exposed to high levels of corticosterone demonstrated impaired performance in the Morris water maze.(ABSTRACT TRUNCATED AT 250 WORDS)