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P A Coble

Publications and source records attributed to P A Coble.

6 recordsLinked to original sources

Concordance between habitual sleep times and laboratory recording schedules.

The validity of laboratory-based studies of sleep depends, in part, upon good concordance between habitual sleep schedule and laboratory recording schedule. Without good concordance, error variance due to the circadian misplacement of sleep and to different amounts of time in bed is probable. In an assessment of scheduling concordance in 1,762 research patient nights over two time intervals, we observed good concordance (< 30-minute discrepancy) in 71.2-77.3% of bedtimes and waketimes, discrepancy (difference of > or = 30 minutes) in 14.9-24.2% of bedtimes and waketimes, and missing data in 4.6-7.5% of times. Waketime differences were consistently in the direction of earlier laboratory than habitual waketimes, whereas differences in bedtime were about equally divided between earlier and later (laboratory vs. habitual). Subjects with schedule discordance averaged 19.5 minutes less time in bed during laboratory sessions as compared with their habitual sleep schedule, whereas subjects with schedule concordance averaged only 3.6 minutes less (p < 0.001). Our experience suggests that it may be more difficult to achieve higher rates of concordance among young adult and middle-aged subjects than among elders and that patient requests related to external constraints on scheduling were a frequent reason for discrepancy. We strongly recommend a policy of routinely including data on laboratory versus habitual sleep times in peer-reviewed publications.

Adult

EEG sleep in primary depression. A longitudinal placebo study.

Characteristic EEG sleep changes in depression are highlighted by a sleep continuity disturbance, delta sleep reduction, and a shortened REM latency. Since these findings have been derived primarily from only a few baseline recordings, questions regarding their persistence and/or variability have not been previously addressed. As part of an extensive set of investigations of EEG sleep in depression, we examined nightly the sleep of 12 hospitalized, non-delusional, primary depressives who were involved in a program of active psychosocial treatment intervention and received only placebo during a 5-week study period. EEG sleep findings revealed a relative lack of change across time, particularly in those parameters reported to be associated with a primary or 'biologic' depressive episode. While some degree of clinical improvement was noted, the group failed to achieve a state of remission or even partial remission as determined by the Hamilton Rating Scale. It appears that the major sleep alterations associated with such disorders persist for up to at least 5 weeks in the absence of pharmacologic or other somatic intervention.

Adult

EEG sleep and affective psychoses: I. Schizoaffective disorders.

The sleep electroencephalogram (EEG) was studied in 41 depressed inpatients. EEG sleep records were compared for two diagnostic subgroups; patients with psychotic depression (n = 29) or with schizoaffective disorders (n = 12). As was true in the previous pilot study, no major EEG sleep variables distinguished the patients with psychotic depression from those with schizoaffective disorders. These data are consistent with the theory that all psychotic depressive states may have certain common psychobiologic features such as shortened rapid eye movement (REM) sleep latency.

Depressive Disorder

Changes in weight during treatment for depression.

Changes in appetite and weight were examined in a group of 47 carefully diagnosed primary depressives who were treated in a random design with either placebo (N = 17) or amitryptyline (N = 30) over a 35-day protocol. While the amitriptyline treated group as a whole showed a greater gain in weight than did the placebo group (4.5 vs. 0.5 lb, p less than 0.05), no differential effects could be demonstrated between drug responders and nonresponders. Likewise, while a consistent relationship between the self-report of decreased appetite and final weight change was noted in the placebo group, no simple relationship between final weight change and self-reported changes in appetite were apparent in the drug-treated patients. There was, however, a relationship between the report of decreased appetite and clinical severity of depression in the drug nonresponder subgroup despite significant weight gain during the protocol. Thus, weight change during this study period did not appear to show a simple relationship to corresponding clinical change. The clinical lore that has supported the notion that increased appetite and weight gain in patients being treated with tricyclic antidepressants are "good" signs cannot be confirmed by our findings.

Adult

Electroencephalographic sleep recordings and depression in the elderly.

Eighteen patients over the age of 60 who were experiencing a major depressive episode were studied on a Clinical Research Unit after they had been drug-free for at least two weeks. All-night electroencephalographic (EEG) recordings revealed considerable fragmentation of sleep, a mean sleep efficiency of 58 percent, and very little delta sleep. The findings of reduced sleep time, shortened REM latency, and high REM density were similar to those in depressed patients under the age of 60. These preliminary findings support the application of EEG sleep recordings as a tool for the differential diagnosis of depression in the elderly.

Aged