Behavioral sleep medicine. An emerging subspecialty in health psychology and sleep medicine.

As the knowledge base in sleep disorders medicine has broadened, a subspecialty that we will refer to as "behavioral sleep medicine" area is emerging. This article will define this subspecialty area, provide some historical context for its emergence, review issues related to specialty training and clinical practice, and suggest needs for future research.The term "behavioral sleep medicine" was selected because it clearly denoted the two fields from which our subspecialty emerged (health psychology/behavioral medicine and sleep disorders medicine). It suggests much about our approach to training, clinical practice, and research, and it appropriately implies that the field is open to PhD sleep specialists, MD sleep specialists, and other health care providers with the relevant training. Formally, behavioral sleep medicine refers to the branch of clinical sleep medicine and health psychology that: (1) focuses on the identification of the psychological (e.g. cognitive and/or behavioral) factors that contribute to the development and/or maintenance of sleep disorders and (2) specializes in developing and providing empirically validated cognitive, behavioral, and/or other nonpharmacologic interventions for the entire spectrum of sleep disorders.

Chemo- and baroresponses differ in African-Americans and Caucasians in sleep.

To determine sleep effects on baro- and ventilatory responses to transient chemo- and barostimulation in African-Americans and Caucasians, 26 nonobese normotensive young subjects (13 African-Americans and 13 Caucasians) were studied awake and in non-rapid-eye movement (NREM) and rapid-eye-movement sleep during induced transient hypoxemia (N2), hypertension (phenylephrine, PE), and concomitant hypoxemia and hypertension (N2 + PE). Arterial blood pressure was recorded by plethysmographic volume clamp, minute ventilation by pneumotachograph, and arterial O2 saturation by pulse oximeter. For all subjects, chronotropic baroresponse (Deltapulse interval/Deltasystolic blood pressure, where Delta is change) increased with NREM sleep (P = 0.007). Baroresponse slope was greater in Caucasians than in African-Americans (ANOVA, P = 0.02). Hypoxemic ventilatory response (Deltaminute ventilation/Deltaarterial O2 saturation) was greater in African-Americans than in Caucasians in NREM sleep (P = 0.01), as was hypoxemic attenuation of baroresponse (N2 + PE, P = 0.03). These data suggest sleep-related differences in arterial chemo- and baroreceptor responses in normal young African-Americans and Caucasians, which may have implications concerning development of systemic hypertension.

Clinical factors contributing to the differential diagnosis of primary insomnia and insomnia related to mental disorders.

OBJECTIVE: Primary insomnia and insomnia related to mental disorders are the two most common DSM-IV insomnia diagnoses, but distinguishing between them is difficult in clinical practice. This analysis was performed to identify clinical factors used by sleep specialists to distinguish primary insomnia from insomnia related to mental disorders. METHOD: Clinicians evaluated 216 patients referred for insomnia at five clinical sites, rated a list of clinical factors judged to contribute to each patient's presentation, and assigned diagnoses. Analysis of variance was performed, with contributing factors as the dependent variable and diagnostic group and clinic location as independent variables. RESULTS: Sleep specialists rated a psychiatric disorder as a stronger factor for insomnia related to mental disorders and rated negative conditioning and sleep hygiene as stronger factors for primary insomnia. However, a psychiatric disorder was rated as a contributing factor for 77% of patients who received a first diagnosis of primary insomnia. CONCLUSIONS: While neither sleep hygiene nor negative conditioning is a diagnostic criterion in DSM-IV, these results support the face validity of these clinical factors distinguishing between primary insomnia and insomnia related to mental disorders. The use of a psychiatric disorder as an inclusion criterion for insomnia related to mental disorders and an exclusion criterion for primary insomnia reinforces a categorical distinction between the two diagnoses, but the contribution of psychiatric symptoms in primary insomnia appears to be a clinically relevant one. These findings suggest the need for studies on the validity of negative conditioning and sleep hygiene in the etiology of primary insomnia, as well as on the significance of psychiatric disorders, especially depression, in primary insomnia.

Effect of induced transient arousal on obstructive apnea duration.

Six untreated male patients (age 19-55 yr) with obstructive sleep apnea underwent nocturnal polysomnography with acoustic stimulation to determine the effect of transient arousal on obstructive apneas during sleep. Binaural tone bursts (25-95 dB) were delivered in late expiration during the second obstructive apnea of a cycle consisting of four consecutive apneas. For the group, stimulated apneas were significantly shorter (P < 0.05, Fisher's protected least significant difference test) than were the unstimulated apneas when transient electrocortical arousal was elicited in both non-rapid-eye-movement (non-REM) sleep [mean 17 +/- 7 (SD) vs. 26 +/- 9, 23 +/- 10, and 26 +/- 12 s for 2nd vs. 1st, 3rd, and 4th apnea, respectively, of each cycle] and REM sleep (mean 19 +/- 10 vs. 35 +/- 15, 45 +/- 18, and 39 +/- 20 s). Without electrocortical arousal, the stimulated apnea was significantly shortened in non-REM (23 +/- 9 vs. 25 +/- 7, 24 +/- 8, and 26 +/- 8 s) but not in REM (32 +/- 16 vs. 37 +/- 12, 32 +/- 15, and 30 +/- 16 s). Tones delivered relatively early and late in the apnea were equally likely to be associated with resolution of the apnea. The nadir of arterial oxygen saturation of hemoglobin was inversely proportional to apnea length, with higher saturation nadirs associated with the stimulated apneas. These data indicate that transient arousal, induced by nonrespiratory stimulation, influences the resolution of obstructive apneas during sleep.

Diagnostic concordance for DSM-IV sleep disorders: a report from the APA/NIMH DSM-IV field trial.

OBJECTIVE: The frequency and ranking of DSM-IV sleep disorder diagnoses of clinical patients with complaints of insomnia, as well as rates of diagnostic agreement and disagreement between two types of interviewers, were investigated. METHOD: Interviewers at five clinical sites assessed 216 patients referred for insomnia complaints. One sleep specialist and one general clinician interviewed each patient in an unstructured clinical interview, assigned DSM-IV diagnoses, and indicated their reactions to the diagnostic system. RESULTS: Insomnia due to another mental disorder was the most frequent DSM-IV diagnosis across sites, followed by primary insomnia. Interviewers at the five sites differed significantly in the rankings they assigned to different diagnoses. In addition, sleep specialists at most sites diagnosed psychiatric forms of insomnia more frequently than nonspecialists. Kappa values for agreement between the two types of clinicians on multiple DSM-IV sleep diagnoses ranged from 0.26 to 0.80 across sites, indicating moderate agreement overall. Kappa values for individual diagnoses varied across sites and specific diagnoses and ranged from poor to excellent. Interviewers' ratings of their confidence in diagnoses and the fit and ease of use of the DSM-IV categories also showed significant variability related to site and type of interviewer. CONCLUSIONS: The distribution of diagnoses highlights the importance of psychiatric and behavioral factors in the assessment of insomnia. Site-related variability indicates a need for greater standardization in the application of sleep disorder diagnostic criteria. Diagnostic concordance for these diagnoses, while only moderately good, likely reflects actual clinical practice and would be improved through the use of standardized (or structured) interviews and increased training.

Hypnotics and behavior.

Evaluation of the effects of hypnotics on waking behavior has primarily focused on two issues: (1) how these drugs affect performance the day after a nightly dose; and (2) how they affect memory processes, with special emphasis on anterograde amnesia. In terms of the relations between pharmacologic properties and residual effects, three conclusions can be drawn. First, dose is a major determinant of the presence or absence of morning effects. Every drug studied to date, if given in high enough dose, has produced morning performance decrements. Second, the longer-acting a compound, the more likely it is that a performance decrement will be observed. Finally, some data suggest that behavioral tolerance to the residual effects of hypnotics develops. The observation that benzodiazepines produce amnesia emerged from reports of their clinical use as presurgery medications. Although the initial reports involved intravenous diazepam and were anecdotal in nature, subsequent studies have demonstrated that amnesia is a characteristic of all the benzodiazepines, with the magnitude of the effect being a function of route of administration, dose, and the pharmacokinetics of the particular drug.

Psychometric profiles of patient populations with excessive daytime sleepiness.

Patients with narcolepsy have more psychiatric symptoms than normal controls as measured by psychometric tests. However, it is unclear whether these findings are specific to narcolepsy, as some studies have suggested, or related to excessive daytime sleepiness (EDS) or to chronic illness. We compared a group of 56 narcoleptics to age- and sex-matched controls with EDS. A group of 48 individuals with normal sleep architecture was also used as an additional control group. Both the narcoleptic group and the EDS-control group had significantly greater scores on Minnesota Multiphasic Personality Inventory scales but were not different from each other. Our data suggest that the psychopathology associated with narcolepsy is not specific and may be generalized among patients with disorders of excessive sleepiness.

Evaluation and diagnosis of persistent insomnia.

The authors placed 84 patients who complained of insomnia into 10 diagnostic categories on the basis of medical, psychiatric, and polysomnographic evaluations. Only half the patients had objectively defined difficulty inducing or maintaining sleep when compared with 20 normal control subjects. However, all but 16 patients showed polysomnographic evidence of some sleep disorder. Diagnostic categories within the insomnia groups could be distinguished from one another by polysomnography. Patients in only 3 of the 10 diagnostic categories showed evidence of psychological distress on the MMPI; patients in the other 7 categories displayed few psychological symptoms. These results have implications for the treatment of insomnia.