Fritz Hohagen

Test–retest reliability and validity of the Pittsburgh Sleep Quality Index in primary insomnia

OBJECTIVE Psychometric evaluation of the Pittsburgh Sleep Quality Index (PSQI) for primary insomnia. METHODS The study sample consisted of 80 patients with primary insomnia (DSM-IV). The length of the test-retest interval was either 2 days or several weeks. Validity analyses were calculated for PSQI data and data from sleep diaries, as well as polysomnography. To evaluate the specificity of the PSQI, insomnia patients were compared with a control group of 45 healthy subjects. RESULTS In primary insomnia patients, the overall PSQI global score correlation coefficient for test-retest reliability was .87. Validity analyses showed high correlations between PSQI and sleep log data and lower correlations with polysomnography data. A PSQI global score > 5 resulted in a sensitivity of 98.7 and specificity of 84.4 as a marker for sleep disturbances in insomnia patients versus controls. CONCLUSION The PSQI has a high test-retest reliability and a good validity for patients with primary insomnia.

Neuropsychological performance in obsessive-compulsive disorder: a critical review

There is growing evidence for neuropsychological dysfunction in obsessive-compulsive disorder (OCD) related to an underlying frontal lobe and/or basal ganglia dysfunction. The following paper is a systematical review of the existing literature on cognitive impairment in OCD patients. Fifty studies were surveyed with regard to methodological aspects and cognitive impairments found in OCD patients. In addition, the impact of confounding variables such as psychotropic medication, co-morbidity or severity of symptoms on neuropsychological functioning as well as effects of treatment are discussed. OCD is often related to memory dysfunction that seems to be associated with impaired organization of information at the stage of encoding. Several other executive functions are also commonly disturbed, though results are inconsistent. The results of our study suggest that some cognitive deficits seem to be common in OCD, but future studies should focus more on possible confounding variables such as co-morbidity or psychotropic medication.

Prevalence and treatment of insomnia in general practice. A longitudinal study

SummaryThe aim of the study was to assess prevalence and treatment modalities of insomnia in general practice. To investigate the course of insomnia, a longitudinal study design was adopted. Two thousand five hundred and twelve patients (age 18–65 years) were investigated with a questionnaire in general practice (T1). Four months later (T2) and again 2 years later (T3) a questionnaire was sent to all patients who had complained about severe insomnia at the time of the first inquiry. To assess insomnia, operationalized diagnostic criteria were applied (DSM-III-R). Eighteen point seven percent suffered from severe, 12.2% suffered from moderate and 15% suffered from mild insomnia. In the course of 2 years insomnia appeared as a chronic health problem. A high comorbidity of severe insomnia was found with chronic somatic and psychiatric disorders, especially with depression. Of the severely insomniac patients, 23.9% used prescribed hypnotics habitually, mainly benzodiazepines. The use of prescribed hypnotics remained rather stable during the whole study period. More than half of the patients reported a daily use of the hypnotics for 1–5 years or longer, but only 22% of the severely insomniac patients reported at the time of the third inquiry a significant improvement of insomnia due to the administration of sleeping pills. Thus, the long-term administration of benzodiazepine hypnotics seems to be an inadequate treatment strategy in chronic insomnia. Whether the occurrence of rebound insomnia after benzodiazepine withdrawal may be one of the main factors for chronic hypnotic use requires discussion. Although insomnia may be an important symptom of many somatic and psychiatric disorders, the general practitioner was unaware in more than half of the cases that the patients suffered from a sleep problem. Severe insomniac patients displayed a higher mean number of medical consultations compared with good sleepers or patients with mild insomnia, indicating that insomnia constitutes a significant burden for the primary care physicians.

Sleep disturbances are correlated with decreased morning awakening salivary cortisol

Morning and evening salivary cortisol levels were correlated with sleep parameters in 14 patients with primary insomnia and 15 healthy controls. Salivary cortisol was sampled immediately after awakening (T1), 15 min later (T2), and immediately before going to bed (T3) for 1 week at home. In parallel with this, subjects estimated parameters of sleep in a daily sleep log. Patients and controls were all non-smokers who did not differ regarding morning awakening time or bedtime. Cortisol after awakening was significantly decreased in primary insomnia. Salivary cortisol at the time of awakening correlated negatively with the subjective estimation of sleep quality, i.e. a low salivary cortisol level directly after awakening correlated with a higher frequency of nightly awakenings (r = -0.50), a diminished sleep quality (r = -0.34) and a decreased feeling of recovery after awakening (r = -0.35; all p < 0.05). Furthermore, awakening cortisol was negatively correlated with the Pittsburgh Sleep Quality Index (r = -0.43) and with a questionnaire on sleep-related cognitions with the subscales rumination in bed (r = -0.56 ) and focusing on sleep-related thoughts (r = -0.46; all p < 0.05).

Impaired declarative memory consolidation during sleep in patients with primary insomnia: Influence of sleep architecture and nocturnal cortisol release.

BACKGROUND A central cognitive function of sleep is to consolidate newly acquired memories for long-term storage. Here, we investigated whether the overnight consolidation of declarative memory in patients with chronic sleep disturbances is impaired, owing to less slow wave sleep (SWS) and an increased cortisol release. METHODS Polysomnographic recordings, serum cortisol concentrations, and overnight memory consolidation in 16 patients with primary insomnia were compared with those of 13 healthy control subjects. RESULTS Patients displayed distinctly less overnight consolidation of declarative memory (p < .05), which was significantly correlated with SWS in the control subjects (r = .69) but with rapid eye movement (REM) sleep in the patients (r = .56), who had a diminished amount of SWS (p < .05). Increased cortisol levels in the middle of the night were associated with impaired retrieval of declarative memory after sleep for both control subjects (r = -.52) and patients (r = -.46). CONCLUSIONS Primary insomnia is associated with a diminished sleep-related consolidation of declarative memory. Efficient overnight consolidation of declarative memory is associated with high amounts of SWS and low serum cortisol levels during the early part of the night. Where SWS is decreased, REM sleep might play a partly compensatory role in the consolidation of declarative memory.

Cognitive frontal lobe dysfunction in obsessive-compulsive disorder.

BACKGROUND There is evidence that dysfunction within associative frontostriatal circuits represents a feature of obsessive-compulsive disorder (OCD). Previous neuropsychologic studies have yielded diverging results, which may in part be explained by differences in the selection of subjects and methods. The present study focused on the question of cognitive frontal lobe performance in OCD. METHODS Twenty-nine unmedicated OCD patients were compared to a double-size control group of normal subjects matched individually for age, sex, and intelligence. A series of 12 neuropsychologic tests was applied, most of which are thought to be sensitive to different aspects of cognitive frontal lobe function. RESULTS OCD patients were unimpaired at tests of abstraction, problem solving, set-shifting, response inhibition, active memory search, and choice reaction speed. Deficits of approximately one standard deviation were observed at timed tests of verbal and nonverbal fluency, attentional processing, and weight sorting. CONCLUSIONS OCD patients exhibited selective deficits in tasks involving controlled attentional processing and self-guided, spontaneous behavior. We discuss a link between this neuropsychologic profile and dysfunctioning within the anterior cingulate, but not the dorsolateral prefrontal circuit.

1H-magnetic resonance spectroscopy in obsessive-compulsive disorder: evidence for neuronal loss in the cingulate gyrus and the right striatum.

We compared 12 patients with obsessive-compulsive disorder (OCD) and six control subjects by 1H-magnetic resonance spectroscopy. Significantly lower relative N-acetyl-aspartate (NAA) levels were found in the right striatum of OCD patients, as well as a decrease of anterior cingulate NAA that correlated with severity of illness. Age and sex were correlated to striatal NAA levels.

Prevalence of insomnia in elderly general practice attenders and the current treatment modalities

This study aimed to assess the prevalence and treatment modalities of elderly practice attenders. A total of 330 patients aged over 65 years were investigated with a questionnaire in general practice. To assess insomnia, operationalized diagnostic criteria according to DSM‐III‐R were applied. Twenty‐three percent of the elderly patients suffered from severe, 17% from moderate and 17% from mild insomnia. More than 80% of the patients reported suffering from insomnia for 1–5 years or longer, which indicates a chronic course. Elderly patients showed unrealistic expectations concerning duration of sleep and spend more time in bed than they realistically can expect to sleep. More than half of the elderly patients reported habitual daytime napping. Sleep‐disturbed elderly patients did not differ significantly from good sleepers in their habit of taking daytime naps, but even when taking daytime naps, good sleepers slept significantly longer than the sleep‐disturbed patients. A significant association was found between insomnia and mental disorders, i.e., depression and organic brain syndrome according to the diagnosis of the general physician. In about half of the cases the primary care physician was not aware that the elderly patient suffered from severe insomnia. More than half of the elderly severe insomniacs took prescribed hypnotics habitually, mainly benzodiazepines.

Immediate as well as delayed post learning sleep but not wakefulness enhances declarative memory consolidation in children

While there is mounting evidence for the importance of sleep for declarative memory consolidation in adults, so far this issue has not been investigated in children despite considerable differences in sleep duration and sleep architecture between children and adults. Here, 27 children (aged between 9 and 12yr) were examined on two conditions: on the Sleep-Wake condition, subjects learned word pairs in the evening and delayed recall was tested first in the next morning after sleep and then again in the following evening after daytime wakefulness. On the Wake-Sleep condition, learning took place in the morning and delayed recall was tested in the evening of the same day and again in the next morning after sleep. In both conditions retention of declarative memory was significantly increased only after an interval of sleep that either followed immediately after learning (as in the Sleep-Wake condition) or that followed after daytime wakefulness (as in the Wake-Sleep condition), respectively. The results support the hypothesis that sleep plays an active role in declarative memory consolidation even if delayed and further show for the first time the importance of sleep for declarative memory consolidation during childhood.

Long-term effectiveness of a short-term cognitive-behavioral group treatment for primary insomnia.

Abstract The long-term effectiveness of a short-term cognitive-behavioral therapy was evaluated. The structured group treatment consisted of six weekly sessions and included progressive muscle relaxation, cognitive relaxation, modified stimulus control with bedtime restriction, thought stopping and cognitive restructuring. Twenty patients with chronic primary insomnia took part in the study. All patients were referred by physicians for diagnosis and therapy of insomnia. During a waiting period of six weeks prior to treatment, patients did not experience any change of their sleep parameters. After therapy, patients improved their total sleep time and sleep efficiency and reduced their sleep latency and negative sleep-related cognitions. Furthermore, depression scores decreased. Most of the treatment effects were significant at the end of the treatment and remained stable over the long-term follow-up, which was evaluated after a mean of almost three years (35±6.7 months). The subjective estimated total sleep time improved from 298±109 min prior to therapy to 351±54 min at the end of treatment, to 376±75 min at the 3-month follow-up, to 379±58 min at the 12-month follow-up and to 381±92 min. at the long-term follow-up.