Objective -To provide an update on recent research on depression and anxiety in obstructive sleep apnea syndrome (OSAS). Methods -A review was carried out on reports drawn from MEDLINE and PSYCHLIT (January 1995-June 2006 and identified from their list of references. The selection criteria were met by 55 articles. ResultsSample sizes in the reviewed studies varied widely and consisted mainly of working age men. Depression and anxiety were mostly evaluated with commonly used mood scales; only a few studies provided a psychiatric diagnosis. Prevalence figures fluctuated considerably for both depression (7-63%) and anxiety (11-70%). The effect of the continuous positive airway pressure (CPAP) on mood was inconsistent. Conclusions -Variations in the prevalence of depression and anxiety are affected by patient characteristics, mood assessment methods, and overlap between mood alterations and OSAS-related symptoms. CPAP might improve mood alterations but more long-term follow-up studies are needed to verify the effectiveness.

Objectives –  To provide an update on recent research concerning obstructive sleep apnea syndrome (OSAS) and executive functions. Methods –  A systematic review was carried out on reports drawn from MEDLINE and PSYCHLIT (January 1990–December 2005) and identified from lists of references in these reports. The selection criteria were met by 40 articles. Results –  The sample sizes in the reviewed studies varied widely and consisted mostly of selected groups. Most patient samples were heterogeneous in terms of the severity of OSAS. Executive functions were generally assessed with standardized test methods. Half of the studies assessed executive functions using only one or two tests. The most defected domains of executive functions were working memory, phonological fluency, cognitive flexibility, and planning. Continuous positive airway pressure (CPAP) treatment improved performance times, cognitive flexibility, and planning. Deficits in working memory and phonological fluency persisted. Conclusions –  Executive functions are the most defected cognitive domain in OSAS. Previous studies are affected by the heterogeneity of patient samples and the definitions of the domains of executive functions. Executive functions in OSAS should be assessed with a standardized neuropsychological test battery including assessments of different domains of executive functions. More research is needed on the efficiency of CPAP treatment on executive dysfunctions.

Aims: To clarify whether patients with obstructive sleep apnea syndrome (OSAS) have executive dysfunction, to identify the domains of executive function affected and to establish the severity of any dysfunction. Methods: A full-night polysomnography and a comprehensive neuropsychological assessment focusing on executive functions were conducted on 40 newly diagnosed OSAS patients and 20 healthy controls. The severity of dysfunction was analyzed using norm-referenced data. Results: All patients and controls were men. The groups did not differ statistically significantly in terms of age, education or intelligence quotient. Patients showed poorer performance than controls on the copy of the Rey-Osterrieth Complex Figure test, the Block Design, the Trails B of the Trail Making Test and the Intra-Extra Dimensional Set Shifting test. Based on the normative data, most OSAS patients performed at a normal level, but a few patients had either mild dysfunction (2.5–12.5%) or moderate to severe dysfunction (5–15%). Conclusions: OSAS patients have lower set-shifting and analysis/synthesis performance than healthy controls. According to the normative data, most patients in the present study had normal performance, but there were also a few patients with more serious deficits.

Aims: To assess the impact of continuous positive airway pressure (CPAP) treatment on executive dysfunction in patients with obstructive sleep apnea syndrome (OSAS). Methods: At baseline, 20 OSAS patients and 17 healthy controls underwent polysomnography and neuropsychological assessment focusing on executive functions. After at least 6 months of CPAP treatment, the patients returned for one more full-night polysomnography and neuropsychological control assessment, while the controls underwent a neuropsychological control assessment. Results: All patients and controls were working-age males. OSAS severity ranged from mild to severe. Before CPAP, patients showed poorer performance than controls in the copy of the Rey-Osterrieth Complex Figure Test, the Block Design, the Digit Symbol, the Trails B and the Intra-Extra Dimensional Set-Shifting task. Patients’ executive performance showed no improvement after CPAP, and it remained poorer than the performance of controls. In addition, patients showed no learning effect in the executive tests, whereas the controls did. Conclusion: Even long-term CPAP treatment does not seem to improve OSAS patients’ mental set-shifting performance or their visuospatial organizational skills. In addition, OSAS patients have impaired learning effect in executive tests.