Psychological status and obstructive sleep apnea syndrome

Studies indicate a higher than average incidence of psychopathology in patients with obstructive sleep apnea syndrome (OSAS). However, problems arise when using instruments, such as the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), to determine the presence of psychopathology in this population, as these measures contain somatic items relating both to psychopathology and OSAS. Reporting these items can affect scores in such a way that a proportion of patients may appear to be experiencing psychopathology where none exists.;Records of patients admitted to the Sleep Disorders Center, Methodist Healthcare-University Hospital of Memphis were reviewed to determine eligibility for this study. A total of 400 patients with OSAS were included. All patients underwent polysomnography and completed the MMPI-2.;The primary hypotheses of this study included: "correcting" selected somatic items common to both psychopathology and OSAS on elevated MMPI-2 scales (primarily Depression, Hypochondriasis, and Hysteria) would lower scores; relationships would be found among psychological variables and sleep/apnea parameters; and more seriously affected patients would score higher on psychological measures.;Significant results from t-tests (all at p < .001) indicated that when MMPI-2 items were corrected, scale scores fell as follows: Hypochondriasis from 73.28 +/- 6.66 to 64.56 +/- 6.31; Depression from 71.28 +/- 5.27 to 66.26 +/- 4.98; Hysteria from 74.30 +/- 7.63 to 64.21 +/- 6.68. Regression analyses indicated that patients with a higher BMI, less Stage 2 sleep, and fewer non-REM related apnea events had higher Depression scores; individuals with a greater number of health problems had higher Hypochondriasis scores; and patients with a greater number of health problems and less stage 1 sleep had higher Hysteria scores. Our expected finding that individuals with more severe apnea would have a higher incidence of psychopathology was not statistically supported.;In conclusion, in our OSAS population, we found: that correcting somatic symptomatology common to both OSAS and psychopathology significantly lowered scale scores; severity of apnea had little association with elevated MMPI-2 scores; and there was a paucity of significant predictors between MMPI-2 and polysomnographic variables. This study points to the necessity of developing future research to clarify the association between OSAS and psychopathology.