Synchronous x-ray and radio mode switches: a rapid global transformation of the pulsar magnetosphere.

Pulsars emit from low-frequency radio waves up to high-energy gamma-rays, generated anywhere from the stellar surface out to the edge of the magnetosphere. Detecting correlated mode changes across the electromagnetic spectrum is therefore key to understanding the physical relationship among the emission sites. Through simultaneous observations, we detected synchronous switching in the radio and x-ray emission properties of PSR B0943+10. When the pulsar is in a sustained radio-"bright" mode, the x-rays show only an unpulsed, nonthermal component. Conversely, when the pulsar is in a radio-"quiet" mode, the x-ray luminosity more than doubles and a 100% pulsed thermal component is observed along with the nonthermal component. This indicates rapid, global changes to the conditions in the magnetosphere, which challenge all proposed pulsar emission theories.

Psychiatric comorbidity in Greek patients with generalized anxiety disorder.

From a total sample of 1,448 psychiatric outpatients, 81 (5.6%) received a diagnosis of generalized anxiety disorder (GAD) according to DSM-III-R criteria. Fifty-three (65%) of them had another Axis I diagnosis, while this percentage increased to 78% (63/81) when lifetime psychiatric diagnoses were recorded. The most frequent comorbid diagnoses were panic disorder, dysthymia, major depression and social phobia. Forty-three (53%) of the GAD patients met the criteria for personality disorder. They manifested obsessive-compulsive, avoidant personality and personalities of cluster C in general significantly more frequently than the rest of the total sample. The presence of a personality disorder was related to a significantly higher score on almost all the Minnesota Multiphasic Personality Inventory clinical and research scales, to a worse level of functioning and to an earlier age of onset of GAD. The results of the present study (1) support previous findings of high rates of comorbidity of clinical syndromes in GAD, (2) indicate that GAD co-occurs frequently with cluster C personality disorders, mainly avoidant and obsessive-compulsive, and (3) that the presence of a concomitant personality disorder is related to severer psychopathology and to a worse level of functioning.

Somatoform disorders: comorbidity with other DSM-III-R psychiatric diagnoses in Greece.

From a total sample of 1,448 psychiatric outpatients, 175 (12.1%) received a diagnosis of a somatoform disorder according to DSM-III-R criteria. One hundred twenty-two (70%) of these patients had another current axis I diagnosis, and this rate increased to 79% (139 of 175) when lifetime psychiatric diagnoses were recorded. The most frequent comorbid diagnoses were depressive disorders, i.e., dysthymia and major depression, and then anxiety disorders, mainly panic disorder. One hundred ten (63%) of the somatoform patients met the criteria for a personality disorder, significantly higher than the rate (52%) for the rest of the total sample (n = 1,273), who were used as a control group. The most frequent comorbid personality disorders were histrionic, dependent, and personalities of cluster B in general. Hypochondriasis was the only somatoform disorder that was additionally significantly related to obsessive-compulsive personality disorder. Somatoform patients with a concomitant personality disorder manifested more severe overall psychopathology as measured by the Minnesota Multiphasic Personality Inventory (MMPI) and a worse level of functioning than those without. The results of the present study show that (1) patients with somatoform disorders have a high rate of comorbidity with other clinical syndromes and personality disorders, and (2) the presence of a personality disorder is related to more severe overall psychopathology and a worse level of functioning. All of the above indicate that special attention must be paid to the interaction between somatoform disorders, other clinical syndromes, and personality structure at the level of both clinical and research practice.

Personality disorders in dysthymia and major depression.

OBJECTIVE: The purpose of the present study was to investigate the comorbidity of personality disorders in patients with primary dysthymia compared to those with episodic major depression. METHOD: A total of 177 out-patients with primary dysthymia and 187 outpatients with episodic major depression were administered a structured diagnostic interview for DSM-III-R Axis II disorders. In addition, all of these patients completed the BDI, and those with the appropriate level of education also completed the Minnesota Multiphasic Personality Inventory (MMPI). RESULTS: A significantly higher proportion of dysthymic patients than patients with major depression met the criteria for a personality disorder, for borderline, histrionic, avoidant, dependent, self-defeating types and for personality disorders of clusters B and C. Further analysis revealed that the above differences were mainly due to the subgroup of patients with 'early-onset dysthymia'. Finally, patients with a personality disorder, both dysthymics and those with major depression, had significantly higher scores on the BDI and on the majority of the MMPI scales compared to those without a personality disorder. CONCLUSION: The data indicated that (i) dysthymia--mainly that of early onset--is associated with significantly higher personality disorder comorbidity than episodic major depression, and (ii) the presence of a personality disorder is related to more severe overall psychopathology.

Greek version of the General Health Questionnaire: accuracy of translation and validity.

The purpose of this study was to examine the accuracy of translation and to test the validity of the Greek version of the General Health Questionnaire (GHQ). In the translation study, the English and the Greek versions of the GHQ were administered to a sample of 50 bilingual respondents. The internal consistency, item-by-item and the subject-by-subject analysis have shown that the 2 versions are equivalent and therefore the Greek translation is highly accurate. In the validity study, 100 consecutive patients attending an internal medicine outpatient clinic completed the Greek version of the GHQ-60 and were interviewed independently using the Present State Examination (PSE). The validity of the shorter forms of the questionnaire (GHQ-30 and GHQ-28) was tested by disembedding the relevant items from the larger set. The correlations obtained between the scores of the questionnaire and the PSE ratings, as well as all the validity indices (sensitivity, specificity, positive predictive value, negative predictive value and overall misclassification rate) were quite satisfactory for all the GHQ forms, thus confirming the validity of the questionnaire in its Greek version. The best cut-off points as found by receiver-operating characteristics analysis were 11/12 for the GHQ-60, 5/6 for the GHQ-30 and 4/5 for the GHQ-28. The revised (CGHQ) scoring system for the GHQ-30 has not been proved superior to the conventional scoring method. The above results are discussed in relation to the pertinent literature and especially the studies carried out in similar settings and in countries with similar cultural backgrounds.