Higher methadone doses are associated with lower mortality in patients of opioid dependence in Taiwan.

Optimal methadone dosage and service profile is challenging in treatment of opioid dependence. This study explores the impact of methadone dosage on the mortality of opioid-dependent patients in methadone maintenance therapy by using a large-scale and continual supervised dosing registry information system. Database of nationwide enrolled opioid-dependent patients at methadone clinics in Taiwan during 2006-2008 was assessed. The relative risk of age, sex, marital status, HIV infection and methadone dosage were analyzed by Cox regression analysis. Among all of the 33,549 recruited patients, the crude mortality rate was 134.78/10,000 person-years, and the standardized mortality ratio was 4.68. A dose-response relationship of higher- vs. lower-dosage groups on the risk of mortality risk was observed (adjusted HR = 0.68, P = 0.016). In further sub-grouping analysis, this trend was more significant in HIV positive patients, in subgroup of patients who continuously staying in MMT, and in subgroup of patients who re-enter MMT. This dosage effect is not significantly seen in patients receiving MMT more than 365 days. Further exploration of other treatment-related factors may be important for understanding the long-term treatment outcome of opioid addiction patients.

Symptom patterns and subgrouping of schizophrenic patients: significance of negative symptoms assessed on admission.

This study subgroups schizophrenic patients based on symptoms assessed on admission and examines the validity of the subgrouping using follow-up data and other clinical outcome variables. Schizophrenic patients (n=163) from consecutive admission received ratings on the positive and negative syndrome scale (PANSS) on admission and during a 1-year follow-up course. An exploratory graphic analysis on the admission PANSS derived four symptom dimensions: negative symptoms, disorganized thought, hostility/excitement and delusions/hallucinations. This yielded two subgroups of patients on admission, a group with marked negative (GWNEG) and a group without marked negative (GONEG) symptoms. Compared with the GONEG, the GWNEG had a poorer recovery rate, more impairment in attention, a slower response of the delusion/hallucination symptoms to neuroleptic treatment and a longer duration of index hospitalization. At a one-year follow-up, the GWNEG assessed on admission had persistently higher scores on the negative symptom and disorganized thought syndromes, less relapse rate, a shorter duration on job, as well as worse social functioning than the GONEG. Thus, the GONEG might comprise patients having a pure paranoid syndrome with quick and better treatment response, while the GWNEG comprises patients with the blunt-disorganization syndrome having a poorer outcome.

Morbidity risk of psychiatric disorders among the first degree relatives of schizophrenia patients in Taiwan.

This study aimed to assess the boundaries of the schizophrenia spectrum and whether inclusion of such phenotypes increases power for linkage analysis of schizophrenia. Participants were 234 first degree relatives (FDRs) of 94 schizophrenia probands in Northern Taiwan who completed a direct interview using the Diagnostic Interview for Genetic Studies (DIGS). Based on best estimate diagnosis, the morbidity risk in the relatives for schizophrenia was 2.5 percent (Weinberg's shorter method) or 3.9 percent (Kaplan-Meier estimate). Depending on the stringency of diagnosis, lifetime prevalence was 2.6 percent to 4.7 percent for schizotypal personality disorder, 3.4 percent to 8.6 percent for paranoid personality disorder, and 1.3 percent to 3.4 percent for schizoid personality disorder. These figures are significantly higher than the corresponding figures in the general population. However, none of the recurrence risk ratio for any spectrum that included both schizophrenia and a personality disorder (3.0 to 5.9) was greater than that of schizophrenia alone (9.3 to 14.4). Thus, including schizophrenia-related personality disorders in the spectrum did not increase power for linkage analysis of schizophrenia.