Long-term cognitive trajectories and heterogeneity in patients with schizophrenia and their unaffected siblings.

OBJECTIVE: This study aimed to assess the heterogeneity and stability of cognition in patients with a non-affective psychotic disorder and their unaffected siblings. In addition, we aimed to predict the cognitive subtypes of siblings by their probands. METHOD: Assessments were conducted at baseline, 3 and 6 years in 1119 patients, 1059 siblings and 586 controls from the Genetic Risk and Outcome of Psychosis (GROUP) study. Group-based trajectory modeling was applied to identify trajectories and clustered multinomial logistic regression analysis was used for prediction modeling. A composite score of eight neurocognitive tests was used to measure cognitive performance. RESULTS: Five stable cognitive trajectories ranging from severely altered to high cognitive performance were identified in patients. Likewise, four stable trajectories ranging from moderately altered to high performance were found in siblings. Siblings had a higher risk of cognitive alteration when patients' alteration was mild (OR = 2.21), moderate (OR = 5.70), and severe (OR = 10.07) compared with patients with intact cognitive function. The familial correlation coefficient between pairs of index patients and their siblings was 0.27 (P = 0.003). CONCLUSIONS: The cognitive profiles identified in the current study might be suitable as endophenotypes and could be used in future genetic studies and predicting functional and clinical outcomes.

Efficacy of bilateral repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia: results of a multicenter double-blind randomized controlled trial.

BACKGROUND: Few studies have investigated the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment for negative symptoms of schizophrenia, reporting inconsistent results. We aimed to investigate whether 10 Hz stimulation of the bilateral dorsolateral prefrontal cortex during 3 weeks enhances treatment effects. METHOD: A multicenter double-blind randomized controlled trial was performed in 32 patients with schizophrenia or schizo-affective disorder, and moderate to severe negative symptoms [Positive and Negative Syndrome Scale (PANSS) negative subscale ⩾15]. Patients were randomized to a 3-week course of active or sham rTMS. Primary outcome was severity of negative symptoms as measured with the Scale for the Assessment of Negative Symptoms (SANS) and the PANSS negative symptom score. Secondary outcome measures included cognition, insight, quality of life and mood. Subjects were followed up at 4 weeks and at 3 months. For analysis of the data a mixed-effects linear model was used. RESULTS: A significant improvement of the SANS in the active group compared with sham up to 3 months follow-up (p = 0.03) was found. The PANSS negative symptom scores did not show a significant change (p = 0.19). Of the cognitive tests, only one showed a significant improvement after rTMS as compared with sham. Finally, a significant change of insight was found with better scores in the treatment group. CONCLUSIONS: Bilateral 10 Hz prefrontal rTMS reduced negative symptoms, as measured with the SANS. More studies are needed to investigate optimal parameters for rTMS, the cognitive effects and the neural basis.

Applying the Quebec Task Force criteria as a frame of reference for studies of whiplash injuries.

Research prior to 1995 showed a diversity of either inclusion or exclusion criteria (or both) for diagnosing whiplash injury. As a consequence, the Quebec Task Force (QTF) developed expert-based criteria, which may be considered as a the 'new' gold standard. Here, we examined the inclusion criteria and exclusion criteria used in research populations from the major 82 research studies performed during the period 1980-1998, comparing their similarities and dissimilarities to the QTF standard. None of the articles satisfied the QTF definitions completely, either before or after their introduction in 1995. Nevertheless, the QTF still seems to have had some impact on either the published inclusion or exclusion criteria. We observed that both sets of criteria showed a qualitative shift following the QTF publication in 1995. For the inclusion criteria, we found both a statistically significant increase in use of the QTF definition (acceleration-deceleration mechanism, rear-end collision, motor vehicle collision or other mishaps) and in the criterion 'neck pain'. We also observed some smaller changes in both inclusion and exclusion criteria but none of these was significant statistically.