1.
Superoxide Dismutase, BDNF, and Cognitive Improvement in Drug-Naive First-Episode Patients With Schizophrenia: A 12-Week Longitudinal Study.
Wu, Z, Liu, Q, Zhang, Y, Guan, X, Xiu, M, Zhang, X
The international journal of neuropsychopharmacology. 2022;(2):128-135
Abstract
OBJECTIVE Cognitive improvement after antipsychotic agents in patients with schizophrenia (SCZ) appears to involve redox regulation through neurotrophins such as brain derived neurotropic factor (BDNF). This study examined whether cognitive improvement was associated with the increase in superoxide dismutase (SOD) and whether higher levels of BDNF could have a permissive role in allowing SOD to improve cognition. METHODS We examined this hypothesis in 183 drug-naïve first-episode SCZ patients taking risperidone monotherapy for 12 weeks. We measured total copper-zinc SOD (CuZn-SOD), manganese SOD (Mn-SOD), and SOD activities and BDNF levels in these patients and compared their levels with 152 healthy controls. We assessed cognitive functioning and clinical symptoms at baseline and 12-week follow-up. RESULTS After treatment with risperidone, CuZn-SOD activity was significantly increased, and BDNF levels were slightly increased. Increased CuZn-SOD activity was associated with the cognitive effectiveness of risperidone monotherapy. The BDNF levels and SOD activities were correlated at baseline but not after 12-week treatment. Furthermore, baseline CuZn-SOD activity positively correlated with improvement on the delayed memory subscale of the Repeatable Battery for the Assessment of Neuropsychological Status only in the high BDNF subgroup. CONCLUSIONS Our longitudinal study suggests that risperidone can enhance SOD activity and that, in combination with higher baseline BDNF levels acting in a permissive role, can improve cognitive impairments in SCZ. Greater baseline CuZn-SOD activity also may have predictive value for cognitive improvement of delayed memory in SCZ patients receiving risperidone treatment.
2.
Effects of quetiapine on cognitive functions in schizophrenic patients: a preliminary single-trial ERP analysis.
Zhang, Y, Lehmann, M, Shobeiry, A, Höfer, D, Johannes, S, Emrich, HM, Dietrich, DE
Pharmacopsychiatry. 2009;(4):129-34
Abstract
AIM: The study aimed to explore by means of single-trial event-related potentials (ERPs), whether and how the medication change from older neuroleptics to quetiapine in schizophrenic patients led to a significant cognitive enhancement. This single-trial ERP analysis helps to investigate attention and memory processes in the single patient before and after treatment. PATIENTS AND METHODS Thirteen schizophrenic patients (mean age: 40.1+/-13.5 years) were followed up for 16 weeks and assessed for changes of clinical symptoms and ERP components P300 representing target detection processes and N400 indexing context integration in word recognition processes. Three subjects had to be excluded from the ERP recording sessions because of excessive blink artefacts and movements. RESULTS Regarding the P300 components of the target detection, there were significant increases of amplitudes in 5 of 10 patients (50%) at week 16 comparing with week 0. Regarding the N400 components of the word recognition, there were significant increases of amplitudes in 4 of 10 patients (40%) at week 16 comparing with week 0. DISCUSSION The mean scores of PANSS, MADRS, Bf-S, SCL-90 and CGI-S at the end of study (week 16) showed significant improvements compared to the baselines (week 0) (p<0.05). During the study, no extrapyramidal symptoms as well as akathisia were reported after quetiapine treatment. These preliminary data suggest that quetiapine might partially improve the cognitive functions in the context integration and target detection processing in these patients. This technical procedure (single-trial ERP) may help to differentially assess cognitive enhancements in each single patient under treatment.