Protocol to evaluate the impact of yoga supplementation on cognitive function in schizophrenia: a randomised controlled trial.

BACKGROUND: Schizophrenia (SZ) is a chronic illness that is treated symptomatically. Cognitive dysfunction is a core feature of SZ that is relatively intractable to pharmacotherapy. Yoga can improve cognitive function among healthy individuals. A recent open trial indicated significant benefits of yoga training (YT) in conjunction with conventional pharmacotherapy among patients with SZ. AIMS: To describe the protocol for an ongoing randomised controlled trial designed to test whether the reported beneficial effects of YT on cognitive function among SZ patients can be replicated. Secondarily, the effects of YT on daily functioning living skills are evaluated. METHODS: Consenting patients with SZ receive routine clinical treatment and are randomised to adjunctive YT, adjunctive physical exercise (PE) or treatment as usual (proposed N = 234 total, N = 78 in each group). The trial involves YT or PE 5 days a week and lasts 3 weeks. Participants are evaluated thrice over 6 months. Cognitive functions measured by Trail Making Test, University of Pennsylvania Neurocognitive Computerised Battery were primary outcome measures while clinical severity and daily functioning measured by Independent Living Skills Survey were secondary outcome measures. RESULTS: A total of 309 participants have been randomised as of 31 August 2013, which exceeded beyond 294 proposed after attrition. Once participants begin YT or PE they generally complete the protocol. No injuries have been reported. CONCLUSIONS: Short term YT is feasible and acceptable to Indian SZ patients. If beneficial effects of YT are detected, it will provide a novel adjunctive cognitive remediation strategy for SZ patients.

Exploring the associations of herpes simplex virus infection and cognitive dysfunction in schizophrenia: Studies in India.

BACKGROUND: Cognitive dysfunctions being core features of schizophrenia (SZ), cause disability, increase burden and are refractory to treatment. Viral infections are not risk factors for SZ, but growing evidence indicates infection with some neurotropic viruses, particularly Herpes simplex virus type 1 (HSV -1) as a risk factor for cognitive dysfunction. STUDIES IN INDIA: Three research studies in India are described. In the first, participants were evaluated for HSV-1 infection and cognitive functions (cases 198 and controls 100). In the second, patients and normal nonpsychotic control individuals were examined at baseline and followed up over 1-3 years (cases 138 and controls 88). In the third, a randomized, double-blind placebo-controlled antipsychotic adjunctive trial was conducted to examine the effect of anti-viral drug valacyclovir over 16 weeks on cognitive functioning (valacyclovir 30; placebo 32, treatment for 16 weeks). RESULTS OF INDIAN STUDIES: Cross-sectional study: HSV-1 infection was associated with modest dysfunction, especially on attention (accuracy) and spatial processing (speed). LONGITUDINAL STUDY: HSV-1 seropositive participants had lower scores at baseline on 6/16 measures, regardless of SZ diagnoses. At follow-up, there was a significant decline in HSV-1-positive participants for abstraction and mental flexibility and emotion discrimination. RANDOMIZED CONTROLLED TRIAL: Significantly, greater improvement in accuracy index of emotion discrimination in the valacyclovir-treated versus placebo sample was found. CONCLUSIONS: Indian studies are consistent with a causative role for HSV-1 in cognitive dysfunction regardless of SZ diagnosis; more rigorous studies of the causal hypothesis are needed, particularly larger randomized controlled trials.

Dopaminergic gene polymorphisms and cognitive function in a north Indian schizophrenia cohort.

BACKGROUND: Associations of polymorphisms from dopaminergic neurotransmitter pathway genes have mostly been reported in Caucasian ancestry schizophrenia (SZ) samples. As studies investigating single SNPs with SZ have been inconsistent, more detailed analyses utilizing multiple SNPs with the diagnostic phenotype as well as cognitive function may be more informative. Therefore, these analyses were conducted in a north Indian sample. METHODS: Indian SZ case-parent trios (n = 601 families); unscreened controls (n = 468) and an independent set of 118 trio families were analyzed. Representative SNPs in the Dopamine D3 receptor (DRD3), dopamine transporter (SLC6A3), vesicular monoamine transporter 2 (SLC18A2), catechol-o-methyltransferase (COMT) and dopamine beta-hydroxylase (DBH) were genotyped using SNaPshot/SNPlex assays (n = 59 SNPs). The Trail Making Test (TMT) was administered to a subset of the sample (n = 260 cases and n = 302 parents). RESULTS: Eight SNPs were nominally associated with SZ in either case-control or family based analyses (p < 0.05, rs7631540 and rs2046496 in DRD3; rs363399 and rs10082463 in SLC18A2; rs4680, rs4646315 and rs9332377 in COMT). rs6271 at DBH was associated in both analyses. Haplotypes of DRD3 SNPs incorporating rs7631540-rs2134655-rs3773678-rs324030-rs6280-rs905568 showed suggestive associations in both case-parent and trio samples. At SLC18A2, rs10082463 was nominally associated with psychomotor performance and rs363285 with executive functions using the TMT but did not withstand multiple corrections. CONCLUSIONS: Suggestive associations with dopaminergic genes were detected in this study, but convincing links between dopaminergic polymorphisms and SZ or cognitive function were not observed.