Is there an Association between Metabolic Disorder & Cognitive Impairment in Patients with Early-Stage Schizophrenia?

Research Paper Title

The Association Between Metabolic Disturbance and Cognitive Impairments in Early-Stage Schizophrenia.

Background

Cognitive impairment is one of the core symptoms of schizophrenia, which is considered to be significantly correlated to prognosis. In recent years, many studies have suggested that metabolic disorders could be related to a higher risk of cognitive defects in a general setting. However, there has been limited evidence on the association between metabolism and cognitive function in patients with early-stage schizophrenia.

Methods

In this study, the researchers recruited 172 patients with early-stage schizophrenia. Relevant metabolic parameters were examined and cognitive function was evaluated by using the MATRICS Consensus Cognitive Battery (MCCB) to investigate the relationship between metabolic disorder and cognitive impairment.

Results

Generally, the prevalence of cognitive impairment among patients in our study was 84.7% (144/170), which was much higher than that in the general population. Compared with the general Chinese setting, the study population presented a higher proportion of metabolic disturbance. Patients who had metabolic disturbance showed no significant differences on cognitive function compared with the other patients. Correlation analysis showed that metabolic status was significantly correlated with cognitive function as assessed by the cognitive domain scores (p < 0.05), while such association was not found in further multiple regression analysis.

Conclusions

Therefore, there may be no association between metabolic disorder and cognitive impairment in patients with early-stage schizophrenia.

Reference

Peng, X-J., Hei, G-R., Li, R-R., Yang, Y., Liu, C-C., Xiao, J-M., Long, Y-J., Shao, P., Huang, J., Zhao, J-P. & Wu, R-R. (2021) The Association Between Metabolic Disturbance and Cognitive Impairments in Early-Stage Schizophrenia. Frontiers in Human Neuroscience. doi: 10.3389/fnhum.2020.599720. eCollection 2020.

Major Depressive Disorder: Childhood Trauma

Research Paper Title

Major depressive disorder with childhood trauma: Clinical characteristics, biological mechanism, and therapeutic implications.

Background

Major depressive disorder (MDD) is a main type of mood disorder, characterised by significant and lasting depressed mood.

Until now, the pathogenesis of MDD is not clear, but it is certain that biological, psychological, and social factors are involved.

Childhood trauma is considered to be an important factor in the development of this disease.

Previous studies have found that nearly half of the patients with MDD have experienced childhood trauma, and different types of childhood trauma, gender, and age show different effects on this disease.

In addition, the clinical characteristics of MDD patients with childhood trauma are also different, which often have more severe depressive symptoms, higher risk of suicide, and more severe cognitive impairment.

The response to antidepressants is also worse.

In terms of biological mechanisms and marker characteristics, the serotonin transporter gene and the FKBP prolyl isomerase 5 have been shown to play an important role in MDD and childhood trauma.

Moreover, some brain imaging and biomarkers showed specific features, such as changes in gray matter in the dorsal lateral prefrontal cortex, and abnormal changes in hypothalamic-pituitary-adrenal axis function.

Reference

Guo, W., Liu, J. & Li, L. (2020) Major depressive disorder with childhood trauma:Clinical characteristics, biological mechanism, and therapeutic implications. Zhong nan da xue xue bao. Journal of Central South University. 45(4), pp.462-468. doi: 10.11817/j.issn.1672-7347.2020.190699.

Is Varenicline a Useful Target Compound for Improving Cognitive Impairment in Schizophrenia?

Research Paper Title

Varenicline for cognitive impairment in people with schizophrenia: systematic review and meta-analysis.

Background

People with schizophrenia frequently have cognitive dysfunction, which does not respond to pharmacological interventions. Varenicline has been identified as a potential treatment option for nicotinic receptor dysfunction with a potential to treat cognitive impairment in schizophrenia.

Methods

The researchers conducted a systematic review of Pubmed, Embase, Psycinfo, CINAHL and the Cochrane Schizophrenia Trial Registry for randomised controlled trials of varenicline in people with schizophrenia for cognitive dysfunction.

They excluded trials among people with dementia. They then undertook a meta-analysis with the primary outcome of difference in change of cognitive measures between varenicline and placebo as well as secondary outcomes of difference in rates of adverse events.

They also conducted a sensitivity analysis on smoking status and study duration.

Results

The researchers included four papers in the meta-analysis (n = 339).

Varenicline was not superior to placebo for:

  • Overall cognition (SMD = -0.022, 95% CI -0.154-0.110; Z = -0.333; p = 0.739);
  • Attention (SMD = -0.047, 95% CI -0.199-0.104; Z = -0.613; p = 0.540);
  • Executive function (SMD = -0.060, 95% CI -0.469-0.348; Z =- 0.290; p = 0.772); or
  • Processing speed (SMD = 0.038, 95% CI -0.232-0.308; Z = 0.279; p = 0.780).

There was no difference in psychotic symptoms, but varenicline was associated with higher rates of nausea.

Sensitivity analyses for smoking status and study duration did not alter the results.

Conclusions

Within the present literature, varenicline does not appear to be a useful target compound for improving cognitive impairment in schizophrenia.

Based on these results, a trial would need over 2,500 participants to be powered to show statistically significant findings.

Reference

Tanzer, T., Shah, S., Benson, C., De Monte, V., Gore-Jones, V., Rossell, S.L., Dark, F., Kisely, S., Siskind, D. & Melo, C.D. (2019) Varenicline for cognitive impairment in people with schizophrenia: systematic review and meta-analysis. Psychopharmacology. doi: 10.1007/s00213-019-05396-9. [Epub ahead of print].