14 March 2019
Could improving cognitive dysfunction in major depression also improve mood?
We caught up with Mohammad Ali Salehinejad to discuss the results of his latest publication entitled: Cognitive control dysfunction in emotion dysregulation and psychopathology of major depression (MD): Evidence from transcranial brain stimulation of the dorsolateral prefrontal cortex (DLPFC).
Can you tell us more about your research group?
I am a student at the International Graduate School of Neuroscience (IGSN)-Ruhr University Bochum, as well as a research fellow in the Department of Psychology & Neurosciences at ifADo, under the supervision of Prof. Michael Nitsche.
Our research group uses non-invasive brain stimulation techniques (i.e., tDCS, TMS), imaging methods (i.e., EEG, TMS-EEG, fMRI), and pharmacological interventions to study the physiological basis, underlying cognitive mechanisms and behavioral consequences of brain plasticity and neuromodulation, in both healthy and neuropsychiatric populations. My specific interests are:
(1) executive functions underpinned by the prefrontal cortex for healthy individuals, and some clinical populations with frontal abnormalities
(2) modulating neuroplasticity, and
(3) enhancing cognitive function using the above-mentioned techniques.
What is the rationale behind your study?
Cognitive theories of depression have suggested that cognitive impairments may play an important role in depression psychopathology. However, there have been limited studies at a neurocognitive level.
Interestingly, MD is marked by significant executive dysfunctions, such as biased attention. Moreover, executive dysfunctions are frequently associated with abnormalities in prefrontal cortex.
Our study aimed to investigate whether these executive dysfunctions could be affected by modulating activity in the prefrontal cortex with noninvasive brain stimulation (i.e., tDCS). If so, we might expect not only cognitive improvements but also improvements in mood.
Which methods did you use?
I used transcranial direct current stimulation (tDCS), which is a noninvasive brain stimulation technique. tDCS uses a weak direct current stimulation for modulating brain excitability and plasticity. The major strength of using tDCS is the ability to directly monitor the impact of modulating cortical activity on cognitive function.
What are your key findings?
We found that the modulation of activity in the prefrontal cortex (PFC) could improve performance on the executive function tasks. But interestingly we also observed significant improvements in the mood of depressed individuals.
What are the implications of your study?
The major implications of our findings are that: 1) by improving executive dysfunctions in MD, we may expect to see positive effects on mood too, and 2) cognitive dysfunction in depression may play a greater role in MD psychopathology. Of the latter implications need to be examined in future studies.
Why did you choose CANTAB?
I used CANTAB because, first of all, it is a comprehensive neuropsychological battery with various tests for measuring executive functions. Secondly, it offers specific batteries for different disorders affected by cognitive dysfunction. Thirdly, previous studies have shown that CANTAB sensitive to frontal lobe abnormalities, which is important for MD research. Lastly, CANTAB is feasible and easy to use, especially with the screen touch compatible options.
Interested in discovering the latest research articles in your field?
Mohammad Ali Salehinejad, PhD student at the International Graduate School of Neuroscience (IGSN)-Ruhr University Bochum and research fellow in the Department of Psychology & Neurosciences at ifADo.