Objectives: The objective of this post hoc exploratory analysis was to examine the relationship between age and measures of cortical excitability and inhibition. Methods: Forty-six participants (24 with major depressive disorder and 22 healthy controls) completed MT, SICI, ICF, and CSP testing in a cross-sectional protocol. Of these 46 participants, 33 completed LICI testing. Multiple linear robust regression and Spearman partial correlation coefficient were used to examine the relationship between age and the TMS measures. Results: In the overall sample of (...) 46 participants, age had a significant negative relationship with motor threshold in both the right (rs = -0.49, adjusted p =.007; β= -0.08, adjusted p=.001) and left (rs = -0.42, adjusted p =.029; β= -0.05, adjusted p=.004) hemispheres. This significant negative relationship of age with motor threshold was also observed in the sample of depressed youth in both the right (rs = -0.70, adjusted p =.002; β= -0.09, adjusted p=.001) and left (rs = -0.54, adjusted p =.034; β= -0.05, adjusted p=.017) hemispheres, but not in healthy controls. In the sample of the 33 participants who completed LICI testing, age had a significant negative relationship with LICI (200 millisecond interval) in both the right (rs = -0.48, adjusted p =.05; β= -0.24, adjusted p=.007) and left (rs = -0.64, adjusted p =.002; β= -0.23, adjusted p=.001) hemispheres. This negative relationship between age and LICI (200 millisecond interval) was also observed in depressed youth in both the right (rs = -0.76, adjusted p =.034; β= -0.35, adjusted p=.004) and left (rs = -0.92, adjusted p =.002; β= -0.25, adjusted p=.001) hemispheres. Conclusion: These findings suggest that younger children have higher motor thresholds. This is more pronounced in depressed youth than healthy controls. LICI inhibition may also increase with age in youth. (shrink)

Since the Nuremberg trials (1947–1949), informed consent has become central for ethical practice in patient care and biomedical research. Codes of ethics emanating from the Nuremberg Code (1947) recognize the importance of protecting patients and research subjects from abuses, manipulation and deception. Informed consent empowers individuals to autonomously and voluntarily accept or reject participation in either clinical treatment or research. In some cases, however, the underlying mental or physical condition of the individual may alter his or her cognitive abilities and (...) compromise the informed consent process. This is particularly true in chronic psychiatric conditions such as Treatment-Resistant Depression (TRD), where individuals may fail to respond to traditional antidepressant treatments (e.g., psychotherapy, pharmacotherapy). Moreover, it may raise further concerns for an individual’s motivation to consent and the level of understanding of the treatment or research procedure. This paper focuses on the informed consent process for Vagus Nerve Stimulation (VNS) in the treatment of individuals diagnosed with TRD. Specifically, the paper addresses how depression may affect the decision-making capacity of an individual and the potential ethical and legal impact of failure to appreciate the seven elements of the consenting process (competence, voluntariness, disclosure, recommendation, understanding, decision, and authorization). To ensure the protection of vulnerable individuals with psychiatric disorders such as TRD and promote ethical behavior in biomedical research and patient care while avoiding potential legal pitfalls, we propose a paradigm that requires a stringent evaluation process of decision-making capacity for informed consent. (shrink)