The aim of this review was to investigate informed consent-related issues concerning vagus nerve stimulation and deep brain stimulation in the treatment of psychiatric disorders. We searched the principal medical databases for studies concerning informed consent, as well as ethical and deontological issues in psychosurgery. Data were critically analysed. We also provided guidelines for the evaluation of accuracy of the informed consent in such treatments. Despite major deontological and ethical implications, there is substantial lack of information pertaining informed consent decision-making in psychiatric patients with an indication for psychosurgery. In clinical research studies, deep brain stimulation and vagus nerve stimulation have been mainly used in drug-resistant major depressive disorder, Tourette syndrome and obsessive-compulsive disorder. Existing data on efficacy and tolerability, as well as those studies indicating the risk for incapacity in drug-resistant severe mental disorders, suggest the need to achieve a better understanding of the capacity to consent to psychosurgery in patients affected by mental disorders. Informed consent decision-making in clinical trials of deep brain stimulation and vagus nerve stimulation in psychiatric patients is largely unknown and deserves further investigation.