Abstract Introduction: Deep Brain Stimulation can directly alter brain activity in a controlled manner and the effect is reversible. The mechanism is that the electrode acts locally on neural activity, which is transferred to monosynchronous and multisynaptic network connections. Methods: We present studies conducted on a group of patients that show an improvement in mental state after Deep Brain Stimulation. Material: The diseases we included in our work are: Obsessive-Compulsive Disorder, Eating Disorder, Depression and Bipolar Affective Disorder. Discussion: The use of deep brain stimulation can inhibit development of acute state of patients and improve both psychiatric features and the time of remission. The results indicate the greatest effectiveness of Deep Brain Stimulation in Obsessive-Compulsive Disorders. Conclusions: Brain stimulation may be a promising therapeutic target in mental illness. In a properly selected location, it can contribute to a significant clinical improvement however further research in this direction is necessary.