If this is your first time using the headset, it's recommended to complete at least 15 sessions according to the treatment protocol (5 times per week for 3 weeks) before deciding if this treatment is right for you.
Usually at around 15 tDCS sessions, users have begun to notice significant positive changes in their depressive symptoms. However, please note everyone is different and some may begin to feel changes earlier and the majority of users continue to feel larger reductions post-15 sessions. These changes have been observed in various tDCS studies (studies can be found here for your convenience).
The best results have been seen by following the recommended treatment protocol which is divided into two phases; Activation and Strengthening. The goal of the full treatment is to stimulate the dorsolateral pre-frontal cortex to both activate and strengthen known neural networks involved in regulating depression.
To see expected and similar results as other users it is important to follow the protocol assigned to you. Adjusting the treatment protocol for individual needs is possible by working with your doctor.