According to Sadhguru:
The Full Moon (Pournami) Amplifies- Human Energies, Blood Flow, and Mental States, due to increased influence of the moon on this day, making it an ideal time for meditation and spiritual growth.
The Moon's Magnetic Pull influences the Human System on a Continual Basis reaching its peak on a Full Moon Day, causing a natural upward movement of energy, similar to high tides in the ocean.
The full moon DOES NOT cause madness.
Rather, it enhances whatever qualities are already present—Joy, Love, or Madness—offering a natural opportunity for an upward Surge of energy and Heightened Receptivity.
The term "lunatic" is derived from the moon's influence. If one is mentally imbalanced, the full moon can increase that imbalance; however, for a mentally stable person, it can lead to higher levels of Consciousness and Joy.
In the Indian Tradition, this day is especially helpful for inner well-being.
In the Yogic Tradition, it is viewed as a night of great Inner possibility for the spiritual seekers.