2-3 times a week sufficient for this. Level released from fat as acute level drops. Stored in all fat and also in the basic building cells of the body. Depends on frequency and on concentration. The more mature the person the less permanent damage.
Symptoms are insidious and subtle and can parallel adolescent adjustment symptoms.
THC exaggerates these symptoms, makes them more profound and often permanent. Saturation in the brain causes memory impairment, concentration impairment and motivation impairment. Can be a major personality change. As the brain level decreased THC moves from other body fat to the brain to keep the brain saturated. Regression to immaturity can occur and can be irreversible.