A method for treating autism. Light energy is applied externally to a patients scalp on the skull near the frontal lobes. Optionally the light is also applied to the temporal lobes and the base of the brain. The treatment can be enhanced by activating the cranial nerves while the light is applied. In a preferred embodiment the applied light is in the red range and more preferably about of 635 nm±10 nm. In a preferred embodiment, the applied light energy is applied with a pulse frequency or frequencies of 8 Hz, 53 Hz, 73 Hz and 101 Hz. The light can be emitted from the same light emitter or from multiple emitters. Preferably the light is laser light and is emitted as a line from a hand-held laser device, and the line is waved manually across a persons skull in the desired area in a continuous, sweeping manner.
