Moon or Chandra is associated with emotional intelligence in Hinduism. Thus moon is linked with depression and other mental illnesses. It has been observed that some people become more aggressive prior to Amavasya. This is associated with the moon. Such people should chant ‘Om Namah Shivaya.’
Wear white color clothes and sit in meditation facing east.
Come out of the small world you have created for yourself. Try to see yourself in all animate and inanimate.
Try to focus on the image of Shiva on a calm and peaceful night.
Mediate for few minutes and chant the mantra any number of times you want.
A proper understanding of how your mind works is necessary to overcome the problem. See how thoughts are arising in the mind. Try to find the source. Eliminate all those sources that are temporary and has no real value. Focus on the only real one - Shiva.