YES IT DOES.
"Little Drops can Fill an Ocean".
Most important thing is continuity, if you are exposed to positive thought even for a period of 1-2 mins every day on regular basis, then it works.
Positive thoughts are like a Cleaning Agent which cleans the mind and helps you with positive energy to plan and execute good things in life.
Hope It helps.
"Perpetual Optimism is a force multiplier"