There's a reason why so many people call shopping 'retail therapy" -- research shows it actually can reduce sadness. But why and how? According to this article in The Journal of Consumer Psychology:
"People often shop when feeling sad...[and] sadness is strongly associated with a sense that situational forces control the outcomes in one's life....The choices inherent in shopping restore(s)...personal control over one's environment and reduces residual sadness."
There's nothing wrong with the occasional mini shopping-spree, but don't get carried away with impulse purchases and crazy bargains that make you believe you're saving so much money by buying things on sale that you're actually making money! Watch this short video to understand how not to justify your spending with shopping math: