Substance use is initially used as way to gain confidence medicate fears and fit into social groups

The statement above is TRUE.
Some individuals start using drugs initially just to boost their confidence level so that they will be able to face the public and perform as expected. This is especially true for upcoming pop musicians who are afraid of facing crowds. But as time goes on, such people discover that they can not possibly do without the use of these drugs.

Imean it could be both ways