After one has first developed a physical/mental dependence
to a substance, and abruptly stops taking the substance, one is liable to develop withdrawal symptoms. Withdrawal symptoms vary depending on what substance was being used, quantity, duration etc. Common symptoms include; and are not limited to, depression, body aches, chills, anxiety, trouble sleeping, and constant thoughts of relapsing coupled with a feeling the 'Hair of the dog' myth is a solution. More serious symptoms include: hallucinations, convulsions and possible death. The route of administration (ROA), whether intravenous, oral, or other, can also play a role in determining how severe the withdrawal symptoms will be.