The definition of substance abuse may simply be described as isolating oneself from the environment through the harmful use of a substance. In addition to alcohol and drugs (illegal or not), some substances are not drugs at all. 

Below are 20 self-assessment questions to ask a substance addict;

1. What is your average frequency of using drugs that are not prescribed by your doctor or at higher doses than is recommended?
2. Are you ever affected by medical conditions such as seizures, flashbacks, and blackouts that are linked to your drug use (in your opinion)?
3. When you were under the influence of drugs or alcohol, did you ever feel guilty or ashamed about your behavior?
4. Are you losing interest in other activities or noticing a decrease in your passion as a result of using or drinking?
5. After drinking a lot or using or not using for a while, have you ever experienced shakes or trembling?
6. Have you ever had a drug or alcohol-induced “blackout” or a time you can’t remember?
7. Despite friends or family suggesting you stop; do you continue to consume alcohol or drugs?
8. When you tried to limit or control your consumption, did you try different drinks or drugs or change your usage patterns?
9. Does anyone ever suggest you quit using drugs or alcohol?
10. In the last year, how often did you abuse prescription drugs prescribed to you by your doctor?
11. What financial, legal, or marital issues have you experienced because of your use?
12. Are you sneaky about your use or do you hide it?
13. Is it uncomfortable for you sometimes if you don’t have access to alcohol or your drug?
14. Are you an alone user or drinker?
15. Is it easier for you now to drink more and use more without feeling it, compared to when you first tried it?
16. Under pressure, anger, or depression, do you drink more than usual?
17. Do you have a job in danger because of drinking or using?
18. What time of day do you want to drink or use?
19. Have you suffered from illnesses such as nausea, vomiting, or paranoia because of your drinking or drug use?
20. How difficult is it to have fun without drugs or alcohol?