In a simple word – Yes.
In most cases, your addiction will be used (rightfully so) to discredit your testimony and the medical evidence in your case. If you are suffering from major depressive disorder and an addiction to alcohol, a judge may say that if you stop drinking and receive treatment for your addiction, you would no longer feel depressed and consequently, deny the claim. Similarly, if you suffer from a physical impairment like a heart condition, and admittedly abuse cocaine, the judge may rule unfavorably on the basis that cocaine is damaging to the heart.
In some cases, your addiction may be immaterial to your disability claim. For example, if you have certain aggressive cancers but are addicted to marijuana, the addiction may not be material. The same holds true, for example, if your addiction has caused end organ damage – like cirrhosis of the liver due to alcohol consumption. The key to these cases is that your disability would still exist even if you stopped the addictive behavior.
Regardless of the situation, if you have filed a disability claim and you are abusing drugs or alcohol, you should seek treatment for your addiction immediately and stop using. You should also obtain a letter from your treating physician or alcohol/drug treatment program stating that you are clean and the date you stopped using.
If you are applying for disability and have addiction problems, you may need an experienced Social Security attorney who can help you properly prepare your case and defend your credibility.