The term dual would refer to one being dependent upon two different drugs classes at the same level of dependence = being a alcoholic and a herion addict for example.
By definition any addiction to anything is bad.
The definition of alcohol addiction is as follows: alcohol addiction is when alcohol has interfered with someone's body and mind chemistry so much that he/she can no longer function normally without the use of alcohol.
I don't know for sre but i think it is where you are addicted to both drugs and alcohol
One can find the definition of the word "addiction" on a variety of online sources. Such sources include Psychology Today, Wiktionary, Dictionary, and Wikipedia.
Addiction
Addiction is when a person becomes so accustomed to the pleasurable sensation of doing something that he or she continues to do it over and over, even after it has ceased to be pleasurable.
Inability to approach normal functioning without heroin in your system.
Dual dimensions in engineering is when both the English system's unit for the dimension and the metric system's unit for the dimension are shown together as two stacked dimensions.
These are specified in great detain in DSM-IV, which is available at most libraries.
Addiction to the consumption of alcohol
Lichen is a dual organism which is made of a fungus and an alga, associated in a mutually beneficial association.
In IT field, dual band is associated with the wireless router. This router handles frequency bands of 802.11. Dual band routers support 11a users in 5GHz band and 11b/g users on the band of 2.4GHz.