Drug and alcohol addiction  is arguably the number one cause of death and disability in the world, with tobacco/nicotine addiction killing nearly a half million Americans a year and 5 million worldwide.  When one considers that 90% of the incarcerations, 50% of the psychiatric admissions and roughly 25% of the admissions to medical surgical hospitals are directly the result of addiction, one begins to get a picture of the enormous toll addiction takes on society.  Add in the highway deaths due to DWIs, the spouse and child physical and sexual abuse, even the source of funding for despots and terrorists worldwide, and the scale of the horror is mind-boggling.  
  The term addiction usually refers to the chronic use of one of three kinds of psychotropic substances, legal drugs (alcohol, nicotine), illicit drugs (cocaine, marijuana) or prescription drugs (valium, prozac), in large enough quantities to cause life-damaging consequences in the vocational, academic, interpersonal, medical and/or other dimensions of one's life.  However, the definition of addiction can be expanded far beyond chemical addiction, to include behavioral addictions to sex, gambling, overeating, video games and many other compulsions.  Actually since the cause of suffering has been defined on this website as attachment, or conversely the ending of suffering stems from detachment, a term used in Alanon, the meaning of addiction can be expanded to include anything  which defines happiness as having, doing or being something other than what one currently has, does or is.  When happiness is defined as having, doing or being something more than what the immediate circumstances in life offers in the NOW, the experience of craving can ensue.  Craving is the primary symptom of addiction, and if craving is severe enough, an addict will destroy anyone or anything to get to the object which they are deluded into believing will satisfy their craving and bring lasting, true happiness.
   The notion that lasting happiness comes from having the object of one's craving satisfied is an illusion, because the experience of satisfaction is always temporary.  Whether the addiction is to sex, drugs or rock and roll, it can't bring lasting peace and happiness because it is transient.  Furthermore, the reinforcement of having a craving satisfied, which is stored as a memory as an experience in the past, tends to strengthen the craving of having it satisfied again in the future.  As the cravings thus worsen, one's mind is drawn increasingly into the past memories of the satisfaction of having past cravings satisfied, or future cravings for the next event when the cravings will again be satisfied, and the mind spends less and less time in the NOW or at peace with the way things are.  Addiction can be described as an obsessional state for an object (drug, behavior, anything) in which the mind cannot find peace with the current situation or the NOW.  So critical is this issue to recovery, that in Alcoholics Anonymous, the serenity prayer is generally repeated at every meeting, and the line, "God grant me the serenity to accept the things that I cannot change" is the opening line of the serenity prayer.   
  Any event or person which threatens to interfere with an adddict satisfying their craving risks incuring a "fight (anger - past oriented) or flight" (fear - future oriented) response," a primitive mostly norepinephrine-caused surge from the locus ceruleus in the reptilian brain, from the addicted person.  Interfering with an addicts access to drugs and alcohol, or a power addicts ascent to political dominance can get you murdered, and it is all driven by this primitive, norepinephrine, fight or flight, survival reaction.  As cravings worsen, addicts find less and less serenity for the NOW, their lives become increasingly dominated by fear (future) and resentments (past), and the illusion deepens that only the object of their addiction (gambling, cocaine, codependent control) can calm the stress of the "fight or flight response." 
  Actually, all discussion up to this point is psycho- or socio-babble, and does not get to the heart of the matter.  Thanks to the advances in the neurosciences, we can drop all the nonsense and superstition and discuss the cause and cure of addiction in scientific terms.  Actually, biochemical imbalances in the eight neurotransmitters of NOW (see table below) are the driving force behind all addiction and cravings.  When they are deficient and/or unable to oppose the norepinephrine-driven fear and anger, the addicted person finds it extremely difficult to not satisfy their cravings. Addicts become progressively powerless over the dictates of their imbalanced brain chemistry, and if you don't believe that, try a simple experiment and hold your breath for as long as you can.  I guarantee you that as the brain nutrition worsens (oxygen lessens), the brain toxicity wosens (carbon dioxide increases) and the neurotransmitters get imbalanced, you will become progressively powerless over what your brain chemistry will force you to do - breath. As addiction worsens due to nutritional deficiencies, toxicities and neurotransmitter imbalances, the experience of serenity or living in the NOW (called "one day at a time" in AA terminology) becomes increasingly impossible, suffering worsens, and it is all caused by insufficient activity of the  neurotransmitters of NOW.