The cycle of addiction for all types of drugs - heroin, cocaine, crack, amphetamines, barbiturates, alcohol and cannabis/marijuana is essentially the same and based upon nature and nurture. This comprises three features
1) chemical dependency ; 
2) learned behaviours and habits ; 
3) denial of both need and habit. 
Although there are important differences in the features of addiction to cocaine, heroin, amphetamine or alcohol, these features are basically differences of form and not one of essence.  Furthermore, these difference become less relevant where people are cross-addicted to one or more substances.

One of the principal difference between so-called « hard » and « soft » drugs, 
is the speed of the addiction process. Whereas the phase of chronic alcoholism may take 5, 10 or 20 years to develop, total chemical dependency can be achieved 
from day 1, 6 months with drugs such as heroin and cocaine.

Initially, drugs are used for pleasure and relief. However, they work on the basis of ever-increasing investment for ever-diminishing returns.

Whatever the individual time scale, drugs result in increased pain and less and less pleasure on a physical and psychological level, and the addict needs ever greater amounts of the substance to ward off the torture of withdrawal, and achieve a level of bearable « normalcy ».

Modern medical evidence proves that addiction is a biologically-based illness, 
to which psychological and sociological factors are important, reinforcing factors. 
Psycho-sociological factors may play a more or less important role in starting the addiction (depending on the individual), but, at root, we are dealing with a physiological illness, based on chemical dependency, acquired through "nature", i.e., genetical inheritance predisposing the person’s body chemistry to addiction ; and "nurture", i.e., behaviours and habits that lead to a fundamental change in the body chemistry, which results in dependency on the physical and psychological level. Consequently, the body is, or becomes, susceptible to all addictive substances. Studies in Dublin, Ireland, have shown that heroin addicts have a greater tendency to come from families, where one or more parents were alcoholics.  However, you do not need to have a genetic disposition to get addicted, this only « helps » the drug to do its work. Furthermore, once hooked to one main addictive substance it is frequent and easy to become dependent upon another.

All drug use can lead to serious brain and organ damage and death. On the psychological level it leads to depression, neurosis, paranoia, psychosis and suicide. Recent scientific research shows that all drugs work on the same neurological pathways and key areas of the brain, especially dopamine receptors and the limbic system.  A famous breakthrough, in this respect, was made by accident in Texas, when a specialist physician carried out an autopsy on four dead men. The physician, a world authority in the effects of heroin on the brain, concluded in her report that all had died as a result of heroin damage to the brain. To her surprise, she was later informed by local police that none of the deceased were heroin users, but all were alcoholics.

The limbic system is our most primitive response mechanism in the brain, which works on the instantaneous satisfaction of needs, normaly for survival - hunger/eat, danger/attack-run.  Addiction tricks it into equating drugs with pleasure/relief, and even with survival. Faced with the bodily agony of withdrawal the limbic system can override higher brain functions and demand drugs- NOW - by any means necessary !- and this lies at the root of much the social marginalisation and crime committed by addicts.

The most important psychological factor in the addiction process is DENIAL. 
« One/another try won’t harm me », 
« I won’t get hooked like those bums on the street »,
 « look at .... he doesn’t have a problem», « I have a habit not a problem »,
 « I can kick it whenever I want to » etc. 
This maintains and reinforces continued use and dependency.

The cycle of addiction can only be broken by getting clean and remaining totally abstinent from all mind-altering drugs. Many addicts are cross addicted and/or use varying cocktails of other drugs to help them withdraw from their main drug of choice. Barbiturates, amphetamines, alcohol and marijuana, heroin and cocaine are regularly mixed for their countering or complementary effects.

During the 60s and 70s many alcoholics used drugs like valium as a substitute for 
alcohol, some now use marijuana as a supposedly « safe » drug, while not drinking.  The same often holds true for heroin and cocaine addicts.

However, it’s a fool’s solution, which sooner or later leads back to use of the 
original drug of choice. Most often this happens because, under the influence of 
the substitute drug, the addict is no longer in control of their thoughts and actions, 
and- drunk or high - they take their original drug of choice again.

However, the underlying reason for this is that an addict’s body chemistry is addictive and, therefore, hyper-sensitive to all addictive substances. At base, the brain reacts in similar ways to all toxic mind-altering substances, even if the effects of the substance are different. Thus, the brain remains in addictive mode, even if the original drug is not taken. The neural associations and pathways have no opportunity to become disabled and dormant, and instead stay active and alert for the chance to latch back onto the original drug.

For this reason many addicts and alcoholics, have to be careful even when taking 
prescribed medications. For example some alcoholics have reported unpleasant side-effects and cravings following cough mixture, some of which contain small amounts of alcohol.
 

Others have reported a sudden rise in urges and cravings following surgery and medications. Pain killers and sedatives can have sometimes have very bad effects. 
In other words the brain and nervous system is not able to make the subtle 
differentiation between these drugs and the addict's drug of choice, and thus 
believes it is receiving a small or similar form of the original drug, and reacts by demanding more of the real thing.

The underlying psychological factor in this is that, although s/he may not be using the original drug of choice, the addict is still, in fact, in denial. 
« But I never had a problem with alcohol », 
« I don’t fix anymore, but the odd joint is o.k. », 
« I need these just for my nerves/depression ». 
In fact, in the name of abstaining from the main drug, the addict is only perpetuating the cycle of addiction in another form, a cycle within a cycle, and is not at all
breaking away to a new cycle of sobriety and recovery. The only exception to this is where medical proof exists of dual diagnosis, i.e., where the addict is also suffering from mental illness which needs prescribed medication, under the careful control of a specialist.

Since the Cycle of Addiction for drug addicts and alcoholics is essentially the same - 
all addicts must follow the Cycle of Sobriety  which demands 
1) daily acknowledgement of your addictive disorder, 
2) daily acceptance of the fact that you are seriously ill, and 
3) your daily Sobriety Priority, which means - 

TOTAL ABSTINENCE FROM ALL MIND-ALTERING DRUGS

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