Tolerance and withdrawal.
Abuse becomes addiction.
When someone is abused and constantly overuse some chemical substance his body is bombarded by millions of dangerous molecules. Sometimes those molecules cause damages inside by destroying cells and tissues. Organism has to fight with it because it's really like a war. There is one mechanism against addiction developed inside us – the so-called 'tolerance'. Tolerance is a special system of biochemical responses physiologically built by body to defend itself. But tolerance is going to revolve against an addicted person.
Abuse, addiction, dependency? – names soup
Term 'substance abuse' is generally confused with chemical dependency, substance dependency, substance addiction, drug dependency or drug addiction. As you can see there is a lot of words which are closely related to what we are focused on. If you have read two previous articles – Substance abuse basics and Psychological addiction – you may guess what is the difference between abuse and addiction and what is the difference between abuse and dependency. Some distinctions between appropriate terms are under current debate and definitions sometimes remain still unclear.
Tolerance – metabolic tolerance and tissue tolerance
Let's emphasize: abuse is not an addiction. Still not. It's first step from addiction. If you overuse some substance for a some period of time regularly – you can become addicted. When abuse is long in time your organism is balefully learning this activity. Organism starts to recognize chemical substance, that you use and unfortunately like, as a natural and indispensable part of its running. This learning – building up a tolerance – is not fine even if it sounds good. From medical point of view there are two mechanisms of tolerance – metabolic tolerance and tissue tolerance. Metabolic tolerance occurs when body has learnt how to convert substance of abuse into other, in manner that is faster than before. Hence, substance disappears quickly and one who's addicted needs more. Tissue tolerance occurs when substance abuse leads to decrease in receptors sensitivity so that those receptors are more indifferent or 'apathetic'. Tolerance does not develop in reference to all substances of abuse or addiction just like addiction. But often tolerance is compounded by dependence.
Psychological tolerance
Despite those physiological (physical) mechanisms of tolerance our brain, our impressions, our expectations – I mean our whole psychology – are also influented by abuse. It is intuitive and simple to understand that any pleasure seems to be bigger when we experience it only from time to time. And when something becomes part of everyday life you can get use to it and do not find it so extraordinary any more. Such a psychological phenomenon – decrease in intensity of impressions, feelings and sensations – in reference to chemical substances abuse and addiction is often called psychological tolerance.
(Thin) border between addiction and abuse
When tolerance and chemical dependency to drugs comes to play your problem is not an abuse any more. It's addiction. Addiction as I said in previous article is a psychological state – something inside your head. You continue using substance though you are conscious that there are negative consequences – social, medical, financial, legal or others – of what you do. But some substances alter not only your psychology but also your physiology. This is another face of addiction – the so-called substance or chemical dependency. Tolerance mechanism is being developed in your body pararelly. Addiction usually is a mixture of those two counterparts:
- psychological addiction and psychological tolerance,
- physiological addiction (chemical dependency) and physiological tolerance.
Addiction self-propelling feature
When your organism built tolerance to alcohol for example, reactions, that you experience after introducing it into you body, are smaller than before and still decreasing. It means that because of tolerance someone who abuses alcohol and now becomes addicted have to enlarge doses he used to take. It's required to achieve the effect which was possible to reach with much smaller amounts of substance before. So: you need more and more and you take more and more...
more about withdrawal in 'Chemical dependency concept' article
