Addiction is generally described as an overwhelming desire to engage in a particular behaviour despite on-going negative consequences. In addition to drug or substance use, the word addiction is sometimes applied to compulsive use of the internet or compulsive sexual activity.
In regard to the treatment of drug addiction, clinicians generally prefer the term 'substance dependence' which has a more specific meaning and is defined by certain criteria. The first point to note is that substance dependence can be psychological, physiological or both.
Physiological Dependence:
Physiological dependence is defined by 'tolerance' to a particular drug whereby increased amounts are required to maintain the desired effect; and 'withdrawal' symptoms, whereby not using it causes severe physical discomfort.
Different drugs induce different levels of physiological dependence. Opiates and benzodiazepines can produce severe withdrawal symptoms, while withdrawal from heavy cannabis use is relatively harmless - generally poor sleep and/or irritability for a few days. Withdrawal from methamphetamine is also harmless - generally characterised by low mood and the need to sleep for a few days. On the other hand, withdrawal from heavy alcohol consumption can be extremely debilitating and can cause convulsions and even death.
Of course, drugs that cause physiological dependence also induce psychological dependence.
Psychological Dependence:
Psychological dependence can be described from a behavioural perspective as a pattern of compulsive drug use, characterised by an overwhelming involvement with the use of the drug, a willingness to go to great lengths (often illegal) to secure it's continued supply, and a high tendency to relapse after it's withdrawal. There are often unsuccessful attempts to cut back or stop and, in more serious cases, dependence may lead the 'addict' to give up other activities he/she used to enjoy. These are the main features of psychological dependence.
THE DIFFERENCE BETWEEN ABUSE & DEPENDENCE
Obviously not everyone who drinks has a problem with alcohol, and not everyone who has a problem is necessarily dependent or 'addicted'. For instance, many if not most adults in western countries try alcohol at some point in their lives, but only about 25% develop alcohol problems - and only 10% to 15% will become alcohol dependent.
Substance dependence is the clinical or medical description of addiction. There are seven criteria which counsellors or doctors use to assess whether someone is dependent: two of the criteria describe physiological symptoms and the other five describe psychological symptoms. If the user meets any three criteria, a 'diagnosis' of substance dependence is made.
Substance abuse is a clinical description of alcohol or drug problems which are not serious enough or not frequent enough to meet the criteria for dependence, but are still severe enough to cause some distress. There are four criteria for abuse: if the user meets any one criteria, a 'diagnosis' of substance abuse is made.
To see the list of criteria for substance abuse or substance dependence, click on Self-Assessment. The specific criteria for both substance abuse and substance dependence are available as a download.
FACTORS WHICH CONTRIBUTE TO THE DEVELOPMENT OF DEPENDENCE
1) Genetic Inheritance:
Most of the research that has been done about the genetics of addiction has been done on people with alcohol problems. The extent to which this research can be generalised to apply to other drugs is unclear. Nevertheless it would not be unreasonable to assume that if there is a history of drug use in your family, you may be more at risk. Further research with different drugs may one day clarify the extent to which this assumption is valid.
What is clear from the research is that if there is history of heavy drinking by grandparents and parents in a particular family, the children from this family have a much greater chance of developing alcohol problems than someone without such a family history.
One of the sources of information for this comes from studies done with twins. When one of the twins from an "alcoholic family" is adopted out at birth and placed in a family which doesn't drink, statistically significant numbers of such children still go on to develop alcohol problems. So even though one of the twins was removed from the original family and raised in an alcohol free environment, both twins have a similar tendency to develop alcohol problems later on in life.
2) Invalidating Childhood Experiences:
When children are seriously abused, when their emotional needs are neglected, or their psychological experiences of life are invalidated, their self-image and self-esteem are usually profoundly affected by such experiences. It seems that children from such backgrounds who have experienced early psychological damage, are far more likely to develop problems with substance abuse as they grow up than children who are psychologically healthy.
The way this seems to work is that when children with seriously negative life experiences begin experimenting with alcohol & drugs as teenagers, the pleasure they derive from being 'stoned', 'out of it' or 'high' tends to have greater impact and meaning for them than for children who are psychologically healthy. For psychologically damaged youth, the pleasant experience derived from being stoned or intoxicated may provide the first real relief from years of emotional distress.
It is not surprising that when someone who has endured years of emotional pain or distress finds a substance that actually brings temporary relief, they want to use it again when the 'high' or the relief wears off. For individuals who are vulnerable, the experience of such relief can therefore be a powerful addicting experience.
3) The Power of Peer Pressure:
To some extent we are we are all influenced by other people, and look for acceptance from family, friends and colleagues. As teenagers we go through the developmental process of separating from our parents and establishing our own identity. In the process of breaking free from our parents, acceptance by the peer group sometimes become more important to a teenager than acceptance by the parents.
While we all need some measure of acceptance from others, those teenagers that come from troubled family backgrounds where there has been neglect, invalidation or abuse are likely to be especially vulnerable to the need for acceptance from their peers.
If you want or need to be accepted by your friends and they all smoke 'dope', then what choice does a psychologically immature teenager have. Cannabis is 'cool' and everyone is doing it, right? So the need for acceptance by one's peer group is a powerful environmental or social influence which often contributes both to the start and then the continued use of cannabis and other drugs.
4) The Impact of Substance Use on The Teenage Brain:
Human beings are born with literally billions of brain cells. However at birth, the cells are not all connected. Whenever we learn a new skill in life new connections between brain cells, known as neural pathways, are established or strengthened. To some extent this process goes on throughout life, but research suggests that the bulk of the development of new neural connections is done up to and before the age of 25.
So the adolescent brain is still under construction; the neural pathways required to establish impulse control and psychological maturity are not fully developed. As a consequence teenagers are especially vulnerable to the potentially damaging effects of too much alcohol, cannabis or any other drug on the still developing communication systems within the brain.
If heavy substance use doesn't begin until later in life, the pathways and communication systems within the brain are, for the most part, already in place by then. But if you use heavily as a teenager, those pathways may never develop properly and the consequences can last a lifetime. See the section Is Cannabis Harmless? for more information about the potential impact of cannabis on the teenage brain.
5) The Addictive Potential of Different Drugs:
Some drugs are clearly more addictive than others. Some produce physiological dependence, while others are more likely to result in psychological dependence.
Opioids & Benzodiazapines:
Opioids (such as heroin and morphine), and benzodiazapines (such as valium) have the potential to produce both physical and psychological dependence. Tolerance develops quite rapidly and withdrawal generally causes intense anxiety and physical distress.
Methamphetamine
Tolerance to methamphetamine also develops quite rapidly. Withdrawal symptoms include depression and fatigue and this can last for a few days or even weeks after long term use.
Because of the addictive potential of these particular drugs, most people who take them on a long term basis would become addicted, whether they had invalidating childhood experiences or not.
Alcohol:
Most people can have a few drinks every week over a period of many years without developing dependence on alcohol. Others will become dependent quite rapidly because of their particular genetic or psychosocial vulnerabilities. For those who drink heavily, withdrawal can be very difficult. Alcoholics tend to get the 'shakes' and 'sweats', and abrupt withdrawal can cause convulsions and even death. In severe cases, withdrawal or detox is generally done under medical supervision.
Cannabis:
Cannabis does not produce the same level of physical dependence as more addictive drugs, but it can create quite strong psychological dependence. Long term users often find it hard to give up. Withdrawal symptoms include irritability and difficulty sleeping, but this usually lasts only a few days.
