Warning! This post is very old and may contain information or opinions that are no longer valid or embarrassing.
One year ago, I went back to working in addictions psychiatry. I think I have few points that I would like to share with everyone. And since so many people use drugs perhaps I can help answer some of your questions:
Addiction can be worse than cancer. If cancer eats away parts of the body, addiction eats away your life and the life of people surrounding you.
Addiction is a chronic psychiatric condition that varies in severity. Not everyone who uses drugs or alcohol will become addicted.
It is a psychiatric condition that demonstrates the complex interplay between biological, social and psychological factors and affects the person's thoughts, emotions, behaviours and physical health. No other psychiatric disorder demonstrates this as much.
All drugs are the same if the person develops an addiction. Alcohol included.
Some drugs can directly kill you. Overdose is an inaccurate term. Heroin, for example, stops the basic centres in the brain responsible for your breathing (it was originally marketed as a cough suppressant). It is very hard to predict which dose will make this happen. There is no pre-set dose to go over. Cocaine on the other hand directly damages your heart which can lead to sudden death. Again hard to predict when this will happen. Mixing drugs is a recipe for faster damage.
Addiction to socially accepted drugs such as alcohol and cannabis can have the same destruction of a person's life as hard drugs.
Drugs work differently on the brain but ultimately they all affect the reward pathway. The reward pathway is how we feel pleasure from our senses and actions (i.e. eating a nice meal or sex, etc..). Our senses and actions can give us limited reward. Drugs offer unlimited reward.
Reward is essentially how all fairly complex animals learn. Young age is when we learn very quickly. Taking drugs to deal with life is similar to using video game cheat codes to finish a level. It offers a short cut to dealing with problems.
If you learn this short cut at a young age, it becomes very difficult to unlearn it and then start learning new ways of dealing with life from scratch.
The critical age for developing an addiction is 12-24 years old. So if you're interested in altering your mental state try to do so after that age. Be very worried if you like the drug (more than anything else). You can still develop an addiction at any age but it is less common.
We will always have the drive to alter our mind. Either to experience pleasure or escape unpleasant feelings. Therefore, trying to prevent access to drugs is futile. The money could be better spent on treatment and research.
Only very few people can afford treatment and addiction treatment is still in the dark ages. Treatment from addiction is not just withdrawal from the drug. That is the easiest part. Many people recover but it is important to understand that recovery from a chronic condition is about improvement in a person's functioning and quality of life.
One reason that makes treatment difficult is that addiction is difficult and frustrating for other people to understand. Which makes it hard to empathise with someone who is destroying his or her life. This is part of the stigma surrounding the condition and that is why recovered addicts have a major role in helping people recover and helping society change.