Answer:
Initial use of the substance / experimenting with it / trying it out or emotional trigger (read explanation, especially the bold parts!! read the "note" too!)
Step-by-step explanation:
The very first step to addiction is the initial use, or actually trying and experimenting with the substance. It can be as simple of an action as taking a sip of the drinking or smoking the cigarette.
Then comes abuse, where the person continues to use the substance to get the high and feeling of euphoria, or to escape from reality. This is followed by tolerance, where the user's brain does not produce as much dopamine as it used to, and the user begins using more drugs or a higher dosage to get the same high feel. Then comes dependence, where the user becomes dependent on the drug. The user may begin to use the drug in inappropriate settings, experiencing relationship problems, becoming less social, experiencing symptoms of withdrawal, and increasingly craving the substance and spending more time looking for it. This stage is followed by the addiction, where the addict is aware of their addiction and knows they have a problem. They use more of the substance, are unable to stopping their use of the substance, experience even more cravings, spend too much time using the substance, experience more withdrawals, continue to use it in inappropriate settings or even when it causes relationship problems and health issues, replacing normal activities with substance use, and build up a higher tolerance. The final stage is the relapse. This is where the user is experiencing severe withdrawals to the point that it is exceedingly overwhelming, causing the person to seek ways of retrieving the substance. They try to get the emotional support of the drug again, causing them to go back to the dependent stage of the addiction cycle, holding them back from recovery.
However, if your curriculum is referring to one's emotional response during the addiction cycle, it goes a little bit like this:
First comes the emotional trigger, the feeling often rooted in trauma and pain. This can be conscious or unconscious, and it may take a while for the user to identify the emotional trigger. This usually fuels the addiction cycle, as the user wishes to escape from reality or get that feeling of high.
Second is the craving, in which the user is emotionally triggered and attempts going into defense mode, where they wish to protect themselves from something unwell by avoiding it. Their mind and body begins to believe that using the substance is the best way of escaping the unpleasant thoughts and feelings, and the emotional trigger transforms into a huge craving to use the substance, which to them becomes even more important than life.
Third is ritual, where the addict has a craving and follows a ritual as part of the addiction. These "rituals" normally consist of how the user acquires the substance and uses it. For instance, a drug user may always go to a specific place to procure the substance in the morning before binging on it for the rest of the day.
Fourth is use. This is where the user uses the substance to get away from what’s bothering them.
Lastly comes guilt. This depends on each user, as some people may feel guilty right after using the substance, while others feel it later. All the guilt may end up as an emotional trigger, which causes them to repeat this cycle again and use the substance even more.
Note: The response to this question really depends on how many steps in the cycle your course talks about. Some people learn there are four steps, others learn there are six. However, this is usually the first step in most curriculms. It also depends on whether you are referring to the first step of getting addicted or your response/emotions/etc during addiction.
Hope that helps!
Disclaimer: I am not responsible for anything you get incorrect, as I only have the context and information you provide, and I give my response based on my knowledge supported with credible information from experts and online professional articles.
Images do not belong to me. Credits to the SpecialCare Hospital Management and Mind Body Health Associates for the images. Thank you AYLST Health and a rehab center for the information.