The definition of abnormal psychology is generally from five angles.
1. Statistically deviated from the normal state 2. Social acceptability and adaptability. Functionality (for example, personal perception of reality is problematic) 4. Sensitivity (for example, personal pain) 5. Consistency and stability.
The main consideration should be activity or behavior addiction, so this aspect should mainly be 1, 2, 4.
But then again, it is really difficult to define normal and abnormal in real life. What is abnormal in one cultural environment may be normal at another time (place).
If we must say whether there are principles, we can refer to whether the behavior has an impact on personal daily life. If it obviously affects normal life, it is abnormal in a sense and needs relevant intervention and treatment. On the question of definition. DSM and ICD in psychiatry will contain related terms (substance abuse and dependence), which should be an authoritative definition.
Broadly speaking, substances and behaviors that can stimulate the brain to produce dopamine are addictive. Including high-sugar foods, cigarettes, alcohol and various drugs.
This is a defect-in human physiology-that some substances are both toxic and addictive.
If you are addicted to these things, you will not be able to control your repeated intake until you reach the lethal dose. Similarly, some behaviors are addictive, such as gambling. On the other hand, according to this definition, interests such as learning and scientific research are also addictive. But the difference is that these things are positive behaviors (except some folk themes). All of the above are harmful.
And each unit of these substances and behaviors can produce little dopamine, while each unit of alcohol, tobacco and poison can produce a lot of dopamine, so people are easy to take bad but difficult to take well. But if you can make good use of this substance and principle, you can achieve great success.