It deals with the intervention on all forms of addiction to substances (alcohol, drugs, psychotropic drugs) and behavior (social, internet, gaming, sex).

The psychology of addictions deals with the pathological and maladaptive relationship established between the subject and an object, which may be a substance, such as alcohol or heroin, or behavior, such as gambling.

This relationship is defined as dependence, when the person cannot do without the object from which he is dependent. Dependency involves a total disruption of the person, motivation and daily life are centered around the object of dependency.

Before dependency is established, there is usually a period of controlled, habitual or problematic use, but not so strong as to cause dependency. The transition from controlled use to addiction is variable, but marks a marked change in the subject's life.

There are two types of dependency: the physical and the psychological.

In the physical dependence the organism of the subject becomes accustomed to receiving the substance, and phenomena such as tolerance and abstinence occur. The subject is so dependent on the substance that the lack of intake produces strong physical symptoms, which can only be calmed by taking the drug. The physical dependence is also highlighted in the fact that the subject needs to take drugs to start the day, often in fact shortly after waking up he feels the need to take the substance.

Psychological dependence includes craving, which is a strong urge to take on the substance. The subject becomes dependent on the pleasant effects that the substance gives him. For behavioral addictions (including gambling) the mechanism is similar: the subject feels the strong need to implement the behavior (e.g. gambling), which can be calmed only by implementing the behavior from which he is dependent.

In this case from the physical point of view we are dependent not on a substance that is taken, but on the physical and mental well-being due to the release of endorphins that compulsive behavior induces.

All addictions (especially those from substances) involve the individual as a whole. In fact, the body receives a substance that interferes with its chemical activity, creates dependence, produces damage and changes to the physical organs and symptoms due to the use and abstinence of the object of dependence.

The psychological sphere is involved in the obsessive thoughts inherent in the object of dependence, in the compulsions of the behavior of assumption, and in the effects that the object of dependence has on psychic functioning.

Finally, the social sphere is often severely affected by quarrels with partners, family members and friends, illegal behavior to obtain money and the object, a problematic relationship with money and consequent economic problems, which lead to a worsening of quality of life due to the reduced availability of money, possible loss of work or difficulty in finding or permanently maintaining a job and a home.