A relevant finding of this work is the continued use of crack cocaine with short time interruptions (less than 10 days) as a protective factor for relapse i.e., long-term abstinence is a predisposing condition for the crack cocaine user’s relapse. This conjures an important reflection when we evaluate that almost all official drug user treatment programs currently available in Brazil admit abstinence as the only plausible goal. No pattern of consumption is tolerated and abstinence emerges as the condition, medium, and purpose of treatment .
Again, concerning the results, the study points the user who did not binge and develop dependence as protective factors. The pattern of binge, dependence and abstinence share the possibility of the developing craving, a factor closely associated with relapse to consumption . Many authors argue that craving is the main reason for relapse [30, 31]. Binge is the pattern of intense, continuous and repetitive crack cocaine consumption, which is defined as “using as much crack cocaine as you can, until you run out of crack cocaine or are unable to use any more” [32, 33]. These irregular cycles of repeated crack cocaine doses, typical of drug dependence caused by craving, are followed by sharp consumption shutdowns, which are associated with withdrawal signs and symptoms, forcing the user back to crack cocaine use .
Before this crack use pattern, it is not difficult to suggest that those crack cocaine users who developed drug dependence and consequently the binge pattern of consumption caused by the crack cocaine craving characteristic will be more likely to relapse to consumption when undergoing treatments in which total abstinence is required as a “cure” of dependence. After intense periods of uncontrolled consumption (binge), maintaining total drug abstinence is supposedly a tremendous effort by a crack cocaine user, so much so that Marlatt  labels it as a high-demand approach. The author also adds that drug abstinence can be associated with relapse and is a barrier to access and continuity of treatment.
Possibly, controlled use of the drug, which would facilitate user’s reintegration into society, with a family, job, friends, and so forth could be a more effective strategy to repress relapse in the case of crack cocaine. In a study of the characterization of the culture of crack cocaine use in São Paulo, Oliveira and Nappo  identified the controlled pattern of crack cocaine use, which was based on harm reduction strategies, comprised the non-daily drug use and was commonly reconciled with pre-existing social activities (regarding family, school and work activities), protecting the user from marginalization. According to these authors, users maintained this controlled consumption from the internal protective factors they developed from their own beliefs and values.
Another element pointed out by this research that deserves attention is marital status as an essential condition of interference in relapse to crack cocaine use. Single participants with a steady relationship or separated/divorced were more likely to show non-relapse than single without a steady relationship. Several authors have shown the protective role of the family for drug use [36, 37]. Sau et al.  confirm this assertion through the results of their research with crack cocaine users, in which a smaller number of cases of relapse occurred among those who were not alone, that is, they counted on the support of a partner or the family. However, the result obtained in this study does not follow this pattern, or at least seems contradictory at first, when it reveals that separated/divorced users are also more likely to not relapse. One possible explanation for this would be the existence of disharmony in the relationship which led to separation or divorce. Some authors state that 75% of relapses occur, among other causes, due to interpersonal problems and lack of family and social support [39, 40]. These causes show that the family does not always have a beneficial or protective role vis-à-vis drug use. Marchi et al.  concluded that families of crack cocaine users are poorly bonded, with broken ties of affection among their members. Disharmony, disagreements, intra-family violence are factors that can trigger a relapse.
Continuing the analysis of variables that have shown to be significant though the logistic regression model, users living in places like home or apartment are less likely to relapse (3.1 times) than those who live in the ‘Cracolandia” or the streets. (Table 5)
Authors such as Halpern et al.  affirm that there is an association between homeless people and the use of illegal substances, mainly crack cocaine, as well as with diseases such as HIV, hepatitis and tuberculosis. The result becomes more evident when one analyzes the characteristics of the Brazilian “Cracolandia” and its dynamics. It is a place that covers four city downtown blocks, with about 500 residents. It receives daily close to 2,000 visitors seeking drugs, especially crack cocaine. It is controlled by organized crime gangs, which operate in trafficking and activities related to the use of drugs, among them crack cocaine. Lack of more effective policing, poverty, unemployment and moral destruction in this place allow users to use crack cocaine on the streets, where many begin to dwell [13, 42]. The presence of the drug, the visibility of consumption and the lack of drug use censorship would hardly be a safe setting to prevent crack cocaine use relapse. On the contrary, this place facilitates its consumption . Besides this widespread social vulnerability is the fact that the “Cracolandia”, because of the full visibility of crack cocaine use, can awaken the environmental clues associated with the drug (seeing someone using the drug, contact with the paraphernalia required for its consumption, such as a pipe, visiting the place where they used to consume the drug), which persist during withdrawal, contributing to relapse . Bruehl et al.  and Chaves et al.  attribute to these environmental cues the potential of triggering a craving, which can lead to relapse. Another factor that can contribute to relapse in places like the street and the Cracolandia the actual violence. In their study with crack cocaine users, Yang et al.  confirmed that violence is a predictor of relapse.
Before these relapse-inducing factors, one can easily understand that home, in general, is a more protective environment against relapse. Religion also appears in the results of this research as an important protective factor for relapse, especially Catholicism. Participants of this study who declared themselves Catholics were 2.8 times more likely than non-Evangelicals and 3.8 times more likely than those with other religions to not relapse.
Brazil is the largest Catholic country in the world  and with about 95% of the Brazilian population with high religious involvement . These data show the importance of religion in Brazilian life, especially the Catholic, the most professed in the country. Religion has been evidenced with a positive association with mental health [48, 49, 50]. Sanchez et al.  have shown the relevant protective role played by the Catholic religion regarding drug use, stressing the role of prayer as conversations with God that act as strong anxiolytic and a means of controlling craving. They also found that confession and the consequent forgiveness of own wrongdoings provide users with conditions for a new start and increase self-esteem, reinforcing their distancing from the drug. In a study to evaluate patients consuming psychotropic drugs, Shirama and Miasso  concluded that there was a relationship of higher consumption of these drugs among non-Catholics. These data may explain greater protection of the Catholic faith against crack cocaine use relapse.
Late onset of drug consumption appears to be a protective factor for relapse. This study points out that a 4.3% increased probability of non-relapse is found with each 1-year increase to the age of onset of drug use. This result may be related to the fact that drug use by young people (17 years of age or younger) is associated with the development of psychosocial problems in various areas of life such as behavioral patterns, psychiatric disorders, family system, relationships with friends, work and leisure . Rioux et al.  showed that adolescents (under 15 years of age) who started drug use were at higher risk of developing disorders due to this consumption at 28 years of age, as well as indirect effects such as delinquency and affiliation to deviant groups of friends. According to these authors, the symptoms caused by the abuse of any drug arising in adulthood are reduced by 31% for each year of delayed drug use onset in youth. In summary, the severity of the symptoms that appear in an adult drug user is related to the age of onset of drug use, that is, the sooner this drug starts, the higher the complications, including relapse.
The results of this work confirm crack cocaine user’s tendency to relapse to drug use in the first months of withdrawal, as described in the literature [15, 18]. Of the 700 crack cocaine users participating in this study, only 7.1% did not relapse. Several characteristics of the sample coincide with the Brazilian crack cocaine user’s pattern found in the National Survey on Crack Cocaine Use developed by the FIOCRUZ  reinforcing the results presented.