https://orcid.org/0000-0003-3815-4489
Abstract
Introduction
Cases of amphetamine-type stimulants (ATS) use have been increasing over the past decade. Cravings are considered a causal factor for recurrent relapses in ATS use cases. The absence of questionnaires measuring cravings for ATS in the local population necessitates the creation of one, especially considering the rising number of cases.
Objective
This study aimed to adapt and validate the Cocaine Cravings Questionnaire into a questionnaire suitable for measuring cravings for ATS in the local population.
Methodology
The original questionnaire was adapted by substituting “cocaine” with “ATS”. The process involved a back-to-back translation, followed by a round of face and content validation. The participants included people who use drugs (PWUD) with a history of ATS use recruited from rehabilitation centers in Malaysia. A set of questionnaires consisting of demographic items and the adapted ATS Cravings Questionnaire (ATS-CQ) were given.
Results
This cross-sectional study recruited a total of 205 PWUD, mostly single men, with a mean age of 33.32 (s.d.=13.14). The mean age of ATS initiation was 22.89 (s.d.=9.39), with a median duration of ATS use of 60 months (IQR=24.00, 120.00). The adapted questionnaire received a good score for content validation. Unlike the original, this adapted version was found to have only three factors showing good internal consistency, ranging from 0.707 to 0.918 for all three factors. Test-retest reliability also showed good results, with an interclass correlation coefficient of 0.875 (95% CI=0.835, 0.905).
Conclusion
The translated ATS-CQ has been finalized and deemed valid and reliable for use among Malaysian substance users to measure ATS cravings.
Introduction
Cravings, by definition, are impulsive and difficult-to-repress urges to use substances. The term has been defined and redefined by several studies and theories. Generally, however, cravings can be described as the “conscious experience of a desire to take a drug”, as stated by Drummond (2001).Citation1 It represents an emotional-motivational response leading to drug-seeking behavior.Citation2 Theoretically, craving is an essential component of substance dependence. It is theorized that substance craving acts as a major causal factor for continued substance use and relapse among individuals attempting to achieve abstinence.Citation3
In the latest iteration of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), “cravings and urges to use the substance” were added as new criteria for diagnosing substance use disorder (SUD).Citation4 This addition was significant as it notably enhances the diagnosis of SUD. Cravings, as a diagnostic criterion, plays a crucial role in improving the accuracy of diagnosing SUD when using DSM-5. Regardless of whether cravings are moderate or severe, they predict subsequent use of tobacco, alcohol, cocaine, cannabis, opioids, and heroin, with odds ratios ranging from 4.2 to 234.3.Citation5 However, substance craving also poses challenges for successful treatment, significantly increasing the risk of relapse among those undergoing treatment.Citation6 A local study found that levels of substance craving remained moderate to high among individuals who were incarcerated and were correlated with higher risks of relapse.Citation7
The cocaine craving questionnaire (CCQ) is a 45-item self-rated questionnaire developed by Tiffany et al (1993) that measures current cravings (CCQ-Now) and general cravings (CCQ-Gen, average cravings over the period of one week) toward cocaine. The questionnaire is divided into five factors: “Desire to Use Cocaine”, “Intention and Planning to Use Cocaine”, “Anticipation of Positive Outcome”, “Anticipation of Relief from Withdrawal or Dysphoria”, and “Lack of Control Over Use”. However, the CCQ-Now only comprises 41 items distributed across four factors, with an alpha value of 0.93.Citation8
Amphetamine-type stimulants (ATS) are psychostimulants derived from amphetamines. These substances act on the central nervous system by eliciting an increased concentration of dopamine. There has been a rampant increase in ATS-related hospital visits, with ATS overdose-involved cases rising by 20.5% in 2017 compared to 2016 in the United States.Citation9 This increase is possibly due to the global increase in the supply of ATS. According to the United Nations Office on Drugs and Crime (UNODC), global seizures of ATS have increased sevenfold from 2009 to 2018.Citation10 This trend is also observed locally, where there has been a shift from opiate seizures to ATS seizures over the past decade. The number of individuals caught using ATS increased by almost 25%, whereas opiate users decreased by 75% in 2020 compared to 2016.Citation11
Substance use among youths is exhibiting a concerning trend, with the age of first initiation showing a downward trajectory locally. Interviews conducted among affected youths have indicated that children are initiating substance use as young as 12 years old.Citation12 A recent large-scale health and morbidity survey conducted by the Ministry of Health Malaysia reported that as many as 100,000 adolescents have experimented with substances, and approximately 60% of them are currently still using.Citation13 According to Wahab et al (2021), among juvenile offenders with a history of substance use, the prevalence of amphetamine-type stimulant and cocaine use was 55.2% and 10.4%, respectively.Citation14
Furthermore, psychostimulant use among youths has been associated with significantly worse outcomes, especially when initiated at a younger age. Issues such as a higher likelihood of conduct disorder diagnosis and impaired cognitive functioning are more common among these affected youths.Citation15 A local study has also found that methamphetamine-induced psychosis tends to occur more frequently in the younger population.Citation16 Additionally, other issues, such as risky sexual behavior and adolescent pregnancy, are more prevalent among youths who use methamphetamine.Citation17 Thus, managing these cases becomes significantly more challenging, especially considering the teratogenic effects of certain medications used in treating methamphetamine-related problems.Citation18
Given the similarities between cocaine and ATS as psychostimulants, researchers have endeavored to adapt and validate the CCQ for ATS use among Malaysian youth. This is particularly significant due to the lack of locally validated self-administered questionnaires addressing cravings for ATS. The objective of this study was to adapt, translate, and validate the CCQ-Now into the Malay language for use in assessing ATS cravings among Malaysian youths.
Methodology
Ethics Approval
The study obtained ethics approval from the Universiti Kebangsaan Malaysia (UKM) research ethics committee before commencing data collection. All respondents were informed about the study and provided written consent to participate. For respondents under the age of 18, written consent was obtained from their guardians. This study adheres to the principles outlined in the Declaration of Helsinki.
The recruitment and data collection began on January 3rd, 2022, and concluded on March 4th, 2022.
Translation
Before the translation process, all items were reworded to pertain to ATS instead of cocaine. Additionally, a list of common ATS used locally (including local street names) was provided before presenting the questions to the study participants.
The translation process followed the guidelines for cross-cultural adaptation of questionnaires by Guillemin et al (1993).Citation19 Medical practitioners who were familiar with the terms used in the questionnaire and proficient in both English and Malay were recruited to conduct a back-to-back translation. This process involved translating the original English set of items into Malay, followed by a blinded translation of the Malay set back into English. Subsequently, a review committee consisting of the researchers and translators was formed. The back-translated items were reviewed for any inconsistencies against the original questionnaire.
Item 33, “I want ATS so bad I can almost taste it”, had to be reworded during the translation process into Malay because the initial translation did not retain the intended meaning of the phrase. However, the remainder of the questionnaire was translated well into Malay.
Face and Content Validation
A panel of six subject matter experts, comprising a mix of psychiatrists and psychologists, was invited to review and provide their opinions on the items and language used in the questionnaire. Each expert rated each item based on its relevance to measuring cravings for ATS, using a rating scale ranging from one for “Completely Irrelevant” to four for “Completely Relevant”. The proportion of experts giving a rating of three or four was calculated for each item. A content validity index score above 0.83 indicates that the items are valid for this questionnaire.Citation20 Additionally, the expert panelists were asked for their subjective opinions on the use of the Malay language. Comments and suggestions to change the wording were collected and reviewed jointly by the panel and researchers.
Sample Recruitment
Due to the nature of the questionnaire, only individuals with a history of ATS use were recruited. They were selected through convenient sampling from various treatment centers for substance use disorder. These centers are privately owned and specialize in treating substance use disorders, located in Kuala Lumpur, Malaysia. The inclusion criteria for participants were active users of any type of ATS (with a history of use within the past year), proficiency in reading and writing in the Malay language, and were not actively experiencing any stimulant-induced psychiatric symptoms.
The total number of samples recruited adhered to the recommendations by Suhr (2006), which suggested a minimum of five samples for every item (5:1). Since the ATS cravings questionnaire was adapted from a 41-item CCQ-Now, the minimum required sample size was calculated to be 205 respondents.Citation21
Test-Retest and Internal Reliability
The test-retest reliability was conducted one week after the initial test. This involved measuring the intraclass correlation coefficient (ICC). The internal reliability was assessed using the first test completed by the respondents, and it was measured by calculating Cronbach’s alpha value.Citation22
Construct Validity
Exploratory factor analysis (EFA) was conducted using maximum likelihood extraction with oblique rotation and Kaiser normalization. Kaiser-Meyer-Olkin (KMO) and Bartlett’s test were performed to assess the partial correlation between factors. Items with inter-item correlation scores greater than 0.8 and communalities scores less than 0.2 were systematically removed. The number of factors retained was determined by examining a scree plot and conducting EFA for various factors.Citation23
Statistical Analysis
Descriptive analyses were performed for the baseline characteristics of the respondents. The current age and age of initiation of ATS were reported using the mean, while the duration of ATS use was reported using the median. Validity and reliability testing were assessed using EFA, ICC, and calculation of the alpha coefficient. Univariate analysis was conducted to determine the association between sociodemographic factors and the scores achieved for each factor.
All statistical analyses were conducted using the International Business Machines (IBM) Statistical Package for Social Sciences (SPSS) version 25.
Results
Sociodemographic Characteristics
All 205 recruited respondents completed the questionnaire for both the first and second tests. The majority of them were Malay (n=198, 96.6%) and male (n=195, 95.1%). The mean age of the respondents was 33.32 years, with ages ranging from 15 to 67 years old. Additionally, 151 respondents (73.7%) had completed secondary education. Only 23 out of the 122 employed respondents (18.85%) earned more than the national median monthly wage of RM2,600.00.Citation24
A breakdown of all the sociodemographic characteristics is presented in .
Table 1 Sociodemographic Characteristics
Table 2 Description of Different Factor Models
Table 3 Exploratory Factor Analysis Summary of the Three-Factor Model
Table 4 Finalized Amphetamine-Type Stimulant Craving Questionnaire (English) with Factor Structure and Reliability Scores
Table 5 Univariate Analysis of Sociodemographic Factors
Face and Content Validation
Six bilingual subject matter experts were recruited to review the content and language usage of the questionnaire. The average item content validation index (S-CVI/Ave) was calculated to be 0.92, which exceeds the recommended value of 0.83. This indicates that, from a content perspective, the items in this questionnaire are deemed relevant for measuring ATS cravings.Citation20 Additionally, the expert panels provided several suggestions for improving the understandability of the questionnaire by enhancing the use of the Malay language.
Construct Validity and Internal Reliability
The KMO test yielded a score of 0.904, indicating sampling adequacy, while Bartlett’s test was significant at p<0.001, indicating that correlations between items were sufficiently large for factor analysis. Following these tests, two items were removed due to low communalities. The scree plot suggested a two-factor model. Subsequently, exploratory factor analysis (EFA) was conducted on two-, three-, and four-factor models, as suggested by Costello & Osborne (2005). The four-factor model was based on the original study by Tiffany et al.Citation8 The factor structure that best satisfied the criteria for a clean structure—item loadings >0.3, item cross-loadings ratio <75%, no factors with less than three items, and at least five strongly loaded items—was selected.Citation23,Citation25
This study found that a three-factor model fits the best as it satisfies all the characteristics stated above. and showcase the results of the factor analysis.
Finalized Questionnaire with Reliability Testing Scores
After conducting the exploratory factor analysis, each factor and its corresponding items were carefully reviewed. Items were then removed to ensure substantive meaning within each factor. This process resulted in a finalized version of the questionnaire consisting of 27 items organized into three factors: (1) Anticipation of positive outcome and relief from withdrawals, (2) Desire to use, and (3) Plan to use and lack of control.
A test-retest was conducted, and all 205 respondents answered both the pre- and post-tests within a one-week period. The questionnaire achieved a Cronbach’s alpha coefficient of more than 0.7 for all factors and a score above 0.75 for the intraclass correlation coefficient (ICC), indicating a reliable scale.Citation26,Citation27 summarizes the finalized questionnaire along with the internal and test-retest reliability scores.
Association Between Respondent’s Sociodemographic Factors with Total Score
Several sociodemographic factors were tested for associations with the factor structure to understand the differences in the effects of these factors on the total score. Current age, age of substance initiation, use of ATS within the past year, and history of previous rehabilitation program admission were found to significantly affect the total score. illustrates the results of the univariate analysis of sociodemographic factors on the factor structure.
The duration of ATS use was also significantly associated with all factors – Factor 1 (ρ=0.288, p-value < 0.001), Factor 2 (ρ=0.275, p-value < 0.001), and Factor 3 (ρ=0.152, p-value < 0.05).
Discussion
The study aimed to adapt, translate, and validate the Cocaine Cravings Questionnaire (CCQ) developed by Tiffany et al (1993) into a Malay Amphetamine-type Stimulant Cravings Questionnaire (ATSCQ-M) for use among the Malaysian population. This study reports the psychometric properties of the ATSCQ-M to measure desire, intention of use, reduction of withdrawal symptoms, and anticipation of a positive outcome from usage.Citation8 The respondents in this study were predominantly men, single, completed secondary education, and were lower-income earners, which were demographically similar to a substance prevalence study done in Malaysia.Citation28 Furthermore, the mean age of the study samples (33.32 years old) was also similar to the average age group of individuals who use ATS locally and globally. Worryingly, more than half (61.5%) initiated ATS use either in their adolescence or youth. Being at the age where one is in school or has just started their career, one would wonder if these stimulants were used for their nootropic effects. Unaware of the potential psychosocial harm it may bring to them, these adolescents and youths may look towards stimulants as a way to improve their cognitive and physical prowess.Citation29
The adaptation, translation, and validation of a questionnaire into another language require careful consideration not just to ensure content validity but also to ensure that the translated version uses language easily understandable by the intended population.Citation30 The face and content validation carried out in this study involved recruiting bilingual subject matter experts with experience in treating people with substance use disorders to ensure that the items retained similar meaning and clarity. Additionally, common street names of ATS, such as “ice”, “pil kuda”, “batu”, and “pil goyang”, were provided to the respondents prior to answering the questionnaire, which may further improve the clarity of the questions asked and reduce errors in measurements.Citation31
This study explored several factor structures with differing numbers of factors based on the scree plot and the original CCQ-Now. A three-factor model was found to fit the population most accurately. This was unlike the original CCQ-Now, which reported four factors.Citation8 This difference could be attributed to the fact that the samples in this study were recruited from those currently undergoing treatment in rehabilitation centers. This was also noted by Tiffany et al (1993), whereby the factor structure may differ depending on the sample’s intervention status. Other translation studies also reported a differing number of factors.Citation8 The Mexican translation of CCQ found a three-factor model, whereas the Italian translation found a five-factor model to fit their population better.Citation32,Citation33 Although all studies differ in their factor structures, all factors are derivative of the original five factors from CCQ, which are (1) Desire to use, (2) Intention and planning to use cocaine, (3) Anticipation of Positive Outcome, (4) Anticipation of relief from withdrawal or dysphoria, and (5) Lack of control over use.
In examining the effects of sociodemographic factors on the three constructs of cravings, this study found, upon univariate analysis, that older individuals and those who initiated substance use at an older age scored higher for “anticipation of positive outcome and relief from withdrawals” and “desire to use” whereas those who had never been admitted into a rehabilitation program scored higher for “planning and lack of control to use.” This contrasts with the findings of Bonfiglio et al (2019), where in their study, younger individuals scored significantly higher for almost all factors.Citation33 This difference could possibly be due to the fact that in our study, the older age groups have been using these substances for a far longer period of time, which may have led to higher scores for both of these factors. Furthermore, cravings in older individuals are less affected by optimism compared to younger individuals.Citation34 Other than that, those who have been admitted to rehabilitation centers before may have been taught ways to cope with their cravings.
Furthermore, it was also found that among those who have used ATS in the past year, they scored significantly higher for “anticipation of positive outcome and relief from withdrawals” and “planning and lack of control to use” than those who had not used. Similar findings were observed in a recent study where those who had used it within the past month were 6.8 times more likely to report having cravings than those who had not used it among treatment-seeking patients for substance use disorder.Citation35 This may be attributed to the fact that those who have remained abstinent for longer periods of time have better control over their emotional symptoms and are better able to cope with their cravings.
A limitation of this study is the relatively low number of respondents, as it was challenging to recruit current active users of ATS. It would have been preferable to have a 10-to-1 respondents-to-item ratio, as suggested by Bujang et al (2022).Citation22 Another limitation is the inability to proceed with criterion validity due to the lack of an already validated Malay questionnaire measuring cravings. Furthermore, face validity among groups of individuals who use substances and experts would have been beneficial for measuring the acceptance of the questionnaire, as their lived experience may guide the formation of more acceptable items. Lastly, the lack of diversity in recruiting women and non-Malays warrants a need for pre-testing among individuals outside of these criteria.
In addition to the suggestions above, it would also be beneficial to investigate the possible use of a shorter version of the questionnaire within the population in a future study. A shorter questionnaire may help reduce respondent fatigue, especially in studies that use more than one type of questionnaire. Other studies have concluded that a brief version of the craving questionnaire is just as reliable in measuring levels of substance cravings as the full-length counterpart.Citation36
Conclusion and Recommendation
The psychometric properties of the ATSCQ-M reported are indicative of a valid and reliable questionnaire that can be used to measure levels of cravings in the local population who use ATS. In addition to using easy-to-read sentences, the questionnaire also provides examples of ATS using common local street names to help study participants understand the items more easily. This questionnaire may serve as an assessment tool that can be used to facilitate the preparation of treatment programs for people with ATS use disorder. Furthermore, as cravings may predict relapse, this tool may also prove beneficial for healthcare providers to gauge the risk of relapse among individuals receiving treatment.
Furthermore, this tool may not be confined to measuring the level of cravings for ATS alone but may also be usable for new psychoactive substances (synthetic stimulants) as they may manifest with similar presentations.Citation37 In view of the rising prevalence of new psychoactive substances, this tool would prove useful for healthcare providers in the treatment of not just individuals who use ATS but also those who use new psychoactive substances (synthetic stimulants).
Author Contributions
All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.
Disclosure
The authors have no competing interests to declare in this work.
Acknowledgments
This study was supported by the Malaysian Ministry of Higher Education (MoHE) under the grant LRGS/1/2019/UKM/02/2/3 and Universiti Kebangsaan Malaysia Medical Centre.
References
- Drummond DC. Theories of drug craving, ancient and modern. Addiction. 2001;96(1):33–46. doi:10.1046/j.1360-0443.2001.961333.x
- Ekhtiari H, Nasseri P, Yavari F, Mokri A, Monterosso J. Neuroscience of drug craving for addiction medicine. Prog Brain Res. 2016;(223):115–141. doi:10.1016/bs.pbr.2015.10.002
- Tiffany ST, Wray JM. The clinical significance of drug craving. Ann N Y Acad Sci. 2012;1248(1):1–17. doi:10.1111/j.1749-6632.2011.06298.x
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders; 2013.
- Shmulewitz D, Stohl M, Greenstein E, et al. Validity of the DSM-5 craving criterion for alcohol, tobacco, cannabis, cocaine, heroin, and non-prescription use of prescription painkillers (opioids). Psychol Med. 2023;53(5):1955–1969. doi:10.1017/S0033291721003652
- Moore TM, Seavey A, Ritter K, McNulty JK, Gordon KC, Stuart GL. Ecological momentary assessment of the effects of craving and affect on risk for relapse during substance abuse treatment. Psychol Addict Behav. 2014;28(2):619–624. doi:10.1037/a0034127
- Yunos N, Ibrahim F, Zakaria E, et al. Relationship between Drug Craving and HighRisk Situations for Relapse Among Inmates with Substance Abuse Issues. Int J Curr Res Rev. 2021;13(18):40–43. doi:10.31782/IJCRR.2021.131819
- Tiffany ST, Singleton E, Haertzen CA, Henningfield JE. The development of a cocaine craving questionnaire. Drug Alcohol Depend. 1993;34(1):19–28. doi:10.1016/0376-8716(93)90042-O
- Vivolo-Kantor AM, Hoots BE, Seth P, Jones CM. Recent trends and associated factors of amphetamine-type stimulant overdoses in emergency departments. Drug Alcohol Depend. 2020;216:108323. doi:10.1016/j.drugalcdep.2020.108323
- United Nations Office on Drugs and Crime (UNODC). World Drug Report 2020. Book 3: Drug Supply; 2020.
- Agensi Antidadah Kebangsaan. Maklumat Dadah 2020; 2020.
- Desrosiers A, Chooi WT, Zaharim NM, et al. Emerging Drug Use Trends in Kelantan, Malaysia. J Psychoactive Drugs. 2016;48(3):218–226. doi:10.1080/02791072.2016.1185553
- Institute for Public Health Malaysia. National Health and Morbidity Survey (NHMS) 2022: Adolescent Health Survey - Key Findings; 2022.
- Wahab S, Baharom MA, Abd Rahman FN, et al. The relationship of lifetime substance-use disorder with family functioning, childhood victimisation, and depression, among juvenile offenders in Malaysia. Addict Behav Rep. 2021:14. doi:10.1016/j.abrep.2021.100359
- Guerin AA, Bridson T, Plapp HM, Bedi G. A systematic review and meta-analysis of health, functional, and cognitive outcomes in young people who use methamphetamine. Neurosci Biobehav Rev. 2023;153:105380. doi:10.1016/j.neubiorev.2023.105380
- Abdul Razak NS, Wahab S, Sidi H, Chemi N, Ahmad N. Predictors of Methamphetamine-Induced Psychosis: a Comparison of Socio-Demographic Factors, Clinical Factors and Psychopathology with Acute Episode Schizophrenia. Int J Acad Res Bus Soc Sci. 2023;13(6):1141–1159. doi:10.6007/IJARBSS/v13-i6/17569
- Zapata LB, Hillis SD, Marchbanks PA, Curtis KM, Lowry R. Methamphetamine use is independently associated with recent risky sexual behaviors and adolescent pregnancy. J Sch Health. 2008;78(12):641–648. doi:10.1111/j.1746-1561.2008.00360.x
- Yusof F, Wahab S. Issues and challenges in the management of methamphetamine dependence in pregnancy. Malays J Med Health Sci. 2015;11(1):89–92.
- Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health-related quality of life measures: literature review and proposed guidelines. J Clin Epidemiol. 1993;46(12):1417–1432. doi:10.1016/0895-4356(93)90142-N
- Yusoff MSB. ABC of Content Validation and Content Validity Index Calculation. Educ Med J. 2019;11(2):49–54. doi:10.21315/eimj2019.11.2.6
- Suhr DD. Exploratory or Confirmatory Factor Analysis? SAS Users Group Int. 2006;31:200–231.
- Bujang MA, Khee HY, Yee LK. A Step-By-Step Guide to Questionnaire Validation Research. Institute for Clinical Research, NIH MY; 2022.
- Costello AB, Osborne J. Best practices in exploratory factor analysis: four recommendations for getting the most from your analysis. Pract Assess Res Eval. 2005;10. doi:10.7275/JYJ1-4868
- Department of Statistics Malaysia. Formal Sector Wages; 2023. Available from: https://open.dosm.gov.my. Accessed March 21, 2024.
- Samuels P. Advice on Exploratory Factor Analysis. 2017.
- McDowell I. Measuring Health. Oxford University Press; 2006; doi:10.1093/acprof:oso/9780195165678.001.0001
- Tavakol M, Dennick R. Making sense of Cronbach’s alpha. Int J Med Educ. 2011;2:53–55. doi:10.5116/ijme.4dfb.8dfd
- Ismail R, Abdul Manaf MR, Hassan MR, et al. Prevalence of Drug and Substance Use among Malaysian Youth: a Nationwide Survey. Int J Environ Res Public Health. 2022;19(8):4684. doi:10.3390/ijerph19084684
- Urban KR, Gao WJ. Psychostimulants As Cognitive Enhancers in Adolescents: more Risk than Reward? Front Public Health. 2017;5:260. doi:10.3389/fpubh.2017.00260
- Sousa VD, Rojjanasrirat W. Translation, adaptation and validation of instruments or scales for use in cross-cultural health care research: a clear and user-friendly guideline. J Eval Clin Pract. 2011;17(2):268–274. doi:10.1111/j.1365-2753.2010.01434.x
- Johnson TP. Sources of Error in Substance Use Prevalence Surveys. Int Sch Res Not. 2014;2014:1–21. doi:10.1155/2014/923290
- Marín-Navarrete R, Mejía-Cruz D, Templos-Nuñez L, et al. Validation of a cocaine craving questionnaire (CCQ-G) in Mexican population. Salud Ment. 2011;34(6):491–496.
- Bonfiglio NS, Renati R, Agus M, Penna MP. Validation of a substance craving questionnaire (SCQ) in Italian population. Addict Behav Rep. 2019;9:100172. doi:10.1016/j.abrep.2019.100172
- Hochheimer M, Strickland JC, Ellis JD, et al. Age moderates the association of optimism on craving during substance use disorder treatment. J Subst Use Addict Treat. 2024;160:209297. doi:10.1016/j.josat.2024.209297
- Cless MM, Courchesne-Krak NS, Bhatt KV, Mittal ML, Marienfeld CB. Craving among patients seeking treatment for substance use disorder. Discov Ment Health. 2023;3(1):23. doi:10.1007/s44192-023-00049-y
- Sussner BD, Smelson DA, Rodrigues S, Kline A, Losonczy M, Ziedonis D. The validity and reliability of a brief measure of cocaine craving. Drug Alcohol Depend. 2006;83(3):233–237. doi:10.1016/j.drugalcdep.2005.11.022
- Rinaldi R, Bersani G, Marinelli E, Zaami S. The rise of new psychoactive substances and psychiatric implications: a wide‐ranging, multifaceted challenge that needs far‐reaching common legislative strategies. Hum Psychopharmacol Clin Exp. 2020;35(3):e2727. doi:10.1002/hup.2727