Alcohol and Alcoholism Advance Access originally published online on April 24, 2006
Alcohol and Alcoholism 2006 41(4):421-425; doi:10.1093/alcalc/agl035
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ALCOHOL CRAVING IN PROBLEM AND OCCASIONAL ALCOHOL DRINKERS
Institute for Medical Psychology, Centre for Humanities and Health Sciences, Charité Universitätsmedizin Berlin, Germany and Department of Clinical and Cognitive Neuroscience at the University of Heidelberg, Central Institute of Mental Health, Mannheim, Germany
* Author to whom correspondence should be addressed: Tel: +49 30 450 529 521; Fax: +49 30 450 529 923; E-mail: sabine.gruesser{at}charite.de
(Received 18 August 2005; first review notified 6 October 2005; in revised form 24 February 2006; accepted 10 March 2006)
| ABSTRACT |
|---|
|
|
|---|
Aims: The impact of emotional states on alcohol craving has so far mainly been investigated in abstinent and actively consuming alcohol addicts. Alcohol craving and the variables that influence alcohol craving have not yet been examined in non-addicted, alcohol abusing drinkers and non-abusing occasional alcohol drinkers. Methods: In this study 50 problem drinkers and 50 occasional alcohol drinkers were investigated. The impact of various craving-related variables such as stress and distress, alcohol effect expectancies, and stress coping strategies on reward and relief craving was examined and compared between the groups. Results: Whereas most occasional drinkers reported little alcohol craving, problem drinkers showed a significantly higher amount of reward and relief craving accompanied by increased levels of stressdistress and a stronger tendency to use negative (inadequate) coping strategies. Stress-distress and alcohol effect expectancies were significant predictors of reward and relief craving in problem drinkers. In occasional drinkers alcohol craving was not related to any of these variables. These variables were also found to be predictive of craving in alcohol addicts. Conclusions: We hypothesized, that in non-addicted problem drinkers the expected rewarding and reinforcing alcohol effects lead to an early stage of addictive behaviour. Therefore, in this stage therapeutic interventions focussing on the awareness of the function of alcohol intake as well as alternative coping skills might be useful to prevent alcohol dependence in problem drinkers.
| INTRODUCTION |
|---|
|
|
|---|
Craving for psychotropic substances has been discussed as a variable of central importance for the maintenance of addiction (Kozlowski and Wilkinson, 1987
Alcohol abuse and alcohol addiction impair a wide range of emotional, motivational, and cognitive processes (Tyssen et al., 1998
; Volpicelli et al., 1999
; Monti et al., 2000
). Stress and negative affect, either as a situation-specific condition (e.g. negative mood) or as a general affective state (e.g. depression, anxiety), may be important in the development and mediation of alcohol craving (Sinha, 2001
; Goeders, 2003
; Zywiak et al., 2003
; Birch et al., 2004
). Negative affective and motivational states as well as stressors can act as learned (conditioned) alcohol-related cues and trigger alcohol craving and, consequently, can themselves contribute on the development and maintenance of addictive behaviour (McCusker and Brown, 1991
; Greeley et al., 1992
; Hodgins et al., 1995
; Cooney et al., 1997
; Sinha, 2001
). Furthermore, Marlatt and Gordon (1985)
suggested that cognitive factors such as expectancies or beliefs can induce craving and relapse and he also emphasized that craving and self efficacy are reciprocally related (see also Kallmen et al., 2003
; May et al., 2003
; Walton et al., 2003
).
Conditioning and memory processes have been discussed as underlying mechanisms of the interaction between emotional, cognitive, and motivational factors, and craving as well as alcohol intake (O'Brien et al., 1992
; Everitt et al., 2001
; Cardinal et al., 2002
). According to the model of classical conditioning, originally unconditioned internal (e.g. mood states) and external neutral stimuli (e.g. wine bottle) can become alcohol-associated and can elicit an emotionalmotivational state that may lead to craving and motivate renewed drug intake (Robinson and Berridge, 1993
, 2003
; Berridge and Robinson, 1998
; Grüsser et al., 2000
). These conditioned responses to alcohol-associated cues were described in addicts even after a long period of abstinence (Wikler, 1965
; O'Brien et al., 1992
). After drinking alcohol, operant conditioning processes based on positive (e.g. improved mood, relaxation) or negative reinforcing (e.g. reduction of withdrawal symptoms, stress, pain, and anxiety) effects of alcohol lead to the maintenance of the addictive behavioural pattern.
However, emotional states, cognitive factors, and their association with craving have predominantly been investigated in clinical groups compared with healthy controls. Less attention has been paid to the impact of cognitive factors and affective states on alcohol craving in persons who drink regularly but are not yet addicted. Thus, the present study examined alcohol craving and drinking patterns in non-addicted persons with regular or occasional alcohol consumption. From a prevention point of view this might be an interesting group to study. In addition, variables related to stress, emotional states, and alcohol consumption were determined as possible psychological predictors of relief and reward craving for alcohol.
| METHODS |
|---|
|
|
|---|
Participants
Two equally sized samples (N = 50) comprising 100 alcohol-consuming subjects with different drinking patterns participated in the study. Information regarding participants' drinking patterns and alcohol-related disorders were assessed with the structured clinical interview for DSM-IV (SCID-I, Wittchen et al., 1997
Instruments and procedure
Alcohol drinking patterns were determined using the questionnaire of differentiated assessment of addiction (QDAA, Grüsser et al., 2004
). Furthermore, the QDAA was applied to assess sociodemographic and clinical data as well as alcohol craving and addiction-related variables such as alcohol effect expectancies, current mood, and the experienced severity of distress and somatic complaints. The two dimensions of general craving: reward craving (e.g. anticipation of a positive outcome) and relief craving (e.g. avoidance or relief of withdrawal symptoms and negative affective states) were assessed by visual analogue scales (VAS, 0100 mm, ranging from not at all to very strong; see Grüsser et al., 2000
). Alcohol effect expectancies were assessed by 11 adjectives describing main effects of alcohol (e.g. relaxing, stimulating, euphorigenic). All items are rated by visual analogue scales (VAS, 0100 mm, ranging from not at all expected to very strong expected). Two total mean scores can be computed describing the strength of positive (e.g. euphorigenic, performance-enhancing) and negative alcohol expectancies (e.g. conflict-enhancing, injuring health). Current mood was measured by the summed total score of nine items describing different states of mood (e.g. sad, happy, stressed, low spirited), which are rated on 010 Likert-type scales. A high total score indicates a positive state of mood. A 03 Likert-type rating scale was used for the 23-item scale assessing the severity of distress and somatic complaints (e.g. lack of drive, nervousness, anxiety, headache, hot and cold flushes, arrhythmia) in the last week. The QDAA is a valid and reliable instrument for the assessment of addiction, patterns of drug consumption, and addiction-related variables. The subscales show good internal consistency ranging from 0.82 (mood scale) to 0.92 (distress and somatic complaints) and adequate correlations with similar instruments (r > 0.40; Grüsser et al., 2004
).
The trait scale of the German version of the state-trait-anxiety-inventory (STAI, Laux et al., 1981
) is a widely used 20-item measure of anxiety. The German version of the center for epidemiological studies depression scale (CES-D, Hautzinger and Bailer, 1993
) is a screening instrument to separate subgroups with a high probability of having a depressive episode and determines the level of depressive symptoms. The scale is based on 20 items rated on a four-step Likert-type scale and the resulting composite CES-D score ranges from 0 to 60.
Participants' general tendency to use positive (e.g. relaxation, positive self instruction) or negative (e.g. flight, resignation) strategies was assessed by the stress coping questionnaire (SVF 120, Janke and Erdmann, 1996
). The SVF consists of 20 subscales of six items each that assess specific coping strategies (e.g. avoidance, drug use, positive self-instruction, flight, resignation). Each subscale item is rated on a four-step Likert-type scale concerning the tendency to use a specific strategy to cope with stressful situations. The 20 subscales are aggregated to two higher order scales assessing the tendency to use positive and negative coping strategies. The total score of each higher order scale ranges from 0 to 24. The SVF is a widely used instrument to assess coping strategies in German speaking countries. The subscales and the higher order scales of the SVF showed good internal consistency (r = 0.630.92; r = 0.820.96; Janke and Erdmann, 1996
).
Statistical analysis
All statistical analyses were carried out using SPSS version 11.01. Group differences concerning categorical sociodemographic data were analysed using
2-tests while continuous data were analysed using t-tests for independent samples. A principal component analysis was conducted to extract one factor labelled as stress-distress of the highly intercorrelated affective and stress-related variables such as depression (ADS), anxiety (STAI), current mood (QDAA) as well as distress and stress related to somatic complaints (QDAA). All affective variables loaded higher than 0.46 on the common factor. Standardized factor scores estimated by regression were transformed into T-scores (mean (M) = 50.00; SD = 10.00).
To investigate the effect of group membership on reward and relief craving as well as on further addiction-related variables a multivariate analyses of variance (MANOVA) with group as a between-subjects factor was conducted. To test for influences of affective and cognitive variables on the intensity of reward and relief craving for alcohol stepwise multiple regression analyses were used including expectancies of positive and negative alcohol effects, stress-distress, and positive as well as negative effect expectancies as independent affective and cognitive variables. Significant predictors of drug craving were compared between the both samples. For easier reading of the result section, results failing to reach statistical significance as well as P-values of pair-wise comparisons in case of one-way analyses of variance are not shown if they did not differ from the significance level of the one-way analyses of variance itself.
| RESULTS |
|---|
|
|
|---|
Sociodemographic data and alcohol-related characteristics
PD (M = 38.48, SD = 9.93) and OD (M = 39.97, SD = 8.21) did not differ significantly in mean age. Gender (PD: 80.0% male; OD: 74.4% male; P = 0.48), secondary education (PD: 30.0%; OD: 25.6%; P = 0.60), and percentage of unemployed persons (PD: 48.0%; OD: 46.2%; P = 0.99) were equally distributed among both samples. Both groups did not differ significantly in the age (in years) when they drank alcohol for the first time (PD: M = 14.48, SD = 3.22; OD: M = 14.74, SD = 2.20). PD consumed a significantly higher amount of alcohol (M = 336.64, SD = 26.77 g of alcohol, 4.00 standard drinks per day) during the previous week than OD (M = 18.59, SD = 19.72 g of alcohol, 0.22 standard drinks per day; t(87) = 62.16; P < 0.001).
Group differences
PD reported significantly higher reward (F(1,92) = 32.16; P < 0.001) as well as relief craving for alcohol (F(1,92) = 25.58; P < 0.001) than OD. PD and OD did not differ in their expectation of positive (F(1,92) = 0.22; P = 0.64) or negative (F(1,92) = 1.32; P = 0.25) alcohol effects. Furthermore, they did not differ in their amount of positive coping strategies (F(1,92) = 0.01; P = 0.92). However, compared with OD, PD experienced significantly more stressdistress (F(1,92) = 10.19; P < 0.01) and showed a significantly higher amount of negative coping strategies (F(1,92) = 8.59; P < 0.01; for mean scores and standard deviations see Table 1).
|
Impact factors on reward and relief craving for alcohol
Table 2 shows the predictors of reward and relief craving for alcohol. In PD, 29% of the variance of reward craving could be explained by expectancies of positive alcohol effects, stressdistress, and expectancies of negative alcohol effects (F(1,42) = 13.67; P < 0.001). Furthermore, expectancies of positive alcohol effects and stress-distress explained
30% of the variance of relief craving in PD (F(3,45) = 6.02 p < .01). In the OD group, none of the investigated variables reached significance for inclusion in the regression equation of reward or relief craving.
|
| DISCUSSION |
|---|
|
|
|---|
The aim of the present study was to examine the impact of various psychological variables such as stressdistress, coping strategies, and alcohol effect expectancies on reward and relief alcohol craving in non-addicted problem alcohol drinkers and occasional alcohol drinkers. Several studies showed that psychological variables such as emotional states are highly associated with alcohol addiction (Niaura et al., 1988
In the present study high alcohol consumption during the previous week was accompanied by a higher level of reward and relief craving in problem alcohol drinkers, whereas most occasional drinkers reported little alcohol craving. Data obtained from the validation study of the QDAA showed that alcohol dependent subjects reported a quite similar and only a slightly higher amount of reward (M = 42.70; SD = 22.28) and relief craving for alcohol (M = 41.63; SD = 19.94; see Grüsser et al., 2004
). Although the sample was not compared in the same study these data suggest that craving as a typical characteristic of alcohol dependence and as a criterion of substance dependence according to the ICD-10 can occur in non-dependent subjects (Field et al., 2005
). Furthermore, problem alcohol drinkers showed higher levels of stressdistress and more negative coping strategies compared with occasional alcohol drinkers, whereas no significant groups differences were detectable for positive coping strategies or alcohol effect expectancies. However, only stress-distress but not negative coping strategies predicted craving thus suggesting that stimulus-oriented rather than response-oriented variables are better predictors.
In addition to stressdistress alcohol effect expectancies are powerful predictors of reward as well as relief craving in problem alcohol drinkers, whereas in occasional alcohol drinkers levels of craving were not influenced by these variables. This could be a true effect of the low level drinking habits or be related to the low level of craving in this group leading to limited variance that could induce floor effects. The level of experienced stressdistress seems to be an important determinant of craving. This is in accordance with previous studies, which found that stress-accompanying negative affective states increased the expected rewarding effects of drug intake (Piazza and Le Moal, 1998
; Sinha, 2001
; Goeders, 2003
). In problem alcohol drinkers negative alcohol effect expectancies seem to reduce the rewarding alcohol effect since they were significantly related to lower reward craving. Furthermore, higher levels of positive alcohol effect expectancies were associated with increased anticipation of the negative and positive reinforcing effects of alcohol. Whereas occasional alcohol drinkers showed alcohol craving that was not affected by any of the assessed variables, problem alcohol drinkers showed many similarities with alcohol addicts with respect to the variables (stress-distress and alcohol effect expectancies) that affect craving as described in the literature on alcohol addiction (Niaura et al., 1988
; Sinha, 2001
; Stewart, 2003
). In line with the self-medication hypothesis, the problem drinkers could have more frequently used alcohol to reduce their negative affect and, therefore, have had more chances to negatively reinforce the link between alcohol use and negative affect. Thus, the probability for them to consume alcohol again would be enhanced if they experience negative effect (Tiffany, 2000
).
The reciprocal relationship of craving and expectancies of negative (aversive) alcohol effects suggests that imprints warning against negative consequences of alcohol consumption on products containing alcohol might be a promising approach in preventing alcoholism. Furthermore, persons with psychological disorders (e.g. depression, anxiety) experience greater craving and might also be excessively prone to develop alcohol dependence. According to the assumption that learning processes such as operant conditioning can be viewed as underlying mechanisms of the occurrence of craving and alcohol intake, the present study showed that alcohol intake may function as an immediately effective, albeit, maladaptive coping strategy to reduce the experience of stress even in non-addicted, alcohol abusing subjects. In the course of addiction the consumption of psychotropic substances may receive special emphasis as a short-term effective but long-term maladaptive reinforcement, also due to addiction-associated neuroadaptive processes in the mesolimbic reward system (O'Brien et al., 1992
; Everitt et al., 2001
; Cardinal et al., 2002
). Based on the social cognitive model of relapse by Marlatt and Gordon (1985)
coping competencies and the confidence of abstinence are powerful predictors of long-time abstinence in addicts (see also Monti et al., 2000
). In the present study the presence of negative coping strategies or the lack of positive coping strategies was not predictive for alcohol craving in problem alcohol drinkers although they had a higher level. One possible explanation for this could be that problem drinkers who use alcohol intake to cope with stressful situations still have a sufficient repertoire of positive coping strategies. A lack of positive coping strategies may become more important in later stages of addiction owing to the ongoing operant conditioning processes that reinforces the link between stress reduction and alcohol intake. This may lead to a reduced experience in dealing adequately with stressful situations. Finally, with respect to this restricted repertoire of coping strategies, alcohol use may become the most efficient and practised strategy to cope with stress.
It has to be taken into consideration that the number of subjects investigated in the current study was relatively low and that these analyses are correlational and do not give any indication about causal mechanisms. This study specifically focused on craving characteristics in non-dependent subjects. In this study differences between craving in dependent and non-dependent alcohol drinkers could not be evaluated, but might be necessary to understand craving and its functions with respect to the development of alcohol dependence. Moreover, craving as a multidimensional construct includes emotional, motivational, cognitive, and physiological components. Owing to the self-rating measurement of relief and reward craving predominantly conscious cognitive aspects of craving were covered. Further studies on the relationship between craving, negative affective states, the positive and negative rewarding aspects of alcohol, and alcohol consuming behaviour in problem alcohol drinkers are necessary to investigate the mechanisms of the development of alcohol addiction. From the point of view of prevention of dependence, the reduction of stress and distress in problem drinkers, e.g. by enhancing coping with stress and distress as well as a focus on the negative effects of alcohol might be promising.
| REFERENCES |
|---|
|
|
|---|
American Psychiatric Association (2000) Diagnostic and Statistical Manual of Mental Disorders: DSM-IV-TR. 4th edn, text revision. American Psychiatric Association. Washington, DC.
Berridge, K. C. and Robinson, T. E. (1998) What is the role of dopamine in reward: hedonic impact, reward learning, or incentive salience? Brain Research. Brain Research Reviews 28, 309369.[CrossRef][Medline]
Birch, C. D., Stewart, S. H., Wall, A. M. et al. (2004) Mood-induced increases in alcohol expectancy strength in internally motivated drinkers. Psychology of Addictive Behaviors 18, 231238.
Cardinal, R. N., Parkinson, J. A., Hall, J. et al. (2002) Emotion and motivation: the role of the amygdala, ventral striatum, and prefrontal cortex. Neuroscience and Biobehavioral Reviews 26, 321352.[CrossRef][ISI][Medline]
Cooney, N. L., Litt, M. D., Morse, P. A. et al. (1997) Alcohol cue reactivity, negative-mood reactivity, and relapse in treated alcoholic men. Journal of Abnormal Psychology 106, 243250.[CrossRef][ISI][Medline]
Drobes, D. J. and Thomas, S. E. (1999) Assessing craving for alcohol. Alcohol research and health: The Journal of the National Institute on Alcohol Abuse and Alcoholism 23, 179186.
Everitt, B. J., Dickinson, A. and Robbins, T. W. (2001) The neuropsychological basis of addictive behavior. Brain research. Brain Research Reviews 36, 129138.[CrossRef][Medline]
Field, M., Mogg, K. and Bradley, B. P. (2005) Craving and cognitive biases for alcohol cues in social drinkers. Alcohol and Alcoholism 40, 504510.
Flannery, B. A., Roberts, A. J., Cooney, N. et al. (2001) The role of craving in alcohol use, dependence and treatment. Alcoholism, Clinical and Experimental Research 25, 299308[Medline]
Goeders, N. E. (2003) The impact of stress on addiction. European Neuropsychopharmacology 13, 435441.[CrossRef][ISI][Medline]
Greeley, J. D., Swift, W. and Heather, N. (1992) Depressed affect as a predictor of increased desire for alcohol in current drinkers of alcohol. British Journal of Addiction 87, 10051012.[Medline]
Grüsser, S. M., Heinz, A. and Flor, H. (2000) Standardized stimuli to assess drug craving and drug memory in addicts. Journal of Neural Transmission 107, 715720.[Medline]
Grüsser, S.M., Wölfling, K., Düffert, S. et al. (2004) Psychometrische Kennwerte und erste Ergebnisse zur Validität des Fragebogens zur Differenzierten Drogenanamnese (FDDA). [Psychometric properties and initial validation of the Questionnaire on Differentiated Assessment of Addiction]. Psychotherapie Psychosomatik Medizinische Psychologie 54, 18.
Hautzinger, M. and Bailer, M. (1993) Allgemeine Depressions-Skala ADS-L. [Center for Epidemiological Studies Depression Scale CES-D, German version.] Beltz, Weinheim.
Hodgins, D. C., El-Guebaly, N. and Armstrong, S. (1995) Prospective and retrospective reports of mood states before relapse to substance used. Journal of Consulting and Clinical Psychology 63, 400407.[CrossRef][Medline]
Janke, W. and Erdmann, G. (1996) Stressverarbeitungsfragebogen (SVF 120). Kurzbeschreibung und grundlegende Kennwerte. [Stress Coping Questionnaire. Short description and basic properties.] Hogrefe, Göttingen.
Kallmen, H., Sjoberg, L. and Wennberg, P. (2003) The effect of coping skills training on alcohol consumption in heavy social drinking. Substance Use and Misuse 38, 895903.[CrossRef]
Kozlowski, L. T. and Wilkinson, T. A. (1987) Use and misuse of the concept of craving by alcohol, tobacco, and drug researchers. British Journal of Addiction 82, 3136.[CrossRef][ISI][Medline]
Laux, L., Glanzmann, P., Schaffner, P. et al. (1981) State-Trait-Angst-Inventar STAI. [State-Trait-Anxiety-Inventory STAI, German version.] Beltz, Weinheim.
May, J., Andrade, J., Panabokke, N. et al. (2003) Images of desire: cognitive models of craving. Memory 12, 447461.[CrossRef]
Marlatt, G. A. and Gordon, J. R. (1985) Relapse Prevention, Guilford Press, New York.
McCusker, C. G. and Brown, K. (1991) The cue-responsivity phenomenon in dependent drinkers: personality vulnerability and anxiety as intervening variables. British Journal of Addiction 86, 905912.[CrossRef][ISI][Medline]
Monti, P. M., Rohsenow, D. J. and Hutchison, K. E. (2000) Toward bridging the gap between biological, psychobiological and psychosocial models of alcohol craving. Addiction 95(Suppl. 2), S229S236.
Niaura, R. S., Rohsenow, D. J., Binkoff, J. A. et al. (1988) Relevance of cue reactivity to understanding alcohol and smoking relapse. Journal of Abnormal Psychology 97, 133152.[CrossRef][ISI][Medline]
O'Brien, C. P., Childress, A. R., McLellan, A. T. et al. (1992) A learning model of addiction. In Addictive States, O'Brien, C. P., Jaffe, J. eds, pp. 157177. Ravens Press Ltd., New York.
Piazza, P. V. and Le Moal, M. (1998) The role of stress in drug self-administration. Trends in Pharmacological Sciences 19, 6774.[CrossRef][Medline]
Robinson, T. E. and Berridge, K.C. (1993) The neutral basis of drug craving: an incentive-sensitization theory of addiction. Brain research, Brain research reviews 18, 247281.[CrossRef][Medline]
Robinson, T. E. and Berridge, K. C. (2003) Addiction. Annual Review of Psychology 54, 2553.[CrossRef][ISI][Medline]
Sayette, M. A., Shiffman, S., Tiffany, S. T., Niaura, R. S., Martin, C. S. and Shadel, W. G. (2000) The measurement of drug craving. Addiction 95(Suppl. 2), S189S210.
Sinha, R. (2001) How does stress increase risk of drug abuse and relapse? Psychopharmacology 158, 343359.[CrossRef][Medline]
Stewart, J. (2000) Pathways to relapse: the neurobiology of drug and stress-induced relapse to drug-taking. Journal of Psychiatry and Neuroscience 25, 125136.[ISI][Medline]
Stewart, J. (2003) Stress and relapse to drug seeking: studies in laboratory animals sheet light on mechanisms and sources of long-term vulnerability. The American Journal on Addiction 12, 117.
Tiffany, S. T. (2000) Evaluating relationships between craving and drug use. Addiction 95, 11061107.[Medline]
Tiffany, S. T. and Drobes, D. J. (1991) The development and initial validation of a questionnaire on smoking urges. British Journal of Addiction 86, 14671476.[CrossRef][ISI][Medline]
Tiffany, S. T., Carter, B. L. and Singleton, E. G. (2000) Challenges in the manipulation, assessment and interpretation of craving relevant variables. Addiction 95(Suppl. 2),S177S187.[CrossRef]
Tyssen, R., Vaglum, P., Aasland, O. G., Gronvold, N. T. and Ekeberg, O. (1998) Use of alcohol to cope with tension, and its relation to gender, years in medical school and hazardous drinking: a study of two nation-wide Norwegian samples of medical students. Addiction 93, 13411349.[CrossRef][ISI][Medline]
Verheul, R., Van den Bring, W. and Geerlings, P. (1999). A three-pathway psychobiological model of craving for alcohol. Alcohol and Alcoholism 34, 197222.
Volpicelli, J., Balaraman, G., Hahn, J. et al. (1999) The role of uncontrollable trauma in the development of PTSD and alcohol addiction. Alcohol Research and Health 23, 256262.[ISI][Medline]
Walton, M. A., Blow, F. C., Bingham, C. R. et al. (2003) Individual and social/environmental predictors of alcohol and drug use 2 years following substance abuse treatment. Addictive Behaviors 28, 627642.[CrossRef][ISI][Medline]
Weiss, F., Ciccocioppo, R., Parsons, L. H. et al. (2001) Compulsive drug-seeking behaviour and relapse. Neuroadaptation, stress and conditioning factors. Annals of the New York Academy of Sciences 937, 126.
Wikler A. (1965) Conditioning factors in opiate addiction and relapse. In Narcotics, Willner, D. I. and Kassenbaum, G. G. eds, pp. 721. McGraw-Hill, New York.
Wittchen, H.-U., Wunderlich, U., Gruschwitz, S. et al. (1997) Strukturiertes Klinisches Interview für DSM-IV, Achse-I (SKID). [Structured Clinical Interview for DSM-IV, axis I]. Hogrefe, Göttingen.
Zywiak, W. H., Westerberg, V. S., Connors, G. J. et al. (2003) Exploratory findings from the reasons for drinking questionnaire. Journal of Substance Abuse Treatment 25, 287292.[Medline]
![]()
CiteULike
Connotea
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||