Pratique d'une intervention motivationnelle pour les consommateurs de cannabis souffrant de psychose

Abstract

Background: The use of cannabis among people suffering from psychosis is common and doubles the risk of relapse, aggravates positive symptoms and decreases the level of social functioning. Access to care remains difficult for these patients. Psychotic symptoms themselves could either be a powerful motivation to change behaviour when patients link traumatic psychotic events with cannabis use, or represent a cognitive and symptomatic obstacle to the treatment. Principles of treatment of dual diagnosis disorders have been described, mainly for cocaine and opiate users. However, cannabis among persons with psychosis is generally perceived as trivial and inoffensive, although particularly harmful for these subjects. Treatment strategies must therefore be adapted to these specificities. Acceptable and effective interventions must be developed on the basis of the following principles: (a) simultaneously treating psychosis and consumption of cannabis, (b) taking account of cognitive deficits associated with schizophrenia and (c) adapting the motivational interviewing to these cognitive deficits. The first four sessions of our intervention include: (1) the creation of an alliance and evaluation consumption, (2) the resolution of the ambivalence about the consumption of motivational techniques and (3) the adaptation of goals according to the stage of change. Objectives: The purpose of this article is to describe and illustrate a clinical scenario, stages of a motivational intervention aimed at consumers of cannabis with psychotic symptoms. Method: The intervention has been developed and performed on 30 subjects as part of a controlled study. The first four sessions are: (1) the establishment of a therapeutic alliance and the evaluation of consumption, (2) resolution of the ambivalence about cannabis use by motivational techniques, (3) adaptation of goals according to the stage of change. The description of the intervention was based on an anonymised clinical vignette. Results: The population covered by the study is predominantly male (87%) with a diagnosis of schizophrenia (60%) and with a dependence on cannabis (87%). The intervention is well accepted by the subjects, who are maintained at 80% in the treatment after one year. The initial assessment of consumption makes it possible to evaluate the extent of the problem and can be accompanied by the user's awareness about the links between psychotic symptoms and cannabis use. The motivational approach allows the therapist to get an empathetic understanding of the patient's reasons for cannabis use and to explore possible alternatives. The patient may also share ambivalent aspects without fearing retaliation.The goals of treatment are then set according to the current stage of motivation. Thus, this method is also applicable to persons without perception of the problem and no desire for change. Conclusion: The intervention is well accepted and allows access and maintenance to treatment for psychotic patients with problematic cannabis use. Preliminary data available do not yet permit the analysis of results in terms of reducing cannabis, positive changes in symptoms or use of acute psychiatric services.