Schizophrénie et dépendance aux amphétamines

Abstract

Whereas observations of psychotic disorders induced by amphetamines are common, few observations described the impact of chronic amphetamine abuse on schizophrenic patients. We report the case of a schizophrenic patient who presented with amphetamine dependence for several years, without other accompanying addiction. During his adolescence, Mr. X. gradually developed delusional beliefs of persecution and telepathy. He believed that the other pupils and teachers spoke about him in malicious terms. At the age of 23, Mr. X began to consume 60-100 mg/week of amphetamines orally. He consumed amphetamines during 7 years. The delusions, in particular the auditory hallucinations worsened after the use of amphetamines. Subsequently, he married and was declared unfit for national service due to the psychotic disorders. Mr. X received neuroleptic treatment with moderate effects on the psychotic symptoms. Between the age of 24 and 30, the patient presented persecutory, megalomanic and physical transformation beliefs, delusions of being controlled as well as auditory, somatic-tactile and visual hallucinations. At the age of 30, while he had stopped his consumption of amphetamines for 9 months, the patient, overwhelmed with the delusions, murdered his wife. He was sent in jail for 13 months, and subsequently hospitalized for one year in a high security psychiatric department and 7 years in our psychiatric department. The neuroleptic treatment was effective, particularly against the hallucinations. Following stabilisation, the symptomatology of the patient was marked by a disorganization syndrome, including prominent thought disorder, disorganized speech, associative loosening, frequent derailments and negative signs of schizophrenia, in particular affective flattening and blunting of emotional expression. When the patient was 43, a trial discharge was authorized owing to improvement of his condition. The neuroleptic treatment was switched with single-drug olanzapine therapy, 10 mg/day which improved the negative symptoms. Mr. X. resumed part-time professional activities and remarried. The patient fulfilled the DSM IV criteria for schizophrenia and for amphetamine dependence assessed using the Composite International Diagnostic Interview (CIDI). He presented, in particular, withdrawal syndrome when amphetamines were discontinued. The amphetamine consumption was followed by a marked deterioration in the delusions, particularly the hallucinations. Worsening of the positive symptoms in schizophrenic patients by amphetamines has been established in single dose studies, in particular characterized by persecutory delusions and hallucinations. On the other hand, amphetamines tend to transiently and moderately reduce the negative symptoms. Some stu-dies have shown that amphetamine consumption promoted violent acting out in non-schizophrenic subjects. In our observation, the acting out may be not related to the acute effects of these substances, since it occurred 9 months after stated discontinuation of amphetamine consumption. However, the cerebral toxicity and psycho-behavioural disturbances related to amphetamines might be prolonged after withdrawal. In non-schizophrenic patients, the existence of prolonged neurotoxicity of amphetamines and related psycho-behavioral disturbances has been suggested. The prolonged administration of amphetamines to animals produces neuro-axonal degeneration in the striatum, the frontal cortex, the nucleus accumbens and the amygdala. In human, there are some evidence of persistant deteriorations of the serotoninergic and dopaminergic systems in the caudate nucleus, the putamen and the nucleus accumbens following amphetamine consumption. The neurobiological and psycho-behavioural effects of amphetamines may be prolonged following withdrawal in both schizophrenic and non-schizophrenic patients.