News di Alcologia

Metanfetamine e alcol rendono psicotici
di Claudia Moschi

Ormai non ci sono più dubbi: esiste uno stretto legame tra l'assunzione di metanfetamine e i sintomi della psicosi. L'unica incertezza dei ricercatori australiani autori della ricerca era sulla base di partenza: chi ricorre alle droghe è già predisposto a problemi psichici oppure questi sorgono solo dopo una prolungata assunzione delle sostanze? Dunque fino a che punto la droga aggrava lo stato di salute mentale del consumatore? La ricerca ha fornito dati interessanti: il 10% del campione osservato aveva sintomi psicotici anche quando non era sotto gli effetti dei cristalli; il 50% di chi invece li aveva assunti aveva manifestato uno o più comportamenti tipici del disturbo psichiatrico. Per di più è stato scoperto che anche l'utilizzo frequente di marijuana e alcol incide sull'insorgenza di atteggiamenti psicotici.

Dose-Related Psychotic Symptoms in Chronic Methamphetamine Users. Evidence From a Prospective Longitudinal Study

Rebecca McKetin, PhD; Dan I. Lubman, PhD, FRANZCP, FAChAM; Amanda L. Baker, PhD; Sharon Dawe, PhD; Robert L. Ali, FAChAM, FFPHM
JAMA Psychiatry. 2013;():1-6. doi:10.1001/jamapsychiatry.2013.283. Text Size: A A A .Published online January 9, 2013

ABSTRACT.
Context. Methamphetamine is associated with psychotic phenomena, but it is not clear to what extent this relationship is due to premorbid psychosis among people who use the drug.

Objective. To determine the change in the probability of psychotic symptoms occurring during periods of methamphetamine use.

Design. Longitudinal prospective cohort study. A fixed-effects analysis of longitudinal panel data, consisting of 4 noncontiguous 1-month observation periods, was used to examine the relationship between changes in methamphetamine use and the risk of experiencing psychotic symptoms within individuals over time.

Setting. Sydney and Brisbane, Australia.

Participants. A total of 278 participants 16 years of age or older who met DSM-IV criteria for methamphetamine dependence on entry to the study but who did not meet DSM-IV criteria for lifetime schizophrenia or mania.

Main Outcome Measures. Clinically significant psychotic symptoms in the past month, defined as a score of 4 or more on any of the Brief Psychiatric Rating Scale items of suspiciousness, hallucinations, or unusual thought content. The number of days of methamphetamine use in the past month was assessed using the Opiate Treatment Index.

Results. There was a 5-fold increase in the likelihood of psychotic symptoms during periods of methamphetamine use relative to periods of no use (odds ratio [OR], 5.3 [95% CI, 3.4-8.3]; P < .001), this increase being strongly dose-dependent (1-15 days of methamphetamine use vs abstinence in the past month: OR, 4.0 [95% CI, 2.5-6.5]; =16 days of methamphetamine use vs abstinence in the past month: OR, 11.2 [95% CI, 5.9-21.1]). Frequent cannabis and/or alcohol use (=16 days of use in the past month) further increased the odds of psychotic symptoms (cannabis: OR, 2.0 [95% CI, 1.1-3.5]; alcohol: OR, 2.1 [95% CI, 1.1-4.2]).

Conclusions. There was a large dose-dependent increase in the occurrence of psychotic symptoms during periods of methamphetamine use among users of the drug.

(Articolo pubblicato dal CUFRAD sul sito www.alcolnews.it)