Reasoning deficits among illicit drug users are associated with aspects of cannabis use

Background. Deficits in deductive reasoning have been observed among ecstasy/polydrug users. The present study seeks to investigate dose-related effects of specific drugs and whether these vary with the cognitive demands of the task. Methods. One hundred and five participants (mean age 21.33, S.D. 3.14; 77 females, 28 males) attempted to generate solutions for eight one-model syllogisms and one syllogism for which there was no valid conclusion (NVC). All of the one model syllogisms generated at least one valid conclusion and six generated two valid conclusions. In these six cases one of the conclusions was classified as common and the other as non-common. Results. The number of valid common inferences was negatively associated with aspects of short term cannabis use and with measures of IQ. The outcomes observed were more than simple post intoxication effects since cannabis use in the 10 days immediately before testing was unrelated to reasoning performance. Following adjustment for multiple comparisons, the number of non-common valid inferences was not significantly associated with any of the drug use measures. Conclusions. Recent cannabis use appears to impair the processes associated with generating valid common inferences while not affecting the production of non-common inferences. It is possible, therefore, that the two types of inference may recruit different executive resources which may differ in their susceptibility to cannabis-related effects

3,4-Methylenedioxymethamphetamine (MDMA) neurotoxicity in rats: a reappraisal of past and present findings

RATIONALE: 3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused illicit drug. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been interpreted as neurotoxicity. Whether such 5-HT deficits reflect neuronal damage is a matter of ongoing debate. OBJECTIVE: The present paper reviews four specific issues related to the hypothesis of MDMA neurotoxicity in rats: (1) the effects of MDMA on monoamine neurons, (2) the use of “interspecies scaling” to adjust MDMA doses across species, (3) the effects of MDMA on established markers of neuronal damage, and (4) functional impairments associated with MDMA-induced 5-HT depletions. RESULTS: MDMA is a substrate for monoamine transporters, and stimulated release of 5-HT, NE, and DA mediates effects of the drug. MDMA produces neurochemical, endocrine, and behavioral actions in rats and humans at equivalent doses (e.g., 1–2 mg/kg), suggesting that there is no reason to adjust doses between these species. Typical doses of MDMA causing long-term 5-HT depletions in rats (e.g., 10–20 mg/kg) do not reliably increase markers of neurotoxic damage such as cell death, silver staining, or reactive gliosis. MDMA-induced 5-HT depletions are accompanied by a number of functional consequences including reductions in evoked 5-HT release and changes in hormone secretion. Perhaps more importantly, administration of MDMA to rats induces persistent anxiety-like behaviors in the absence of measurable 5-HT deficits. CONCLUSIONS: MDMA-induced 5-HT depletions are not necessarily synonymous with neurotoxic damage. However, doses of MDMA which do not cause long-term 5-HT depletions can have protracted effects on behavior, suggesting even moderate doses of the drug may pose risks

Oral health sensations associated with illicit drug abuse

Objectives: To investigate oral health sensations (short term oral health effects) associated with illicit drug abuse. In addition, to identify variations in oral health sensations produced by different illicit drugs. Subject: Young adults in a drug rehabilitation programme in Hong Kong, China. Method: Self-completed questionnaire about their previous pattern of drug abuse and oral health sensations experienced (recalled). Results: All (119) subjects were poly-drug abusers (abused one or more illicit drugs in the past). Amphetamine-based drugs such as methamphetamine ('speed') and methylenedioxymethamphetine ('ecstasy') were commonly abused. A wide range of oral health sensations were reported on recall of their abuse of illicit drugs; most frequently dry mouth (95%, 113). Types of illicit drugs abused were associated with oral health sensations reported (P < 0.001). 'Ecstasy' abusers more frequently reported chewing (P < 0.001), grinding (P < 0.001), and TMJ tenderness (P < 0.001) compared to non-'ecstasy' abusers. Conclusion: Illicit drug abuse produces many oral health sensations. Types of drugs abused were associated with oral sensations produced, and behavioural effects that may manifest as depression, anxiety, memory loss and various neuropsychotic disorders.8,9 In some cases drug abuse can result in death by various means: malignant hyperthermia, internal bleeding, fatal overdosing and through allergic reactions.10,11 Likewise, there have been reports on the long term clinical effects of illicit drug abused on oral health, © British Dental Journal 2005.link_to_subscribed_fulltex