Possible Interaction: Marijuana and Methylphenidate

“Group comparisons revealed that in CUD compared to controls, metabolism in nucleus accumbens was lower for the placebo and MPH measures, that MPH-induced increases in thalamic metabolism were blunted, and that enhanced negative connectivity between thalamus and accumbens in CUD was normalized by MPH (reducing negative connectivity).”

“ MPH ’s normalization of thalamo-accumbens connectivity (reduced negative connectivity) brings forth its potential therapeutic value in CUD , which merits investigation.”

“We hypothesized that MPH would increase thalamic connectivity and metabolism, and that this response would be blunted in cannabis abusers.”

“The attenuated responses to MP in midbrain and striatum are consistent with decreased brain reactivity to dopamine stimulation and might contribute to addictive behaviors in CA.”

“Illicit users often coadminister MPH with marijuana.”

“Although baseline (placebo) measures of striatal DA D2 receptor availability did not differ between groups, the marijuana abusers showed markedly blunted responses when challenged with MP.”

“Specifically, compared … controls, marijuana abusers had significantly attenuated behavioral (“self-reports” for high, drug effects, anxiety, and restlessness), cardiovascular (pulse rate and diastolic blood pressure), and brain DA [reduced decreases in distribution volumes (DVs) of [11C]raclopride, although normal reductions in striatal nondisplaceable binding potential (BPND)] responses to MP.”

“We found that marijuana abusers display attenuated dopamine (DA) responses to MP , including reduced decreases in striatal distribution volumes.”

“Moreover, is it possible that methylphenidate and marijuana have additive effect and caused the symptoms?”

“A significant association (p < 0.001) was found between MPH use and the frequency of using alcohol, tobacco, cannabis , hard drugs (e.g. cocaine) and prescription medication.”