RESUMO
Introduction: Addiction is a mental disorder that has many adverse effects on brain health. It alters brain structure and deteriorates brain functionality. Impairment of brain cognition in drug addiction is illustrated in many previous works; however, olfactory perception in addiction and, in particular, its neuronal mechanisms have rarely been studied. Methods: In this experiment, we recruited 20 heroin addicts and 20 normal controls of the same sex, age, handedness, and socioeconomic status and compared their brain function while perceiving non-craving odors during the functional magnetic resonance imaging (fMRI). We intended to define the default olfactory system performance in addicts compared to healthy people. Results: Our study showed an overall larger activation in addicts when processing olfactory stimuli. In particular, and when comparing the two groups, the right anterior cingulate and right superior frontal gyrus had higher activations than normal, whereas the left lingual gyrus and left cerebellum showed stronger activations in the addicts. Conclusion: The result of this study can unveil the missing components in addiction brain circuitry. This information is helpful in better understanding the neural mechanisms of addiction and may be advantageous in designing programs for addiction prevention or clinical treatment. Highlights: Addiction is a mental disorder with cognitive, clinical, and social adverse effects.Drugs affect the functional brain networks by altering the level of neurotransmitters or by over-exciting the brain's reward system.Addiction could be in the form of drug dependency or behaviors. Plain Language Summary: Addiction is a mental disorder that has many adverse effects on brain. It alters brain structure and deteriorates brain functionality. Impairment of brain cognition in many previous works. We intended to define the default olfactory system performance in addicts compared to healthy people. Our study showed an overall larger activation in addicts when processing olfactory stimuli. In particular, and when comparing the two groups, the right anterior cingulate and right superior frontal gyrus had higher activations than normal, whereas the left lingual gyrus and left cerebellum showed stronger activations in the addicts. Addiction could be in the form of drug dependency or behaviors such as gambling or gaming. Addictive disorders is so vast that sometimes an impulse control disorder, such as pathologic gambling, could also be included.
RESUMO
AIM: Methamphetamine-induced psychosis and neuropsychological impairments are common among patients with methamphetamine use disorder. Given some preclinical and clinical studies reporting potential effects of minocycline, a second-generation tetracycline, on correcting manifestations of drug addiction, this study aimed to examine the effectiveness of minocycline in attenuating psychotic symptoms and neuropsychological impairments in chronic methamphetamine users. METHOD: Five men with treatment-resistant methamphetamine use disorder and psychotic symptoms were selected using a convenience sampling method, and they were administered a daily dose of 200-mg minocycline for 8 weeks; within this period, psychiatric and neuropsychological assessments (including memory and executive functions) were carried out at the baseline, week 2, week 4, week 8, and 2-month follow-up. RESULTS: The findings showed that minocycline attenuated both positive (Cohen d = 0.63) and negative (Cohen d = 0.53) methamphetamine-induced psychotic symptoms and also improved patients' neuropsychological functions, particularly their auditory working memory (Cohen d = 0.45). CONCLUSIONS: These results provide promising evidence regarding the positive effects of minocycline as adjunctive pharmacotherapy for patients with methamphetamine use disorder. However, given that this was an open-label study, further research is warranted to draw a firm conclusion about the effectiveness of minocycline for methamphetamine-induced psychosis and neuropsychological deficits.