Experience of social discrimination correlates with neurometabolism: a pilot study in heroin addicts.

Experimental social neuroscience has shown that being socially excluded is processed in the anterior cingulate cortex (ACC). We hypothesize that a chronic form of social exclusion resembling one aspect of social stigmatization is associated with altered neural plasticity reflected by neurometabolic alterations in the ACC. To test this hypothesis, a highly stigmatized patient group of heroin addicts (N = 15) during opiate maintenance therapy rated a questionnaire about being stigmatized, and neurometabolic markers in the ACC were determined using (1)H MR spectroscopy. We found a negative correlation between discrimination experience and N-acetylaspartate (NAA), indicating attenuated neuron functioning in the anterior cingulate cortex in those patients reporting high discrimination experience. Furthermore, perceived stigmatization showed an association with anxiety that was mediated by NAA. Although the correlative analysis cannot give evidence for a causal relationship, the relation of NAA in the ACC and discrimination experience indicates a malfunction of the neural system involved in cognitive control over emotionally relevant social stimuli in discrimination reporting heroin addicts. Further research is needed to elucidate factors associated with chronic stigmatization.

MR spectroscopy in opiate maintenance therapy: association of glutamate with the number of previous withdrawals in the anterior cingulate cortex.

Pre-clinical research indicates that opioids reduce extracellular glutamate in acute opioid treatment, whereas during withdrawal, glutamatergic neurotransmission is increased and withdrawal symptoms can be blocked by glutamate receptor antagonists. The glutamate hypothesis of addiction suggests that withdrawal-associated hyperglutamatergic states destabilize the glutamatergic system chronically and contribute to relapse. magnetic resonance spectroscopy at three tesla optimized for glutamate assessment (TE 80 ms) was performed in the anterior cingulate gyrus (ACC) and frontal white matter (fWM) of 17 opiate-dependent patients during opiate maintenance therapy and 20 healthy controls. Controlling for age and gray matter content, glutamate in the ACC was positively associated with the number of previous withdrawals. For glutamate + glutamine (Glx), a significant group-age interaction was found. Whereas Glx declines with age in healthy controls, Glx increases with age in opiate-dependent patients. The number of previous withdrawals did not correlate with age. In fWM spectra, increased Cho concentrations were observed in opiate-dependent patients. Both new findings, the positive correlation of glutamate and previous withdrawals and increasing Glx with age in contrast to an age-dependent Glx decrease in controls indicate a destabilization of the glutamate system in opiate-dependent patients and support the glutamate hypothesis of addiction. Increased Cho concentrations in fWM corroborate findings of WM abnormalities in opioid-dependent subjects.

Impaired decision making in opiate addiction correlates with anxiety and self-directedness but not substance use parameters.

BACKGROUND: Despite a large number of empirical reports of impaired decision making in substance use disorders, the underlying factors contributing to such deficits remain to be elucidated. This study examined the potential influences of personality traits, affective symptoms, and pharmacological variables on decision making, as measured by the Iowa Gambling Task (IGT) in a sample of opioid-dependent patients. METHODS: A total of 46 opioid-dependent patients taking part in an opiate maintenance outpatient program and 46 healthy control subjects performed the IGT. Personality traits and affective symptoms were examined by using Zuckerman Sensation-Seeking Scale, the State-Trait Anxiety Inventory and Beck Depression Inventory. In addition, Cloninger Temperament and Character Inventory was administered in the patient group. Information on current and life-time substance use was acquired with a standardized interview. RESULTS: Opioid-dependent patients performed significantly worse on the IGT than controls. This difference disappeared after statistically controlling for trait anxiety, state anxiety, disinhibition, depressive symptoms, and lifetime alcohol consumption. Trait and state anxiety and self-directedness were significantly associated with the IGT final score. Hierarchical regression analyses suggested that self-directedness differentially moderated the relationships between the anxiety variables and IGT performance. CONCLUSIONS: The decision-making impairments observed in opioid-dependent patients are influenced by current levels of anxiety and the personality markers trait anxiety and self-directedness. Differences in decision making between opioid-dependent and healthy individuals may also be due to differences in other personality facets, affective symptoms, and alcohol consumption. Amount of opioid and other substance intake did not show any effects. These results indicate that psychological characteristics may have a higher impact on decision-making performance than drug-induced pharmacological effects.

The vicious circle of perceived stigmatization, depressiveness, anxiety, and low quality of life in substituted heroin addicts.

BACKGROUND: Perceived stigmatization of drug addicts may interact with negative mood states and thus may contribute to the maintenance of addictive behavior. METHODS: Opiate maintenance patients (n = 106) and an unselected comparison group (n = 144) rated self-report questionnaires about perceived stigmatization, quality of life (QoL), depressiveness, anxiety, self-esteem, addiction characteristics, and social support. RESULTS: 63% of opiate maintenance patients felt discriminated in contrast to 16% of the comparison group. Perceived stigmatization was rated higher by opiate maintenance patients, and all domains of QoL were rated lower, even when statistically controlling depressiveness, anxiety and social factors. Perceived stigmatization was correlated to depressiveness, anxiety, low self-esteem and low QoL, but not addiction characteristics and social support. Structural equation models revealed anxiety and the pathway depressiveness enhancing feelings of being stigmatized resulting in low self-esteem to explain 74% of variance in mental QoL, whereas anxiety and a pathway stigmatization inducing depressiveness leading to low self-esteem explained 49% of variance in physical QoL. CONCLUSIONS: A vicious circle of stigmatization, negative affective states and low QoL was confirmed. In addition to societal antistigma campaigns, antidepressive and anxiolytic therapy might have the potential to diminish feelings of being stigmatized and to improve QoL.