Differences in regional cerebral blood flow response to a 5HT3 antagonist in early- and late-onset cocaine-dependent subjects.

5-hydroxytryptamine 3 (5HT3) receptors are important modulators of mesostriatal dopaminergic transmission and have been implicated in the pathophysiology of cocaine reward, withdrawal and self-administration. In addition, the 5HT3 antagonist ondansetron is effective in treating early-onset, but not late-onset, alcohol-dependent subjects. To explore the role of 5HT3 receptor systems in cocaine addiction using functioning imaging, we administered ondansetron to 23 abstinent, treatment-seeking cocaine-addicted and 22 sex-, age- and race-matched healthy control participants. Differences between early- (first use before 20 years, n = 10) and late-onset (first use after 20 years, n = 10) cocaine-addicted subjects were also assessed. On two separate days, subjects were administered ondansetron (0.15 mg/kg intravenously over 15 minutes) or saline. Regional cerebral blood flow (rCBF) was measured following each infusion with single photon emission computed tomography. No significant rCBF differences between the cocaine-addicted and control participants were observed following ondansetron relative to saline. Early-onset subjects, however, showed increased (P < 0.001) right posterior parahippocampal rCBF following ondansetron. In contrast, late-onset subjects showed decreased rCBF following ondansetron in an overlapping region of the right parahippocampal/hippocampal gyrus. Early-onset subjects also displayed increased rCBF in the left anterior insula and subthalamic nucleus following ondansetron; late-onset subjects showed decreased rCBF in the right anterior insula. These findings suggest that the age of drug use onset is associated with serotonergic biosignatures in cocaine-addicted subjects. Further clarification of these alterations may guide targeted treatment with serotonergic medications similar to those successfully used in alcohol-dependent patients.

Altered neural cholinergic receptor systems in cocaine-addicted subjects.

Changes in the brain's cholinergic receptor systems underlie several neuropsychiatric disorders, including Alzheimer's disease, schizophrenia, and depression. An emerging preclinical literature also reveals that acetylcoholine may have an important function in addictive processes, including reward, learning, and memory. This study was designed to assess alterations in cholinergic receptor systems in limbic regions of abstinent cocaine-addicted subjects compared with healthy controls. On three separate days, 23 1- to 6-week abstinent, cocaine- (and mostly nicotine-) addicted subjects and 22 sex-, age-, and race-matched control subjects were administered the muscarinic and nicotinic cholinergic agonist physostigmine, the muscarinic antagonist scopolamine, and saline. Regional cerebral blood flow (rCBF) after each infusion was determined using single photon emission-computed tomography. Both cholinergic probes induced rCBF changes (p<0.005) in relatively distinct, cholinergic-rich, limbic brain regions. After physostigmine, cocaine-addicted subjects showed altered rCBF, relative to controls, in limbic regions, including the left hippocampus, left amygdala, and right insula. Group differences in the right dorsolateral prefrontal cortex, posterior cingulate, and middle temporal gyrus were also evident. Scopolamine also revealed group differences in the left hippocampus and right insula as well as the posterior cingulate and middle temporal gyrus. Cocaine addicted and controls differ in their subcortical, limbic, and cortical response to cholinergic probes in areas relevant to craving, learning, and memory. Cholinergic systems may offer a pharmacologic target for cocaine addiction treatment.

Do atypical antipsychotics effectively treat co-occurring bipolar disorder and stimulant dependence? A randomized, double-blind trial.

OBJECTIVES: The primary objective was to compare the efficacy and tolerability of quetiapine and risperidone in the treatment of mood symptoms, drug cravings, and drug use in outpatients with concurrent DSM-IV-defined bipolar I or II disorder and cocaine or methamphetamine dependence. METHOD: Men and women of all ethnic origins, 20 to 50 years of age, were eligible to participate. Persons were excluded if they were inpatients, met DSM-IV criteria for substance-induced mood disorder, had any other substance dependence, were euthymic or suicidal, had any life-threatening illnesses, or were currently receiving antipsychotic medications. Duration of the trial was 20 weeks. Study participants attended weekly visits and were evaluated for mood symptoms, drug cravings, drug use, and medication side effects. Treatment outcomes were analyzed using linear mixed models. Fixed-effects terms for medication group, study week, and group-by-study-week were included in the models. The study was conducted between October 2002 and November 2006. RESULTS: Of 124 consenting outpatients, an evaluable sample of 80 patients who attended baseline and at least 1 follow-up study visit was formed. The mean +/- SD exit dose for quetiapine was 303.6 +/- 151.9 mg/day and 3.1 +/- 1.2 mg/day for risperidone. Both quetiapine (N = 42) and risperidone (N = 38) significantly improved manic and depressive symptoms and reduced drug cravings (p < .0005) compared to baseline. Decreased drug cravings were related to less frequent drug use (p = .03). The 2 medications did not significantly differ in their effects on mood symptoms, drug craving, or drug use. CONCLUSIONS: Relative to baseline mood and drug-craving status, both quetiapine and risperidone were associated with manic, mixed, and depressive symptom improvement and reduced drug cravings. Both medications were well tolerated. The interpretation of these results is limited by the absence of a placebo control. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00227123.

Depression in Asthma: Prevalence and Clinical Implications.

BACKGROUND: Asthma and depression are both common illnesses. Data suggest that the prevalence of asthma and asthma-related morbidity and mortality has increased in the past 2 decades. Asthma has long been considered an illness in which mood and emotions contribute to symptom exacerbation. Therefore, we reviewed the recent literature on depression in persons with asthma. DATA SOURCES: The MEDLINE (1966-1999) and PSYCHINFO (1967-1999) databases were used to find English-language articles on asthma and depression. Search terms included asthma, depression, dysthymia, and mood. DATA SYNTHESIS: This literature suggests depressive symptoms are more common in asthma patients than in the general population and perhaps even more common than in some other general medical conditions. Depression may be associated with asthma morbidity and mortality. Limited data suggest the older tricyclic antidepressants may improve both depression and asthma symptoms. However, no studies have examined the use of second-generation antidepressants in asthma patients. CONCLUSION: Depressive symptoms are common in asthma patients. However, the prevalence of depressive disorders in this population is not well determined. Future studies should focus on determining the prevalence of major depressive disorder in this population and the effect of antidepressants on mood and asthma symptoms.