Lack of allelic association between markers at the DRD2 and ANKK1 gene loci with the alcohol-dependence syndrome and criminal activity

Summary: Dopaminergic dysfunction is associated with genetic risk for psychosis, particularly in individuals with 22q11.2 deletion. This study found increased striatal dopamine synthesis capacity in individuals with 22q11.2 deletion compared to healthy controls and individuals with 22q11.2 duplication. Furthermore, dopamine synthesis was positively correlated with the severity of psychosis-risk symptoms.

Summary: The association between reserpine and depression is inconsistent, and there is limited high-quality evidence available. Due to the complex effects of reserpine, a more nuanced understanding of the monoamine hypothesis of depression is needed.

Summary: This study found significantly lower frontal cortical blood flow in FEP patients before antipsychotic treatment. Additionally, the relative-to-global frontal cerebral blood flow measured before antipsychotic treatment may be associated with treatment response.

Summary: The randomised controlled trial examines the effects of reducing and discontinuing antipsychotics on social functioning and continued use in schizophrenia patients. However, methodological issues mentioned in the trial protocol could potentially impact the interpretation of the findings, such as non-blinded outcome measurement, treatment as usual comparator, and possible sample size problems.

Summary: This systematic review examined the effectiveness of interventions in the early course of bipolar disorder (BD). The findings suggested that lithium use was associated with lower recurrence risk compared to other mood stabilizers, and mood stabilizers were associated with better global functioning compared to antipsychotics in the medium term. Psychological interventions, such as family-focused and cognitive-behavioral interventions, were associated with reduced recurrence risk or improved symptomatic outcomes. Pharmacological interventions were more efficacious when utilized in the earlier stages of illness.

Summary: In this study, a fully automated analytical framework for FDOPA PET neuroimaging data was evaluated. The framework showed good reproducibility and sensitivity to demographic and experimental variables. It represents an effective resource for standardized and robust quantification of dopamine synthesis capacity using FDOPA PET data.

Summary: This narrative review examines the evidence for the serotonin hypothesis of depression, proposed over 50 years ago by Alec Coppen, a British Psychiatrist. It discusses the validity of the hypothesis, with a focus on psychopharmacology, molecular imaging, and systems-level neuroscience.

Summary: A recent umbrella review found no consistent evidence linking serotonin to the pathophysiology of depression. However, we argue that this conclusion is overstated due to methodological weaknesses, selective reporting of data, oversimplification, and errors in the interpretation of neuropsychopharmacological findings. We use the examples of tryptophan depletion and serotonergic molecular imaging, the two most relevant research areas, to support our argument.

Summary: Early detection and diagnosis of alcohol-related cognitive impairment (ARCI) is important, but there is a lack of consensus on diagnostic criteria. This systematic scoping review found limited evidence on screening and diagnostic criteria for ARCI. There is also a lack of research on cognitive assessment tools for patients with suspected non-Korsakoff Syndrome forms of ARCI in 'point-of-care' settings.

Summary: The study aimed to measure the effect of antipsychotics on dopamine synthesis and glutamate concentrations in individuals with psychosis. The results showed that antipsychotic treatment did not significantly affect glutamate concentrations or dopamine synthesis capacity, but did alter the relationship between glutamate and dopamine.

Summary: Background: Major depressive disorder (MDD) is a leading cause of global disability. Several lines of evidence implicate the dopamine system in its pathophysiology. However, the magnitude and consistency of the findings are unknown. We address this by systematically reviewing in vivo imaging evidence for dopamine measures in MDD and meta-analysing these where there are sufficient studies. Methods: Studies investigating the dopaminergic system using positron emission tomography or single photon emission computed tomography in MDD and a control group were included. Demographic, clinical and imaging measures were extracted from each study, and meta-analyses and sensitivity analyses were conducted. Results: We identified 43 studies including 662 patients and 801 controls. Meta-analysis of 38 studies showed no difference in mean or mean variability of striatal D-2/3 receptor availability (g = 0.06, p = 0.620), or combined dopamine synthesis and release capacity (g = 0.19, p = 0.309). Dopamine transporter (DAT) availability was lower in the MDD group in studies using DAT selective tracers (g = -0.56, p = 0.006), but not when tracers with an affinity for serotonin transporters were included (g= -0.21, p = 0.420). Subgroup analysis showed greater dopamine release (g = 0.49, p = 0.030), but no difference in dopamine synthesis capacity (g = -0.21, p = 0.434) in the MDD group. Striatal D-1 receptor availability was lower in patients with MDD in two studies. Conclusions: The meta-analysis indicates striatal DAT availability is lower, but D-2/3 receptor availability is not altered in people with MDD compared to healthy controls. There may be greater dopamine release and lower striatal D-1 receptors in MDD, although further studies are warranted. We discuss factors associated with these findings, discrepancies with preclinical literature and implications for future research.

Summary: This study found that discontinuation of antipsychotic medication is associated with an increased risk of relapse in schizophrenia, which is related to receptor occupancy. Although the rate of discontinuation does not appear to affect relapse, gradual discontinuation strategies may facilitate easier reinstatement of antipsychotic medication in case of symptomatic worsening.