Guller et alArticle used concurrent transcranial magnetic stimulation and functional magnetic resonance imaging to test a model of abnormal thalamic functioning in schizophrenia. The results confirmed that transcranial magnetic stimulation of the precentral gyrus of individuals with schizophrenia produced a reduced response in the thalamus, as well as in the superior frontal gyrus and insula. This was associated with reduced functional connectivity between the thalamus and superior frontal gyrus and insula.
Using methods for measuring structural and functional connectivity, Zhang et alArticle identified convergent evidence of altered frontolimbic connectivity in generalized anxiety disorder (GAD). Patients with GAD demonstrated lower microstructural integrity of the uncinate fasciculus. Individual differences in structural connectivity were correlated with functional coupling of the pregenual anterior cingulate and amygdala during the anticipation of aversion.
Sexton et alArticle report an in vivo comparison between elderly patients with a history of depression and matched healthy volunteers. Patients showed significant reduction in brain white matter integrity, without significant group differences in gray matter volumes or functional connectivity. This apparent high diagnostic sensitivity of diffusion tensor images, in the absence of functional changes, may be due to the role of structural connectivity deficits in the vulnerability of elderly individuals to developing depressive episodes.
In a large-scale adoption study of drug abuse (DA), Kendler et alArticle show that adoptee DA was predicted by DA in biological parents and siblings and adoptive siblings and by divorce/death in adoptive parents. Adverse environmental effects were more pathogenic in individuals at high genetic risk for DA.
Wolf et alArticle examined the relationship between dissociation and posttraumatic stress disorder (PTSD) using latent profile analysis. Results provided support for a small but discrete dissociative subtype of PTSD, which was defined by symptoms of derealization, depersonalization, and flashbacks and associated with greater frequency of childhood and adult sexual abuse. The subtype accounted for 6% of the trauma-exposed sample and 12% of those with current PTSD.
El Marroun et alArticle examined the effects of maternal use of selective serotonin reuptake inhibitors during pregnancy on fetal growth and birth outcomes in a prospective population-based cohort. They report that untreated maternal depression during pregnancy was associated with slower fetal body and head growth. The pregnant women treated with selective serotonin reuptake inhibitors had fewer depressive symptoms; their offspring had no delay in body growth but did have a markedly delayed head growth.
In a population-based cohort study investigating the effects of maternal use of antipsychotics on gestational diabetes and fetal growth, Bodén et alArticle identified 507 users of antipsychotics and compared them with nonusers during pregnancy. Users of antipsychotics had a 2-fold increased risk of gestational diabetes. Olanzapine and clozapine exposure increased the risks of macrocephaly.
Labonté et alArticle investigated the epigenetic consequences of childhood maltreatment on the hippocampus using a genome-wide approach. Their findings reveal that early-life adversity induces reprogramming of DNA methylation patterns in specific gene promoters and in genes involved in neuronal plasticity. Their work suggests that childhood adversity modifies DNA methylation patterns differently in neurons compared with other nonneuronal cell types.
Agrawal et alArticle demonstrate that carriers of the minor allele of rs1049353 in the gene encoding the human cannabinoid receptor 1 (CNR1) are buffered from the pathogenic effect of childhood physical abuse on anhedonia and anhedonic depression. This gene × environment interplay was identified in a cohort of young women from a twin population in the United States and independently replicated in a sample of heroin-dependent cases and controls from Australia.
Using functional magnetic resonance imaging, Harrison et alArticle examined the brain response of patients with obsessive-compulsive disorder during a difficult moral decision-making task. Compared with healthy participants, patients showed significantly greater activation of the medial orbitofrontal cortex and left dorsolateral prefrontal cortex. Their findings may represent a link between neurobiological processes and certain maladaptive cognitions in this disorder.
Edden et alArticle investigated cortical inhibition in ADHD, applying edited magnetic resonance spectroscopy to measure the concentration of the inhibitory neurotransmitter GABA in a sensorimotor region of children with ADHD and typically developing controls aged 8 to 12 years. They show that a diagnosis of ADHD is associated with significantly reduced GABA concentration.
This Month in Archives of General Psychiatry. Arch Gen Psychiatry. 2012;69(7):656. doi:10.1001/archgenpsychiatry.2011.1214