Perinatal factors have previously been linked to aggression and criminal violence. In this article, Brennan et al (SEE ARTICLE) found a relationship between maternal prenatal smoking and criminal arrest in a large sample of Danish men. Maternal smoking was related to overall criminal arrests, arrests for violence, and a pattern of offending that persists from adolescence into adulthood. A commentary by Fergusson (SEE ARTICLE) is included.
Analyzing data obtained from a large population sample of twins, Silberg et al (SEE ARTICLE) report a significant increase in the influence of genetic factors on depression in pubertal girls. The genes effecting risk to depression were also found to increase risk for the occurrence of stressful life events. The "switching on" of genes for depression during puberty and their influence on negative life events may be one explanation for the increased rate of depression in girls and its continuation through adolescence.
Several studies have shown that obstetric complications may increase the risk of schizophrenia, although the underlying mechanisms are unknown. Dalman et al (SEE ARTICLE) have attempted to assess specific risk factors, such as fetal malnutrition, extreme prematurity, and hypoxia or ischemia during birth and the incidence of schizophrenia in a cohort of 507,516 persons identified in the Swedish Medical Birth Register. They confirmed increased risk of schizophrenia associated with several perinatal risk factors, although preeclampsia was the strongest one.
Relapse prevention is a major clinical challenge in the treatment of patients with schizophrenia or schizoaffective disorder. In a large group of patients followed up for 5 years from their first episode of illness, Robinson et al (SEE ARTICLE) found that more than 80% have 1 psychotic relapse; rates for a second and third relapse were similarly large. Withdrawal of antipsychotics increased the relapse risk by almost 5 times; poor premorbid functioning also increased relapse risk. These results argue strongly for maintenance medication for first-episode patients.
During the last few years particular attention has been paid to defining the role of cyclic adenosine monophosphate (cAMP) signal transductin pathway in affective disorders. Perez et al (SEE ARTICLE) , using immunoblotting techniques to quantitate cAMP-dependent protein kinase subunits and Rap1, one of its substrates, found that the levels of these proteins are altered in blood platelets from untreated euthymic, depressed, and manic bipolar patients.
Strakowski et al (SEE ARTICLE) examined differences between patients with bipolar disorder and healthy volunteers in the volumes of a network of brain structures thought to modulate emotion. The bipolar patients demonstrated a significant difference from healthy subjects in this neural network in general, and, in particular, they demonstrated enlargement of the amygdala and possibly the thalamus and globus pallidus.
Depression and dementia (including Alzheimer disease) frequently coexist, but their cause and effect relationship is unclear and probably complex. In this epidemiological study, Chen et al (SEE ARTICLE) examined a large community population over time and found that depressive symptoms were likely to follow rather than precede the onset of symptoms of dementia. Thus, depressive symptoms seemed to be early manifestations rather than predictors of dementia.
Evidence suggests that schizophrenia involves dysfunction of left temporal lobe regions specialized for language processing. In a psychophysiologic study, Bruder et al (SEE ARTICLE) report that schizophrenic patients did not show the normal left-brain superiority for phonetic processing. Also, brain potentials associated with cognitive processing were most reduced over left temporal lobe sites. These findings are of importance for understanding neurophysiologic abnormalties that may contribute to language-related symptoms.
Schizophrenia is characterized by an inability to screen or "gate" trivial stimuli, theoretically leading to stimulus overload and thought disturbance. Past studies have correlated gating and thought disturbance measures recorded at different times, and assumed that the association represented a concurrent relationship. Perry et al (SEE ARTICLE) developed a paradigm in which gating and thought disturbance were measured at essentially the same time and found a very strong relationship between these 2 hallmarks of schizophrenia. It was concluded that gating disturbances may share a common neurobiological substrate with thought disturbance.
