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In This Issue of JAMA Psychiatry
November 2018


JAMA Psychiatry. 2018;75(11):1097. doi:10.1001/jamapsychiatry.2017.3007


Cannabidiol has antipsychotic effects, but its brain actions are not well understood. Bhattacharyya and colleagues conducted a double-blind, placebo-controlled randomized clinical trial and found that clinical high risk (CHR) participants receiving placebo showed reduced right caudate, parahippocampal gyrus, and midbrain activation compared with healthy participants, whereas CHR participants receiving cannabidiol showed partial normalization of these abnormalities. Thus, cannabidiol positively affects brain circuitry critical to the emergence of psychosis in the CHR state.

Residential mobility may be a risk factor for psychosis. Using a cohort of more than 1.4 million people born in Sweden over 14 years, Price and colleagues studied residential mobility and psychosis and found that more frequent moves during childhood and adolescence were associated with greater risk; moving greater distances before age 16 years was also associated with elevated risk of psychosis. This study indicates children and adolescents with less disruption in their residential environments were less likely to experience psychotic disorders in early adulthood.

Schizophrenia and bipolar disorder are characterized by clinical and biological heterogeneity. Using structural magnetic resonance imaging data, Wolfers and colleagues showed that deviations from the normative model in brain structure were frequent in both disorders but highly heterogeneous, with only a small number of brain loci showing the same abnormalities in patients with the same disorder. These findings suggest that group-level differences disguise biological heterogeneity, which is substantial. In an Editorial, Tamminga and Ivleva discuss implications for our understanding of psychotic disorders.


Functional impairments are significant in psychosis and depression, but little is known about risk stratification in their early phases. Using machine learning approaches to structural magnetic resonance imaging data and longitudinal follow-up in 236 patients, Koutsouleris and colleagues showed that addition of neuroimaging provided significant improvement in prognostic certainty in both clinical high risk for psychosis and recent-onset depression groups. These risk-stratification tools may improve individualized prediction for individuals in early phases of psychosis and depression. In an Editorial, Voineskos discusses implications for the field.


Kendler and colleagues used an instrumental variable approach with a Swedish population-based registry to examine the association between academic achievement and drug abuse. Using month of birth as an instrumental variable, they found no association with risk for drug abuse. However, lower academic achievement had a strong association with risk for subsequent drug abuse registration. These findings suggest that an association observed between academic achievement at age 16 years and risk of drug abuse into middle adulthood may be causal.