Identifying brain alterations that contribute to suicidal thoughts and behaviors (STBs) are important to develop more targeted and effective strategies to prevent suicide. In the last decade, and especially in the last 5 years, there has been exponential growth in the number of neuroimaging studies reporting structural and functional brain circuitry correlates of STBs. Within this narrative review, we conducted a comprehensive review of neuroimaging studies of STBs published to date and summarize the progress achieved on elucidating neurobiological substrates of STBs, with a focus on converging findings across studies. We review neuroimaging evidence across differing mental disorders for structural, functional, and molecular alterations in association with STBs, which converges particularly in regions of brain systems that subserve emotion and impulse regulation including the ventral prefrontal cortex (VPFC) and dorsal PFC (DPFC), insula and their mesial temporal, striatal and posterior connection sites, as well as in the connections between these brain areas. The reviewed literature suggests that impairments in medial and lateral VPFC regions and their connections may be important in the excessive negative and blunted positive internal states that can stimulate suicidal ideation, and that impairments in a DPFC and inferior frontal gyrus (IFG) system may be important in suicide attempt behaviors. A combination of VPFC and DPFC system disturbances may lead to very high risk circumstances in which suicidal ideation is converted to lethal actions via decreased top-down inhibition of behavior and/or maladaptive, inflexible decision-making and planning. The dorsal anterior cingulate cortex and insula may play important roles in switching between these VPFC and DPFC systems, which may contribute to the transition from suicide thoughts to behaviors. Future neuroimaging research of larger sample sizes, including global efforts, longitudinal designs, and careful consideration of developmental stages, and sex and gender, will facilitate more effectively targeted preventions and interventions to reduce loss of life to suicide.

Early life stress (ELS) has been established as a major risk factor for a multitude of psychiatric and medical disorders. ELS is highly prevalent in the general population and constitutes a major public health concern. The current review will focus on the clinical literature that suggests a link between adverse early life experiences and vulnerability for adolescent and adult substance use disorders. It will investigate the characteristics of ELS that appear to increase risk for disorder onset and a more severe disease course, characterized by earlier onset, greater risk of relapse, and treatment resistance. The authors explore how ELS may increase risk for adverse substance use outcomes through long-lasting changes in the HPA axis and development of stress, reward, and executive control brain systems. The review will also discuss potential pathways to substance use disorder following ELS, with a focus on the role of comorbid mood and anxiety disorders and other modifiable traits. Finally, the authors will discuss how the current body of work presents the potential for prevention and intervention strategies to reduce the psychosocial consequences following early life stress and minimize adverse substance use outcomes.