Developmental changes in stress adaptation in relation to psychopathology

Neurological soft signs predict abnormal cerebellar-thalamic tract development and negative symptoms in adolescents at high risk for psychosis: a longitudinal perspective

INTRODUCTION

There is an emerging consensus that neurological soft signs (NSS) may not be "soft" at all but rather may reflect neuropathy, particularly in the cerebellum and thalamus. However, our understanding of connective tract abnormalities is limited, and to date, there have been no investigations examining NSS and longitudinal white matter development during the prodrome. Mapping the correlates of NSS in ultrahigh-risk (UHR) youth offers potential for highlighting a viable biomarker as well as for advancing understanding of pathogenic processes during the adolescent risk period.

METHODS

A total of 68 (33 UHR and 35 healthy control) adolescents were assessed with an NSS inventory, structured interviews, and diffusion tensor imaging. Fractional anisotropy (FA) of theoretically relevant cerebellar-thalamic tracts was calculated (left/right superior cerebellar peduncles [SCPs]). Twelve months later, a subset of 30 (15 UHR and 15 control) participants returned for follow-up diffusion tension imaging/clinical assessments.

RESULTS

UHR youth exhibited elevated NSS across domains. While there were no group differences in the integrity of the SCPs at baseline, controls showed a normative increase while the UHR group showed a decrease in FA over 12 months. NSS predicted a longitudinal decrease in cerebellar-thalamic FA and elevations in negative but not positive symptoms 12 months later.

DISCUSSION

Findings of abnormal white matter development provide direct empirical evidence to support prominent neurodevelopmental theories. The predictive relationships between NSS and longitudinal cerebellar-thalamic tract integrity and negative symptom course provide insight into the role of cognitive dysmetria in the high-risk period and inform on a unique biomarker tied to core features underlying psychosis.

Early environmental predictors of the affective and interpersonal constructs of psychopathy

Early childhood maltreatment (i.e., physical, sexual, emotional abuse) and caregiver disruptions are hypothesized to be instrumental in altering the neurobiology of the brain, particularly the amygdala, and contributing to the development of the affective deficits examined in individuals with psychopathy. Exposure to early untoward life events in models of rodent and nonhuman primates changes the neurobiology of the stress response. It is hypothesized that these changes may permanently shape brain regions that mediate stress and emotion and therefore play a role in the etiology of affective disorders in humans. The significance of experience (e.g., the intensity/severity, chronicity/duration, and developmental timing of experiences) and how the accompanying changes in the activity of the hypothalamic-pituitary-adrenocortical system affect alterations in the amygdala are discussed as critical contributors to the etiology of psychopathy. A model is proposed in which early maltreatment experiences contribute to alterations to the amygdala and produce a blunted or dissociative response to stress, a key factor in the affective deficits observed in psychopaths.

The experience-dependent maturation of a regulatory system in the orbital prefrontal cortex and the origin of developmental psychopathology

The maturation of corticolimbic systems that neurobiologically mediate essential affective and social regulatory functions is experience dependent. During the first and second years of life, the infant's affective experiences, especially those embedded in the relationship with the primary caregiver, elicit patterns of psychobiological alterations that influence the activity of subcortically produced trophic bioamines, peptides, and steroids that regulate the critical period growth and organization of the developing neocortex. Interactive attachment experiences of psychobiological attunemcnt, stressful misattunement, and stress-regulating repair and reattunement that maximize positive and minimize negative affect are imprinted into the orbitofrontal cortex — the hierarchical apex of the limbic system that is expanded in the early developing right hemisphere. During the critical period of maturation of thissystem, prolonged episodes of intense and unregulated interactive stress are manifest in disorganizing experiences of heightened negative affect and altered levels of stress hormones, and this chaotic biochemical alteration of the internal environment triggers an extensive apoptotic panellation of corticolimbic circuitries. In this manner less than optimal affect-regulating experiences with the primary caregiver are imprinted into the circuits of this frontolimbic system that is instrumental to attachment functions, thereby producing orbitofrontal organizations that neurobiologically express different patterns of insecure attachments. Such pathomorphogenetic outcomes result in structurally defective systems that, under stress, inefficiently regulate subcortical mechanisms that mediate the physiological processes that underlie emotion. The functional impairments of the cortical-subcortical circuitries of this prefrontal system are implicated in an enduring vulnerability to and the pathophysiology of various later forming psychiatric disorders.

The social zeitgeber theory, circadian rhythms, and mood disorders: review and evaluation

The social zeitgeber theory [Ehlers, C. L., Frank, E., & Kupfer, D. J. (1988). Social zeitgebers and biological rhythms. Archives of General Psychiatry, 45, 948-952] offers an explanation of how life events trigger depressive episodes. According to this theory, life stress leads to mood episodes by causing disruptions in individuals' social routines and, in turn, their biological circadian rhythms. In this article, we review the literature pertaining to the social zeitgeber theory, as well as evidence that this theory may be applied to (hypo)manic episodes. Given the limited data supporting the social zeitgeber theory to date, we also evaluate whether circadian rhythm disruptions are triggered by an internal mechanism, such as an abnormality in one's pacemaker (the suprachiasmatic nucleus; SCN). We review these two theories in an attempt to understand the potential causes of circadian rhythm disruptions and affective episodes in individuals with unipolar and bipolar disorders. We also propose several areas of future research.

A developmental psychopathology perspective on adolescence

Developmental psychopathology offers an integrative framework for conceptualizing the course of development during adolescence, with particular relevance for understanding continuity and the emergence of psychopathology during this and subsequent developmental periods. In this article, the utility of a developmental psychopathology perspective for informing the design of research, prevention, and intervention is highlighted. Interdisciplinary, organizational models of development, emphasizing the dynamic relations between the developing individual and internal and external contexts, are discussed. Examination of boundaries between abnormal and normal development during adolescence offers important vantage points for articulating diversity in the developmental course during this period. Conceptualizing divergence and convergence in developmental pathways, continuity and discontinuity in development, and the transactions of risk and protective processes leading to maladaptation, psychopathology, and resilience are highlighted.

The role of the Child Health Services in promoting mental health: an introduction

This paper gives an introduction to the psychosocial work in the Swedish Child Health Services (CHS). There are substantial problems in defining and evaluating the preventive mental health work of the CHS. The issues raised include: why early preventive intervention is important; the promotion of parental mental health as an aim of the CHS; how the CHS can increase parenting knowledge and skills; what evidence there is about intervention among target groups; and finally, how recent research knowledge can be applied in the CHS.

Developmental neuropathology and the precursors of schizophrenia

Changes in the manifestation of vulnerability to schizophrenia across the lifespan may hold important clues about aetiology. They may also illustrate some general principles about the nature of neurodevelopmental processes. Within the framework of a neural diathesis-stress model, we review findings on the precursors of schizophrenia and schizotypal personality disorder. The findings suggest that there are critical developmental periods for the manifestation of dysfunction and that, within certain domains of behaviour, there is a temporal disjunction between the onset of the neuropathology and its expression. It also appears that the diathesis for schizophrenia involves polymorphic behavioural expression, such that it can be manifested in multiple domains - motoric, cognitive and socio-emotional. Taken together, the data on the longitudinal course of schizophrenia indicate that the expression of the diathesis is moderated by central nervous system maturational processes. One putative moderating system, the hypothalamic-pituitary-adrenal (HPA) axis, is discussed, and implications for preventive intervention are explored.