The journey to psychosis: an exploration of specific psychological pathways

Childhood adversity and psychosis: a systematic review of bio-psycho-social mediators and moderators

The association between childhood adversity (CA) and psychosis has been extensively investigated in recent years. An increasing body of research has also focused on the mediating or moderating role of biological and psychological mechanisms, as well as other risk factors that might account for the link between CA and psychosis. We conducted a systematic search of the PsychINFO, Embase, Ovid, and Web of Science databases for original articles investigating the role of genetic vulnerabilities, environmental factors, psychological and psychopathological mechanisms in the association between CA and psychosis up to August 2019. We included studies with individuals at different stages of the psychosis continuum, from subclinical psychotic experiences to diagnosed disorders. From the 28 944 records identified, a total of 121 studies were included in this review. Only 26% of the studies identified met the criteria for methodological robustness. Overall, the current evidence suggests that CA may be associated with psychosis largely independently of genetic vulnerabilities. More consistent and robust evidence supports interaction between early and recent adversities, as well as the mediating role of attachment and mood symptoms, which is suggestive of an affective pathway between CA and psychosis across the continuum from subclinical experiences to diagnosable disorder. This review highlighted numerous methodological issues with the existing literature, including selection bias, heterogeneity of measurement instruments utilised, and lack of control for potential confounders. Future research should address these limitations to more accurately estimate mediation and moderation effects on the CA-psychosis association to inform the development of preventive interventions.

Threatening Life Events and Difficulties and Psychotic Disorder

OBJECTIVE

Stressful life events have been implicated in the onset of psychotic disorders, but there are few robust studies. We sought to examine the nature and magnitude of associations between adult life events and difficulties and first-episode psychoses, particularly focusing on contextual characteristics, including threat, intrusiveness, and independence.

METHOD

This study forms part of the Childhood Adversity and Psychosis Study (CAPsy), an epidemiological case-control study in London, United Kingdom. Data on life events and difficulties (problems lasting 4 wk or more) during 1 year prior to onset (cases) or interview (controls) were assessed using the semi-structured Life Events and Difficulties Schedule (LEDS). Data were available on 253 individuals with a first episode of psychosis and 301 population-based controls.

RESULTS

We found strong evidence that odds of exposure to threatening and intrusive events in the 1 year prior to onset were substantially higher among cases compared with controls, independent of age, gender, ethnicity, and social class (ORs > 3). This was consistent across diagnostic categories. We found further evidence that the effect of threatening events and difficulties was cumulative (1 event odds ratio [OR] 2.69 [95% confidence interval (CI) 1.51-4.79]; 2 events OR 4.87 [95% CI 2.34-10.16]; ≥3 events OR 5.27 [95% CI 1.83-15.19]; 1 difficulty OR 3.02 [95% CI 1.79-5.09]; 2 difficulties OR 9.71 [95% CI 4.20-22.40]; ≥3 difficulties OR 12.84 [95% CI 3.18-51.85]).

CONCLUSIONS

Threatening and intrusive life events and difficulties are common in the year pre-onset among individuals with a first episode of psychosis. Such experiences may contribute to the development of psychotic disorders.

Childhood adversities and psychotic symptoms: The potential mediating or moderating role of neurocognition and social cognition

INTRODUCTION

Childhood abuse and neglect are risk factors for psychotic symptoms. Early adversities may contribute to alterations in neuro/social cognition, which in turn is associated with psychosis. This study explored the possible mediating/moderating role of neuro/social cognition between childhood abuse and neglect on the one hand, and psychotic symptoms on the other.

METHOD

The sampling frame was 1.119 patients with a psychotic disorder. Childhood adversity was evaluated with the Dutch version of the Childhood Trauma Questionnaire. Psychotic symptoms were assessed with the Positive and Negative Syndrome Scale. Verbal learning-memory, attention-vigilance, working memory, information processing speed, reasoning-problem solving were evaluated as measures of neurocognition using the Word Learning Task, the Continuous Performance Test, the Wechsler Adult Intelligence Scale 3rd. Mentalization was evaluated as a measure of social cognition using the Hinting Task. Correlation, mediation, moderation, 95% Bias Corrected and accelerated (BCaCI) bootstrapped analyses were performed, considering possible sex differences.

RESULTS

In male psychotic patients, attention and vigilance mediated the association between childhood neglect and negative symptoms (indirect effect: 0.18, BCaCI: 0.03-0.54), disorganization (indirect effect: 0.26, BCaCI: 0.05-0.61), excitement (indirect effect: 0.07, BCaCI: 0.004-0.23); mentalization mediated the association between childhood neglect and negative symptoms (indirect effect: 0.21, BCaCI: 0.02-0.51), excitement (indirect effect: 0.07, BCaCI: 0.01-0.20) disorganization (indirect effect: 0.29, BCaCI: 0.02-0.64); working memory mediated the association between childhood abuse and disorganization (indirect effect: 0.28, BCaCI: 0.05-0.57), excitement (indirect effect: 0.08, BCaCI: 0.01-0.20), emotional distress (indirect effect: 0.10, BCaCI: 0.01-0.27).

DISCUSSION

In psychotic disorder, sex-specific mediation of neurocognition and mentalization may exist in the association between childhood adversity and psychotic symptoms.

Disrupting Sleep: The Effects of Sleep Loss on Psychotic Experiences Tested in an Experimental Study With Mediation Analysis

Our view is that insomnia may be a causal factor in the occurrence of psychotic experiences such as paranoia and hallucinations. However, the causal relationship is not established. The aim of the study was to investigate the causal role of insomnia in psychotic experiences via a sleep restriction manipulation. The study was a within-subjects crossover design that included a planned mediation analysis. Sixty-eight nonclinical volunteers underwent a sleep loss condition (restricted to 4 h sleep for 3 nights) and a control condition (standard sleep) in randomized order in 2 consecutive weeks, with a weekend washout period. Psychotic experiences (paranoia, hallucinations, grandiosity, and cognitive disorganization) and candidate mediating variables (negative affect and related processes, working memory, decision making, and perceptual processing) were assessed before and after each condition. Actigraphy verified an average sleep duration of 5 h 15 min in the sleep loss condition, vs 6 h 58 min in the control condition. After the sleep loss condition, relative to the control condition, participants reported significant increases in paranoia, hallucinations, and cognitive disorganization, with no significant changes in grandiosity. The sleep loss condition was also associated with significant increases in negative affect, negative self and other cognitions, worry, and working memory impairment. Mediation analyses indicated that changes in psychotic experiences were mediated by changes in negative affect and related processes, but not memory impairment. The overall conclusion is that insomnia has a causal role in the occurrence of certain psychotic experiences, and that a key route is via negative affect.

Impact of Adverse Childhood Experiences on Psychotic-Like Symptoms and Stress Reactivity in Daily Life in Nonclinical Young Adults

Background

There is increasing interest in elucidating the association of different childhood adversities with psychosis-spectrum symptoms as well as the mechanistic processes involved. This study used experience sampling methodology to examine (i) associations of a range of childhood adversities with psychosis symptom domains in daily life; (ii) whether associations of abuse and neglect with symptoms are consistent across self-report and interview methods of trauma assessment; and (iii) the role of different adversities in moderating affective, psychotic-like, and paranoid reactivity to situational and social stressors.

Method

A total of 206 nonclinical young adults were administered self-report and interview measures to assess childhood abuse, neglect, bullying, losses, and general traumatic events. Participants received personal digital assistants that signaled them randomly eight times daily for one week to complete questionnaires about current experiences, including symptoms, affect, and stress.

Results

Self-reported and interview-based abuse and neglect were associated with psychotic-like and paranoid symptoms, whereas only self-reported neglect was associated with negative-like symptoms. Bullying was associated with psychotic-like symptoms. Losses and general traumatic events were not directly associated with any of the symptom domains. All the childhood adversities were associated with stress reactivity in daily life. Interpersonal adversities (abuse, neglect, bullying, and losses) moderated psychotic-like and/or paranoid reactivity to situational and social stressors, whereas general traumatic events moderated psychotic-like reactivity to situational stress. Also, different interpersonal adversities exacerbated psychotic-like and/or paranoid symptoms in response to distinct social stressors.

Discussion

The present study provides a unique examination of how childhood adversities impact the expression of spectrum symptoms in the real world and lends support to the notion that stress reactivity is a mechanism implicated in the experience of reality distortion in individuals exposed to childhood trauma. Investigating the interplay between childhood experience and current context is relevant for uncovering potential pathways to the extended psychosis phenotype.

Unravelling psychosis: psychosocial epidemiology, mechanism, and meaning

This paper reviews a revolution in our understanding of psychosis over the last 20 years. To a major extent, this has resulted from a process of cross-fertilization between psychosocial epidemiology and cognitive behavior therapy for psychosis (CBT-p). This encouraged complementary strategies for the acquisition and analysis of data. These include the use of a range of dependent variables related to psychosis, and the exploitation of data from cross-sectional and longitudinal epidemiological surveys, virtual reality experiments, experience sampling methodology, and treatment trials. The key element is to investigate social and psychological measures in relation to each other. This research has confirmed the role of the external social world in the development and persistence of psychotic disorder. In addition, several psychological drivers of psychotic experiences have been identified. There is now persuasive evidence that the influence of social factors in psychosis is significantly mediated by non-psychotic symptoms, particularly mood symptoms and other attributes of affect such as insomnia. Psychotic symptoms are also driven by reasoning biases such as jumping to conclusions and belief inflexibility, though little is known about social influences on such biases. It is now clear that there are many routes to psychosis and that it takes many forms. Treatment of all kinds should take account of this: the dependence of CBT-p on a detailed initial formulation in terms of psychological processes and social influences is an example of the required flexibility. Individual mediators are now being targeted in specific forms of CBT-p, with good effect. This in turn corroborates the hypothesized role of non-psychotic symptoms in mediation, and attests to the power of the approaches described.