Summary: Study reveals a strong association between emotional abuse experienced during childhood and an increased risk of developing schizophrenia-like symptoms in adulthood.
Source: University of Hertfordshire
A new University of Hertfordshire study has, for the first time, identified a strong link between childhood emotional abuse and schizophrenia-like experiences in healthy adults, such as paranoia, hearing voices, and social withdrawal.
Researchers say that those who have experienced emotional abuse in early life are 3.5 times more likely to have schizophrenia-like experiences in adulthood. Researchers also say that the more significant the abuse, the more severe the schizophrenia-like experiences adults have.
The research, published in PLOS ONE, is the first to summarize and quantify studies (25 in total) that have explored the relationship between childhood trauma and schizophrenia-like experiences in over 15,000 healthy people.
Researchers at the University of Hertfordshire analyzed the findings of past research to see whether specific types of abuse, such as emotional, sexual and physical abuse, as well as emotional and physical neglect, increased the likelihood of having schizophrenia-like experiences in later life.
They found a much stronger link between childhood emotional abuse and schizophrenic-like experiences in adulthood than other types of childhood abuse.
The relationship between childhood trauma and schizophrenia, a serious mental health condition, is well known. However, far less research has examined the impact of childhood trauma on the prevalence of less severe schizophrenia-like experiences in healthy adults.
Researchers believe their findings could show that schizophrenia is a condition on a spectrum, like autism, where healthy people can have schizophrenia-like episodes without meeting the diagnosable threshold.
University of Hertfordshire researcher Dr. Diamantis Toutountzidis led on this study with supervision from Keith Laws, Professor of Neuropsychology at the University.
Dr. Toutountzidis says that “emotional abuse differs from other types of abuse. It is more common, often happens over longer periods of time, and is not treated in law the same way that physical or sexual abuse is.”
“Our research has shown a significant link between childhood emotional abuse and schizophrenia-like experiences in healthy adults, and that emotional abuse is a stronger predictor of schizophrenia-like experiences than other types of abuse.
“This is something mental health professionals should consider when looking to tackle the root causes of schizophrenia-like experiences in people suffering from them.”
Professor Laws added that their “research has opened the door to future studies that help better understand how specific types of childhood abuse are linked to specific schizophrenia-like experiences much later in life. It will also help us start to understand why such trauma is linked to disorders like schizophrenia in some, while others experience milder manageable experiences.”
Childhood trauma and schizotypy in non-clinical samples: A systematic review and meta-analysis
The association of early life adversities and psychosis symptoms is well documented in clinical populations; however, whether this relationship also extends into subclinical psychosis remains unclear. In particular, are early life adversities associated with increased levels of schizotypal personality traits in non-clinical samples?
We conducted a systematic review and meta-analysis of associations between early life adversities and psychometrically defined schizotypal traits in non-clinical samples. The review followed PRISMA guidelines.
The search using PubMed, Web of Science and EBSCO databases identified 1,609 articles in total. Twenty-five studies (N = 15,253 participants) met eligibility criteria for the review. An assessment of study quality showed that fewer than half of all studies were rated as methodologically robust.
Meta-analyses showed that all forms of childhood abuse (emotional, physical and sexual) and neglect (emotional and physical) were significantly associated with psychometric schizotypy. The association of schizotypy traits with childhood emotional abuse (r = .33: 95%CI .30 to .37) was significantly larger than for all other form of abuse or neglect. Meta-regression analyses showed that the physical abuse-schizotypy relationship was stronger in samples with more women participants; and the sexual abuse-schizotypy relationship was stronger in younger samples.
The current review identifies a dose-response relationship between all forms of abuse/neglect and schizotypy scores in non-clinical samples; however, a stronger association emerged for emotional abuse. More research is required to address the relationship of trauma types and specific symptom types.
Future research should also address the under-representation of men.