Article summary with Maltreatment in childhood substantially increases the risk of adult depression and anxiety in prospective cohort studies: Systematic review, meta-analysis, and proportional attributable fractions by Li a.o. - 2015

Preface

There is a strong relationship between childhood maltreatment and the development of depression and anxiety disorders. There are several neurobiological mechanisms that contribute to the emerge of psychopathology.

• Stress

• Structural brain differences

• Functional brain differences

• Genetics and epigenetics and vulnerability

What is wrong with previous research on the relationship between child abuse and psychiatric disorders?

If there is childhood abuse, this also impacts the development of affective processing abilities, adaptation in school, self-system processes, relationships with peers and attachment relationships. The biggest causes of morbidity because of psychiatric disorders are depression and anxiety. Children coming from abusive environments and families are significantly more prone to develop depressive -and anxiety symptoms. The direct relationship between child maltreatment and psychiatric disorders has been proven repeatedly, however the measurement of maltreatment is susceptible to bias and false memory. This is because most studies review cross-sectional -or use recall to assess maltreatment.

The reason for this is that a large part of people that have been interviewed in their adult life do not report child abuse or maltreatment. Mental health is related to filtering out harmful -and negative memories. The mind will represent them in a non-threatening manner. Therefore, people with good functioning forget negativity in their past and people that function poorly exaggerate negativity. Thus, current mental health influences reporting of negative childhood experiences. Also, cross-sectional studies fail to establish the temporal relationship between the outcomes of risk factors.

There is too little research on the potential prospective impact of maltreatment reduction on psychiatric disorders. People attribution factors (PAFs) can be used to point out the reduction of a disease in a population. It shows what would occur if the risk factor exposure decreases to an ideal exposure level. It could potentially help judging priorities on health action.

What method is used in the current study?

This study is a systematic review and meta-analysis, of English articles published in the last 25 years. Electronic databases and grey literature were searched for studies with criteria for depression or anxiety together with a non-recall measurement of childhood maltreatment. A systematic meta-study is done to analyse the results and the reviewed articles were grouped for five analysis:

1. Maltreatment and depression (anything).

2. Maltreatment and anxiety (anything).

3. Physical abuse and depression -or anxiety.

4. Sexual abuse and depression -or anxiety.

5. Neglect and depression -or anxiety.

The constructs: study quality, heterogeneity and publication bias were reviewed as well. The initial screening of titles and abstracts resulted in 199 remaining papers. Finally, eighty-eight articles were found matching the criteria. Potential preventive impact was measured using population attributable fractions (PAFs).

What were the results of this study?

The odds ratio (OR) was calculated between maltreatment in general and depression (OR = 2.03). This indicates that individuals with any type of child maltreatment have 2.03 times more chance get depression than others. For the relation between any type of maltreatment the outcome was: OR = 2.70. Also, the OR was calculated between specific types of maltreatment and depression or anxiety disorders. These include physical abuse, sexual abuse and neglect. The relationship between physical abuse and depression or anxiety was OR = 2.00 meaning children that were abused in childhood are two times more likely to develop depression -or anxiety than children without maltreatment. For sexual abuse the chance was 2.66 times higher and for neglect this chance was 1.75 times.

After this initial analysis the PAFs were calculated to show potential depression and anxiety cased that could be prevented if child abuse would be reduced worldwide. The PAFs suggest that about fifty percent of depression and anxiety cases are caused by self-reported childhood maltreatment. A reduction in maltreatment of ten to fifteen percent could prevent millions of depressions -and anxiety cases worldwide.

What did the researchers conclude?

There are significant relationships between the various types of maltreatment (i.e. neglect, physical and sexual abuse) and psychiatric disorders later in life. Childhood maltreatment should be viewed as a risk factor for depression and anxiety disorders. All types of child maltreatment are associated with developing psychological disorders. This study is the first in estimating the projected decrease of mental disorders by reducing child abuse worldwide. The conclusion is that there is evidence for childhood maltreatment as increasing the risk for depression and anxiety. Furthermore, it reinforces the need for more policies and programs to prevent the occurrence.

What are the limitations of measures of child maltreatment?

There are strengths and limitations to both self-reported and informant measures of child abuse. The disadvantage of self-report is that it relies on retrospective memory, which is often flawed. Informant reports are often displaying the most severe cases of maltreatment, such as neglect or emotional abuse. Self-report measures work better for cases of sexual abuse, which might be invisible to informants. Also, informant studies have the drawback that they can underestimate abuse because they are based on short-period reports by a professional of child protective service. When chronicity is not considered, childhood maltreatment can be overestimated. When measurements are taken on a one-time basis, maltreatment can be underestimated.

What is the advantage of using PAFs?

PAFs provide a quantitative measure of impact on the prevalence of depression and anxiety that could be accomplished by the reduction of child maltreatment. A decreasing amount of child abuse can prevent cases of mental illness and should be a target for mental health promotion. Child abuse is both a threat for a child’s development as lifetime perspectives. Early childhood experience sets the trajectory for future risk behaviours. Interventions and services should be improved to enhance the populations’ overall mental health.

What are the strengths of the current study?

The pooled findings from longitudinal and cohort studies that have externally documented cases of child abuse are a strength of this study. The use of these studies decreases the issue of recall bias, false memories and effort after meaning. The reviewed studies are quite recent, and the quality was controlled for. Furthermore, the use of PAF estimates show the decrease of depression and anxiety by reducing child maltreatment.

What are the limitations of the current study?

Limitations are that there is only a small number of reviewed articles. Unfortunately, not more studies met the requirements for the inclusion criteria. The studies that are reviewed are not representative for the world’s population. These studies only review the USA, Australia and New Zealand. Studies from developing countries were not included. The PAF measures might have been influenced by the inconsistent measures between global prevalence of maltreatment and the connection between maltreatment and depression -and anxiety. The third limitation is that heterogeneity was high in some of the analysis. This indicates substantial variation in the connection between child abuse and mental health in the outcomes. Therefore, these measures should be standardized. Potential moderators in child abuse should be identified. Finally, only cases without recall bias are included in this study meaning that the reported cases are more severe.