Childhood trauma in bipolar affective disorder: A case control study

Abstract

Background:

The etiology of Bipolar Affective Disorder (BPAD) is influenced by a variety of factors, possibly related to gene-environment interactions. Childhood trauma (CT) has been associated with an increased risk of developing BPAD. It also impacts the course of illness. The association of subcomponents of CT with BPAD and its various characteristics has not been studied in detail.

Aim:

This study was conducted to evaluate the association of CT with BPAD and compare it with age and sex-matched healthy controls.

Materials and Methods:

Fifty cases of BPAD diagnosed as per International Classification Diseases 10 (Diagnostic Criteria for Research) and 50 years age and sex-matched healthy control were studied. The required sample size was 38. Assessment of CT was done using the Childhood Trauma Questionnaire and statistical methods were applied.

Results:

Among all cases of BPAD, 38 (76%) cases had experienced moderate to severe CT as compared to 10 (20%) of controls. This was statistically significant. All subtypes of CT were significantly associated with BPAD as compared to healthy controls. Among subtypes, emotional abuse had the highest association with BPAD (odds ratio 7.37, confidence interval 1.98-27.31).

Conclusion:

CT is significantly associated with BPAD. All subtypes of CT are associated with BPAD and among them, emotional abuse appeared to exert the biggest impact. A multicentric study with larger sample sizes will further substantiate this finding regarding subtypes.

Bipolar Affective Disorder (BPAD) affects more than 1% of the global population.[1] The etiology of BPAD is influenced by a variety of factors possibly related to gene-environment interactions.[2] Critical environmental components are related to the later development of BPAD in adult life, such as childhood trauma (CT).[3] Cross-sectional studies have documented that CT is more common among individuals with BPAD, as compared to the general population, with rates up to 63% described, when multiple trauma events are experienced by an individual.[3,4,5] CT is often described as serious adverse childhood experiences. It is the most intensive and frequently occurring source of stress that children may suffer early in life.[6] Such experiences include abuse (physical, emotional, or sexual), neglect (emotional or physical), and household dysfunction (e.g. parental mental health and substance abuse problems, violence or discord between parents or caregivers, and having an incarcerated family member).[7] Approximately 30% to 50% of individuals with BPAD have experienced traumatic events in childhood.[8]

CT is associated with more severe clinical features of BPAD, including an earlier age of onset, an increased risk of at least one-lifetime suicide attempt, rapid cycling, an increased number of mood episodes, and substance misuse.[9,10] Early intervention strategies and approaches have been proposed to potentially prevent these individuals from developing chronic illness over time.[9]

The specific role of each trauma subtype of CT (emotional, physical, or sexual abuse) remains a subject of debate. There are few studies in the available literature that focus on CT as a potential risk factor for BPAD. Hence, this study was undertaken to delineate association of CT in patients with BPAD and to evaluate the association among subtypes of CT.

MATERIALS AND METHODS

This was a hospital-based, case-control study conducted at the Psychiatry department of a large tertiary care hospital. The sample size was calculated for 80% power of detecting a difference with a 5% level of significance.[11] Minimum required sample calculated was 38 (N = 38). We have studied 50 cases of BPAD fulfilling the inclusion/exclusion criteria and 50 years age and sex-matched healthy controls for comparison. The study was conducted between December 2019 and September 2021 and was slightly prolonged due to the COVID-19 pandemic. The inclusion criteria were all cases of BPAD, diagnosed as per International Classification Diseases 10 (Diagnostic Criteria for Research) aged between 18 and 65 years. Both BPAD type I (episodes of mania and may involve depression) and type II (includes hypomania and depression) were included.

Exclusion criteria were mood disorders due to organic cause or substance use, the presence of a family history of BPAD, and the presence of any neurological disorder impacting emotions. All subjects were administered a Childhood Trauma Questionnaire (CTQ). CTQ is a self-report assessment questionnaire for adults that inquires about five types of maltreatment that occurred during childhood [Table 1].[9]

Table 1.

Childhood trauma subtypes in childhood trauma questionnaire

Trauma subtype	Definition
Emotional neglect	Failure of caretakers to meet children’s basic emotional and psychological needs, including love, belonging, nurturance, and support
Emotional abuse	Verbal assaults on a child’s sense of worth or wellbeing or any humiliating or demeaning behaviour directed toward a child by an adult or older person
Physical neglect	Failure of caretakers to provide for a child’s basic physical needs, including food, shelter, clothing, safety, and healthcare
Physical abuse	Bodily assaults on a child by an adult or older person that posed a risk of or resulted in injury
Sexual abuse	Sexual contact or conduct between a child aged less than 18 years of and an adult or older person

CTQ has 28 items and takes 5-7 minutes to complete. Each item is rated on a Likert scale with responses varying from “never true” to “very often true”. For this study, the scale was translated into Hindi. The Hindi translation was validated using 100 randomly selected normal subjects. Initially, 50 subjects were given the English version and 50 the Hindi one. After 1 week, it was reversed. The results did not show any statistically significant difference. The CTQ assessed for moderate to severe CT. On the basis of the cut-off score, we classified whether cases and controls had a history of CT.[12] CTQ had been validated in terms of psychometric test properties.[13] Cronbach’s alpha for the factors ranged from 0.79 to 0.94, indicating high internal consistency. The CTQ also demonstrated good test-retest reliability over a 2-month to 6-month interval.[12]

Ethical clearance was obtained from the Institutional Ethics Committee prior to commencing interaction with patients. Informed consent was obtained by researchers after self-introduction. Biographical, sociodemographic, medical, and mental health data were then recorded on a specially designed proforma. All critically ill patients, those who did not give written consent, and those actively symptomatic or distressed were excluded from the study.

Data analysis was done by using SPSS (Statistical Package for Social Sciences) Version 25.0. Categorical data are presented as numbers and percentages (%) and quantitative data in terms of mean and standard deviation. Categorical variables were analyzed using the Chi-square test. Quantitative variables were analyzed using an independent Student’s t-test. The odds ratio was calculated for each subset and a P value < .05 was considered as statistically significant [Figure 1].

Figure 1.

Methodology of the study

RESULTS

The findings of this study are from 50 consecutive cases of BPAD who reported to Psychiatry OPD for follow-up in tertiary care hospital, which was compared with age-matched and sex-matched controls. Forty males and 10 females were included in the study, with similar age-matched and sex-matched controls. Mean age of participants was 36.14 (±12.36) years and among cases, 92% were BPAD type I. Thirty eight (76%) cases and 10 (20%) controls had moderate to severe CT as per cut-off score of CTQ [Figure 2]. Sixty five percent of cases with a history of moderate to severe CT had onset of BPAD in their 20s (between 20 and 29 years). The mean number of the depressive episodes among cases with CT were 1.53 as compared to 1.50 for cases without CT. Similarly, mean number of episodes of mania in patients with CT was 2.71 as compared to the mean score of 2.17 for cases without CT [Figure 3]. Twenty six point three percent cases of BPAD with moderate to severe CT gave a history of at least one lifetime suicide attempt in comparison to 8.33% cases with mild CT or no trauma [Figure 4]. Other sociodemographic characteristics of cases and controls like marital status, education, occupation, monthly income, family type, birth order, and place of residence were not significantly different between cases and controls [Table 2]. Moderate to severe emotional abuse was reported in 32% cases of BPAD with an odds ratio of 7.37. Thirty eight percent of cases with BPAD had moderate to severe physical neglect with an odds ratio of 5.51. Sexual abuse was in 12% of cases with an odds ratio of 3.13. Emotional neglect was reported in 34% of cases with an odds ratio of 3.77. Moderate to severe physical abuse was seen in 20% of cases with an odds ratio of 2.87 [Figure 5].

Figure 2.

Childhood trauma in cases of bipolar affective disorder vs. healthy controls

Figure 3.

Number of episodes of depression and mania/hypomania among those with childhood trauma

Figure 4.

Childhood trauma and suicide attempts (N = 50)

Table 2.

Sociodemographic profile of cases and controls

Sr. No	Variables	Cases	Control	P value
1.	Mean Age	36.14 years (± 12.36)	36.14 years (±12.36)	0.999NS
2.	Sex
	Male	40	40	0.999NS
	Female	10	10
3.	Residence
	Rural	56%	68%	0.216NS
	Urban	44%	32%
4.	Birth order
	1-2	74%	86%	0.294NS
	3-4	24%	12%
	>4	2%	2%
5.	Marital Status
	Unmarried	38%	30%	0.120NS
	Married	56%	70%
	Divorcee	6%	-
6.	Education
	No formal education	4%	0%	0.164NS
	Up to higher secondary	64%	78%
	Graduate	32%	22%
7.	Occupation
	Unemployed	38%	22%	0.154NS
	Unskilled	14%	22%
	Skilled worker	46%	48%
	Clerical	0	4%
	Semi-professional	0	4%
	Professional	0	0
8.	Monthly Income
	No formal income	38%	22%	0.306NS
	<30000	14%	20%
	30000-50000	42%	54%
	>500000	6%	4%
9.	Family type
	Joint	30%	40%	0.295NS
	Nuclear	70%	60%

Cases and controls were comparable

Figure 5.

Odds ratio of subtypes of childhood trauma questionnaire (N = 50)

DISCUSSION

The mean age of individuals in most studies of the CT association with BPAD was in the range of 34 to 43 years.[14,15] A similar age range was also seen in cross-sectional studies of BPAD on an OPD basis among the Indian population.[16] Etain et al. 2013 showed that childhood adversity was significantly associated with early age of onset of BPAD.[10] Our study also found that there is a slightly early age of onset in cases of BPAD with moderate to severe CT. The mean age of onset of BPAD with moderate to severe CT was 25.05 (±8.61) years and for those with no or mild CT was 27.75 (±8.04) years. However, it was not significant.

Some studies have shown that BPAD type I is associated with greater levels of childhood adversity.[17,18] Marwaha et al. in 2017 similarly found that the BPAD type I group reported significant childhood abuse.[18] In our study, 46 (92.0%) of cases had BPAD type I and 4 (16.0%) had BPAD type II. A nearly equal percentage of BPAD type I (74%) and BPAD type II (75%) had moderate to severe CT. This might be due to the lesser number of BPAD type II cases in our study.

Garno et al.[19] in 2005 reported that mean number of manic/hypomania episodes and of depressive episodes with a history of CT was more, than without history of CT. However, in this study, the distribution of mean number of episodes depressive and hypomanic/manic episodes did not differ significantly between cases of BPAD with CT or without CT.

Leverich et al.[20] in 2002 reported that those who endorsed a history of child or adolescent physical or sexual abuse had a higher rate of suicide attempts. Similar findings were also reported by Etain et al.[10] that both emotional and sexual abuse were independent predictors for history of suicide attempts. Also, Garno et al.[19] indicated a significant association between lifetime suicide attempts and severe CT. This study found an increased percentage of attempted suicide among cases of BPAD with moderate to severe CT. Twenty six point three percent cases of BPAD with moderate to severe CT have a history of at least one lifetime suicide attempt in comparison to 8.33% cases without or mild CT.

Studies have revealed that patients with BPAD have experienced negative events in childhood more often than healthy subjects.[21] Garno et al.[19] in 2005 showed that 51% of BPAD reported CT. This study has similar findings suggesting that history of moderate to severe CT is often encountered with BPAD. Thirty one (77.5%) male cases of BPAD patients and eight (20%) male controls had a history of moderate to severe CT, while seven (70%) female cases of BPAD patients and two (20%) female controls had a history of moderate to severe CT. This was similar to the study of Etain et al.[10] 2013, which indicated a higher level of CT in both male and female cases of BPAD. Several studies reported that females with BPAD reported CT more frequently than males.[10,22] The slightly lesser number of CT reported by females in our study could possibly be due to a tendency to not report abuse in the Indian culture.

In this study among subtypes, emotional abuse has been reported in 32% cases of BPAD, 38% cases had physical neglect, 12% reported sexual abuse, 34% reported emotional neglect, and 20% reported physical abuse. Similar findings were also shown by Daruy-Filho et al.[23] in 2011, where emotional abuse has been reported by 37% cases of BPAD, 24% reported physical abuse, 24% emotional neglect, 21% sexual abuse, and 12% physical neglect. In addition, half of patients with a history of moderate to severe CT have more than one subtype of CT. Garno et al.[20] in 2005, also reported that one-third of BPAD patients had more than one type of trauma.

Childhood trauma sub-types

1. Emotional abuse: Odds ratio was 7.37 suggesting that emotional abuse is highly associated with BPAD. The meta-analysis of Norman et al.[24] in 2012 reported that CT was highly associated with BPAD and among subtypes, emotional abuse was highly associated with odds ratio of 3.06. In a systemic review by Palmier-Claus et al. in 2016, CT was 2.63 times (confidence interval: 2.00-3.47) more likely to have occurred in BPAD when compared with controls.[17] Etain et al. in 2010 similarly reported that among the types, emotional abuse has a strong association with BPAD.[10]

2. Physical Neglect: Odds ratio in this study was 5.51 suggesting that physical neglect was significantly associated with BPAD. This was in consonance with Watson et al.[3] in 2014, who found physical neglect to be a significant CTQ subtype associated with a diagnosis of BPAD.

3. Sexual abuse: Odds ratio for sexual abuse in this study was 3.13 indicating that it was significantly associated with BPAD. Our findings were in consonance with Álvarez et al. in 2011, where sexual abuse was more frequently reported by females than males, while physical abuse was more frequently reported by males.[9,22]

4. Emotional neglect: Odds ratio was 3.77 indicated that emotional neglect was significantly associated with BPAD. Our finding was in consonance with Watson et al.[3] in 2014, who revealed emotional neglect to be associated with a diagnosis of BPAD.

5. Physical abuse: Odds ratio was 2.87 indicated that physical abuse was significantly associated with BPAD. This was in consonance with Romero et al.[25] in 2008, who found that 20% of cases of BPAD had experienced physical abuse. This study also highlighted the early onset of BPAD with a history of CT.

This study has many strengths. CTQ is a structured, reliable, and validated instrument. Age-matched and sex-matched controls were used, which improved the internal validity of study. Participant cases and age-matched and sex-matched controls were from a heterogeneous geographical origin, representing the entire Indian population which improved the external validity of the study. All the subtypes of CT were studied to have a better understanding of their association with BPAD.

Limitations of this study include the possible presence of subthreshold affective symptoms which might have influenced individuals’ recall of past traumatic experiences. This study was based entirely on retrospective and self-report data, which was not independently verified from other informants and some recall bias may be expected.

CONCLUSIONS

This study revealed that 76% of cases of BPAD had suffered moderate to severe CT. All subtypes of CT were significantly associated with BPAD, when compared with controls. Specific associations between the BPAD and different subtypes of CT, emotional abuse, and physical neglect seem to have the biggest impact.

CT should be assessed in all cases of BPAD and subsequent focused intervention might impact the mean number of episodes, their severity, and suicide attempts. Early intervention strategies and approaches have been proposed, which are directed at CT to potentially prevent these individuals from developing chronic illness over time. A multicentric study involving larger sample size would help in clearly demarcating role of subtypes CT in BPAD.

Ethical concern

Ethical clearance was taken by Institutional ethics committee, AFMC, Pune vide reference letter no. IEC/Oct/2019 dt. Oct 18, 2019.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.