Sexual abuse and suicide attempt in bipolar type I patients

Bipolar disorder (BD) is the psychiatric diagnosis that carries the highest risk for suicide behavior. Many different factors are associated with suicide behavior in BD, such as genetics,¹ first-episode bipolarity,² and early life adversities (ELA).³ However, specifically concerning ELA, some controversy persists about what types of adversity would contribute or not to suicidal behavior in patients with BD.³ Within this context, we conducted a study of all early life stressors (physical and emotional negligence and physical, emotional, and sexual abuse) and their associations with suicide behavior in BD.

We enrolled 47 BD type 1 (BD-I) patients aged 18 to 65 years. All patients lived in Belo Horizonte or neighboring areas and were receiving regular follow-up at the Núcleo de Transtornos Afetivos, Universidade Federal de Minas Gerais (UFMG). Our routine patient assessment protocol is fully detailed elsewhere.¹ Briefly, the diagnosis was established using a structured diagnostic interview (Mini International Neuropsychiatric Interview, MINI-PLUS). We only included BD-I patients in euthymia, defined as a score < 8 in the Young Mania Rating Scale (YMRS) and Hamilton Depression Rating Scale (HAM-D). We also evaluated the frequency, intent, and lethality of suicide attempts, using Beck’s Suicide Intent Scale. For the purpose of this study, ELA was assessed using the Childhood Trauma Questionnaire.⁴

The study was approved by the UFMG Research Ethics Committee. Written informed consent was obtained from all participants after a complete description of the study had been provided.

Overall, 23 patients (48.9%) in our sample had a history of at last one previous suicide attempt, with mean frequency of 1.67±0.89, and 24 (51.1%) did not. No significant statistical differences were found concerning socio-demographic and/or clinical characteristics between the suicidal or non-suicidal groups in variables classically associated with suicidal behavior, such as gender and comorbidities (Table 1).

Table 1
Sociodemographic parameters, clinical features, and childhood trauma events of 47 bipolar patients stratified by history of suicide attempt

Variable	Suicide (n=23)	No suicide (n=24)	p-value
Female gender	14 (60.8)	14 (58.3)	0.86
Age	43.1±12.2	39.3±10.6	0.27
Marital status
Married/living with partner	8 (34.8)	10 (41.6)
Single/divorced/widowed	15 (65.2)	14 (48.4)	0.63
Educational attainment, years	11.9±4.2	11.3±5.1	0.65
Age at first mood episode, years	26.7±9.6	25.1±8.4	0.52
History of psychiatric hospitalization	15 (65.2)	15 (62.5)	0.85
At least one comorbid diagnosis	14 (60.8)	12 (50.0)	0.45
Alcohol abuse or dependence	9 (39.1)	6 (25.0)	0.30
Physical negligence	7.7±3.4	8.1±4.3	0.71
Emotional negligence	10.3±5.9	9.4±6.2	0.54
Physical abuse	8.9±5.5	7.3±4.6	0.17
Emotional abuse	9.6±5.1	9.0±4.5	0.71
Sexual abuse	11.2±8.2	6.9±5.1	0.03
Total	47.7±22.1	41.0±18.5	0.29

• Data presented as n (%) or mean ± standard deviation.

Using the Shapiro-Wilk W and Mann-Whitney U tests and binary logistic regression, we found that BD-I patients with a lifetime suicide attempt exhibited significantly higher scores for sexual abuse (z = -2.093; p = 0.036, r = -0.31) than BD-I patients without a history of suicide attempt. However, we failed to find differences in any of the other ELA factors studied (Table 1).

Furthermore, we constructed a logistic regression model with the sexual abuse score. The results showed that sexual abuse contributed significantly to suicidal behavior (χ² ₍₁₎ = 4.69, df = 1, n=47; p = 0.03) in this population, accounting for 9.5% (Cox and Snell R²) to 12.7% (Nagelkerke R²) of the variance of the dependent variable. The Exp(β) and confidence interval was 1.102 (95% confidence interval 1.001-1.214).

A large body of evidence is currently available to help explain the link between ELA, particularly sexual abuse, and suicidal behavior (mediated for example by impulsivity and aggressivity), as well the molecular epigenetic mechanisms underlying those behaviors.⁵ To our knowledge, this was the first study to assess ELA and suicidal behavior in a Brazilian BD sample. Even considering some limitations (retrospective design and small sample size), our findings reinforce the idea that identifying child sexual abuse in BD patients may help psychiatrists define high-risk groups for suicidal behavior, and highlights the need to address this hidden epidemic.

Disclosure

The authors report no conflicts of interest.

This study was supported by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo è Pesquisa do Estado de Minas Gerais (FAPEMIG).

References

• ¹
  Neves FS, Malloy-Diniz LF, Romano-Silva MA, Aguiar GC, de Matos LO, Correa H. Is the serotonin transporter polymorphism (5-HTTLPR) a potential marker for suicidal behavior in bipolar disorder patients? J Affect Disord. 2010;125:98-102.
• ²
  Neves FS, Malloy-Diniz LF, Barbosa IG, Brasil PM, Corrêa H. Bipolar disorder first episode and suicidal behavior: are there differences according to type of suicide attempt? Rev Bras Psiquiatr. 2009;31:114-8.
• ³
  Leverich GS, Post RM. Course of bipolar illness after history of childhood trauma. Lancet. 2006;367:1040-2.
• ⁴
  Grassi-Oliveira R, Stein LM, Pezzi JC. [Translation and content validation of the Childhood Trauma Questionnaire into Portuguese language]. Rev Saude Publica. 2006;40:249-55.
• ⁵
  Labonté B, Turecki G. Epigenetic effects of childhood adversity in the brain and suicide risk. In: Dwivedi Y, editor. The neurobiological basis of suicide. Boca Raton: CRC Press; 2012 p. 256-84.

Publication Dates

• Publication in this collection
  June 2015

History

• Received
  24 Nov 2014
• Accepted
  25 Jan 2015