Life-stress and reactivity by gender in a longitudinal birth cohort at 30 and 35 years Dr Geraldine McLeod; Associate Professor John Horwood; Professor David Fergusson; and Associate Professor Joseph Boden Department of Psychological Medicine, University of Otago, Christchurch 17 June 2016

Background Previous research has shown gender differences in reactivity to stressful life events Generally females report more incidents and greater distress One exception is the domain of employment/finance It is still unclear whether gender differences in stress reactivity are consistent across a series of life event domains in a longitudinal adult sample

Methods Christchurch Health and Development Study Longitudinal birth cohort of 1265 children born in females and 635 males Data has been collected at regular intervals until 35 years

Measures Life events questionnaire Social Readjustment Rating Scale (Holmes and Rahe, 1967) Life event scale by Henderson et al. (1981) Number of scale items (30 items at 30 years; 32 items at 35 years) Included: problems or changes in interpersonal relationships, illness/death; victimization; pregnancy/parenthood; and problems with employment/finances Some events may be seen as positive, but potentially disruptive or stressful eg, starting a new job or entering a cohabiting relationship

Measures At each assessment respondents reported life events for previous 12 months If an event was reported, the respondent was also asked “How distressed were you from this event?” 0 = no event 1 = not upset/distressed 2 = a little upset/distressed 3 = moderately upset/distressed 4 = very upset/distressed

Measures Two measures were constructed: The number of life events The distress per life event

Sample sizes Males 30 years = 478; Males 35 years = 463 Females 30 years = 509; Females 35 years = 499 Data analysis Data for the two assessments at ages 30 and 35 were pooled and analysed using a generalised estimating equation (GEE) modelling framework

Table 1. Mean (SD) number of life events for a series of life event domains Male Female DomainsMeans (SD) Cohen’s dp Interpersonal problems Pooled 30;35 years1.6 (2.2) 1.6 (2.4) Victimisation Pooled 30;35 years0.4 (0.8) 0.2 (0.7)0.27<0.001 Illness and death Pooled 30;35 years1.5 (1.5) 1.7 (1.7) Pregnancy and parenthood Pooled 30;35 years1.2 (1.7) 1.3 (1.8) Employment and finance Pooled 30;35 years2.1 (2.4) 1.9 (2.0) All domains Pooled 30;35 years7.1 (4.6) 7.2 (4.5)-0.887

Table 2. Mean (SD), n reported distress of respondents pooled across observations at 30;35 years, by gender Male Female DomainsMean (SD) Cohen’s d p Interpersonal problems Pooled 30;35 years2.1 (1.0) 2.5 (1.1) 0.37 <0.001 Pooled n Victimization Pooled 30;35 years3.4 (2.2) 3.7 (1.9) Pooled n Illness and death Pooled 30;35 years3.0 (0.8) 3.4 (0.7) 0.45 <0.001 Pooled n Pregnancy and parenthood Pooled 30;35 years1.3 (0.6) 1.5 (0.8) 0.29 <0.001 Pooled n Employment and finance Pooled 30;35 years1.6 (0.8) Pooled n All domains Pooled 30;35 years2.1 (0.7) 2.3 (0.8) 0.27 <0.001 Pooled n

Mediating factors Child and adolescent factors assessed years Depression Anxiety disorder Self-esteem Suicidal ideation Neuroticism Childhood sexual abuse assessed at 18 and 21 years Adult factors assessed at 30 and 35 years Depression Anxiety disorder Self-esteem

Table 3. Associations between gender and distress Unadjusted Adjusted DomainB (SE)p p Interpersonal problems0.379 (0.097)< (0.065)<0.001 Illness and death0.392 (0.043)< (0.047)<0.001 Pregnancy and parenthood0.254 (0.046)< (0.050)<0.001 All domains0.263 (0.035)< (0.038)<0.001

In summary Men and women reported exposure to a similar number of life events. Statistically significant gender differences in distress following exposure to interpersonal problems, illness/death, and pregnancy/parenthood. Women rated their experiences as more distressing than men. These associations were resilient to adjustment for a range of potential mediating factors. The effect sizes for the statistically significant differences were small- moderate

Conclusions Findings were consistent with previous research Except no gender difference for: Victimization. May be due to few respondents reporting this event Employment/finance. May be due to changes in normative gender-role expectations Life event distress impacts on females more However effect sizes were small Men are not unaffected by life event distress