Blunted stress reactivity reveals vulnerability to early life adversity in young adults with a family history of alcoholism

Abstract

Background and aims: People with blunted stress reactivity have poor impulse control and also show increased risk for alcoholism. Exposure to early life adversity (ELA) contributes to blunted reactivity, but individual differences in susceptibility to ELA are not well understood. This study aimed to determine whether exposure to ELA has a greater impact on stress reactivity in young adults with a family history of alcoholism (FH+) compared with young adults with no family history of alcoholism (FH-).

Design: Observational study using linear modeling.

Setting: Oklahoma, USA.

Participants: Seven hundred and nine young adults (398 females) recruited through community advertisement.

Measurements: We obtained heart rates and cortisol levels in subjects while undergoing public speaking and mental arithmetic stress compared with a resting control day (1418 test sessions). ELA was quantified as 0, 1 or > 1 adverse events experienced by age 15 years. FH+ people had one or two parents with an alcohol use disorder, and FH- controls had no such history for two generations.

Findings: Increasing levels of ELA predicted progressive blunting of cortisol and heart rate reactivity for the whole sample (Fs = 4.57 and 4.70, Ps ≤ 0.011), but examination by FH status showed that the effect of ELA was significant only among FH+ (Fs ≥ 3.5, Ps < 0.05) and absent in FH- (Ps > 0.40). This difference in ELA impact was not explained by the cortisol diurnal cycle or subjective evaluation of the stressors.

Conclusions: People with a family history of alcoholism appear to be vulnerable, in terms of changes to physiological stress response, to the impact of exposure to early life adversity while people with no family history of alcoholism appear to be resilient. Blunted stress reactivity may reflect differential vulnerability to early life adversity in young adults with a family history of alcoholism.

Keywords: Cortisol; family history of alcoholism; heart rate; life-time adversity; public speaking; stress reactivity.

Figure 1.

Cortisol responses (top panels) and heart rate responses (bottom panels) to a mental stress protocol. ELA refers to low, moderate, and higher levels of early life adversity (ELA = 0, 1, >1 forms of adversity experienced in childhood and adolescence). FH refers to a negative or positive family history of alcoholism (FH−, FH+). Left panels show data by FH− and FH+ groups. Middle panels show data by exposure to ELA. Right panels show data for FH x ELA groups.