Fluctuations in daily PTSD symptoms are related to proximal alcohol use: a micro-longitudinal study of women victims of intimate partner violence

ABSTRACT

Background: One-third of women who experience intimate partner violence (IPV) are identified as having alcohol use problems. Yet, little research has examined factors that may increase the risk of alcohol use among this high-risk population. Objectives: This study overcomes limitations of previous research by using micro-longitudinal methods to examine how fluctuations in PTSD symptoms throughout the day are associated with proximal drinking behavior and whether these associations are related to individuals’ overall PTSD severity and race/ethnicity. Methods: Using phone-based interactive voice response, 244 female victims of current IPV reported their PTSD symptoms and drinking four times daily for 14 days. Results: Results indicated positive associations between PTSD symptom cluster severity and drinking level at the person, daily and within-day levels. The effects of within-person fluctuations in daily levels of PTSD severity on levels of drinking were stronger for individuals with lower PTSD severity. No evidence was found for within-person differences on time-lagged effects of PTSD on drinking or by racial/ethnic group. Further, in time-lagged models no evidence was found for reverse causation whereby alcohol use predicts increased PTSD symptom severity. Conclusions: Findings suggest that IPV-exposed women use alcohol to alleviate their PTSD symptoms at the micro-process level and that prevention and treatment efforts targeting PTSD symptoms may be useful in reducing alcohol use in this population. Further, these efforts should consider the overall severity of PTSD symptoms experienced given the differential findings among women with higher vs. lower PTSD symptom severity.

KEYWORDS:

• Posttraumatic stress disorder
• intimate partner violence
• alcohol use
• women
• micro-longitudinal data

Notes

1. For quantitative predictors, the exp(b) coefficient corresponds to the increase in the rate of drinking for a unit increase in the predictor. Values for exp(b) less than 1.0 correspond to the rate decrease.

2. The Y-axis in this figure corresponds to the mean drinking levels across the 4 within-day intervals, not the total day sum.

3. For this interaction and the one shown in Figure 2, we used these values instead of plus/minus 1 SD from the mean because the moderators were positively skewed and using the conventional minus 1 SD below the mean to convey low levels was out of the range of the observed values.

4. These models were identical to the drinking level models, except PTSD cluster severity at interval t+1 is the dependent variable and we replaced mean levels of PTSD clusters severity as a level 3 predictor with mean drinking level.

5. For descriptive purposes, we report standardized partial slopes as an effect size. We calculated these values by standardizing the data prior to model estimation. All significance tests are based on the unstandardized slopes.

Additional information

Funding

This project was supported by Grant No. R01DA031275, awarded by the National Institute on Drug Abuse to Tami Sullivan/Yale University. Support also was provided by the NIDA grants K23 DA039327 (NHW) and L30DA038349 (NHW)..