Posttraumatic Stress and Risky Sex in Trauma-Exposed College Students: The Role of Personality Dispositions Toward Impulsive Behavior

Abstract

Posttraumatic stress disorder (PTSD) has been linked to risky sexual behavior (RSB). However, little is known regarding the role of impulsivity in this relation among college students. The present study examined the moderating role of impulsivity dispositions on the relation between PTSD symptoms and past-year RSB in a sample of 221 trauma-exposed undergraduate students (77.4% female). Two separate negative binomial regression models examined each impulsivity disposition’s unique moderating effect on the association between PTSD symptoms and high risk/casual sex. In the high risk model, significant interactions were found for the urgency dispositions, (lack of) premeditation and (lack of) perseverance, though the pattern of these relations differed across these dispositions. Only positive main effects for negative urgency and (lack of) premeditation emerged in the casual sex model. The present study expands on the limited literature on the role of impulsivity in the relation between PTSD and RSB in trauma-exposed college students.

Introduction

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), introduced several changes to the diagnosis of posttraumatic stress disorder (PTSD), including the addition of a new symptom: reckless and self-destructive behaviors (criterion E2).¹ It has long been recognized that individuals with PTSD frequently engage in risky behavior, defined as any action that renders a person susceptible to negative emotional, financial, physical or social consequences.² However, the addition of criterion E2 was made in response to evidence that engagement in potentially harmful and risky behaviors is a prevalent and characteristic feature of the PTSD diagnosis.³ Various types of risky behavior patterns have been identified among individuals with PTSD, such as self-harm,⁴ risky sexual behavior,^5–7 antisocial and aggressive behavior patterns,^8–9 and substance abuse problems.^10–11

Risky sexual behavior (RSB; e.g., unprotected sex, sex under the influence of drugs or alcohol, unprotected sex with multiple partners, sex in exchange for money or substances) has been frequently linked to PTSD symptoms across diverse populations, including among substance users,¹² those with childhood sexual abuse or other interpersonal trauma histories,^5,13–15 and incarcerated women.¹⁶ Although prior studies have broadly investigated RSB in college students, trauma history and PTSD symptoms have rarely been considered.

RSB is common among college students.¹⁷ On average, college students report having two or more sexual partners in the past year.^18–19 Risk for negative sexual health outcomes increases with the number of sex partners, particularly if one or more sexual encounters are unprotected.²⁰ College students report that 42–56% of recent vaginal, 69–80% of recent anal, and 94–95% of recent oral sex encounters did not involve use of a condom.^18–22 Unique developmental and environmental characteristics differentiate the RSB of college students from other groups, including the transition to increased independence and exposure to new environments, which may facilitate engagement in RSB.^23–25

Many college students report engaging in recent sexual activity.^26–27 Moreover, “hooking up” has become a widespread term used to reference a range of physically intimate activities—from kissing to sexual intercourse—that tend to occur within non-committed relationships.^28–29 The influence of the “hook up” culture during this period may increase exploration in sexual activity among college students, and increase the frequency of certain sexual behaviors, including sex under the influence of substances and casual sex—sexual activity outside of nonromantic and/or noncommitted relationships. Various terms are used to describe forms of casual sexual activity, including one-night stands (e.g., one-time sexual encounters with non-committed partners)³⁰ and friends with benefits (e.g., sexual activity occurring within the context of someone known).^26,31–32 These casual sexual encounters are often unprotected,^{18–19,21–22} increasing students’ risk for negative health outcomes.

The few studies that have examined how PTSD symptoms are linked to RSB in college students suggest positive associations. One study found that trauma-related intrusions associated with child abuse were linked to more frequent casual sex for male and female college students, and to increased impulsive sexual behavior in females.¹⁵ Two additional studies found PTSD symptoms to be positively correlated with various maladaptive coping responses in female college students, including using sex to avoid or distract from distress associated with childhood abuse experiences.^33–34 Finally, in a small sample of African American female college students, PTSD symptoms were linked to a higher number of lifetime sexual partners, lower sexual control (e.g., perceiving control of one’s sexual behaviors), more frequent unprotected vaginal sex, and sex under the influence of substances.³⁵ In sum, preliminary evidence links PTSD symptoms with RSB in college students, but additional research is needed to understand the nature of this relation.

Several possible explanations for the link between PTSD and risky behaviors (including RSB) have been postulated. Individuals with PTSD may engage in RSB in an attempt to reduce or avoid intense negative emotional reactions characteristic of PTSD symptomatology (i.e., tension-reduction).^{14,33,36–37} Conversely, risky behaviors may be used to generate, prolong, or intensify positive affect.^38–39 Personality characteristics, such as impulsivity (i.e., the tendency to act on impulse), have been linked to increased engagement in risk-taking behaviors, including RSB.^40–41 Although multiple definitions of impulsivity exist,⁴² Whiteside and Lynam⁴³ and later Cyders and Smith^44–45 outlined a model of impulsive traits derived from factor analytic studies of existing personality measures of impulsivity. The original model identified four personality traits related to impulsive behavior: 1) sensation seeking—the tendency to seek and relish activities that invoke thrill, 2) urgency—the tendency to experience strong impulses to act rashly in the presence of negative affect, 3) (lack of) premeditation—the tendency to engage in an action before contemplating the consequences of said action, and 4) (lack of) perseverance—the tendency to experience difficulty with being diligent in completing tasks. Cyders and Smith^44–45 later expanded the urgency trait to include 5) urgency in the context of positive affect (i.e., positive urgency).

Most of the research on impulsivity and RSB in college students has focused on the roles of sensation seeking^20,46–48 and negative/positive urgency.^46,49 One study demonstrated that sensation seeking prospectively predicted lifetime engagement in RSB in college students, even after controlling for substance use and other impulsivity facets.⁴⁶ Another cross-sectional study reported a significant positive zero-order relation between sensation seeking and RSB in college students, though sensation seeking did not uniquely predict overall RSB or specific risky sexual acts when the other four impulsivity dispositions were simultaneously entered in the same model.⁴⁹ Importantly, none of these studies considered the influence of trauma exposure or PTSD.

As applied to PTSD symptoms, it has been suggested that sensation seeking may serve as a protective factor following trauma. Former Israeli prisoners of war with high sensation seeking reported a higher threshold for experiencing distress in response to intense and potentially traumatic stimuli and were more likely to use problem-focused active coping strategies to deal with their trauma.⁵⁰ Despite serving as a potential protective factor against initial PTSD development, sensation seeking may still strengthen the relation between PTSD and RSB once PTSD symptoms emerge, as individuals high in sensation seeking tend to be drawn to thrilling activities that may distract from distress (i.e., tension-reduction strategy) or counter the dampening of positive affect seen in PTSD (i.e., prolonging positive affect).^51–52

Several studies have also demonstrated that both negative and positive urgency are linked to more frequent RSB in college students.^{46,48–50,53} However, at least one study suggests relations between urgency and specific types of RSB (i.e., unprotected sex, lamented sexual behavior) may differ for males and females.⁵³ Of note, trauma and PTSD symptoms were also not assessed in these studies. Individuals with PTSD may be more likely to engage in RSB in response to strong negative emotions associated with PTSD if they also tend to engage in rash action in the context of strong negative emotion (i.e., negative urgency).^54–55 Having strong positive urgency in the context of PTSD may be linked to higher engagement in RSB because these behaviors may intensify or prolong positive emotional states in a group of people who are experiencing significant reductions in positive emotions.^54–55

Lastly, both (lack of) premeditation and perseverance have received considerably less focus in understanding RSB. Although several studies have documented positive correlations between (lack of) premeditation and RSB in samples of college students,^{48–49,51,53} findings for (lack of) perseverance have been mixed. One study linked (lack of) perseverance to both later initiation of sexual behavior and fewer sexual partners in college students.⁴⁷ Two other studies demonstrated positive links between (lack of) perseverance and RSB in college students, but the links were nonsignificant when controlling for other impulsive dipositions⁴⁹ or substance use.⁴⁶ None of these studies assessed for trauma history or PTSD symptoms.

Researchers have postulated that (lack of) premeditation may be relevant for RSB because engagement in RSB tends to occur impetuously without much planning or consideration of the possible repercussions. (Lack of) premeditation involves both having a tendency to have low self-restraint⁵⁶ and to engage in spur-of-the-moment action without much forethought.⁴³ As such, (lack of) premeditation may lead individuals to experience increased difficulty with self-control and considering the long-term consequences of RSB, particularly when the RSB is immediately reinforcing.⁵⁷ Theoretical links between (lack of) perseverance and RSB are scarce. In their study of first-year college students, Zapolski, Cyders, and Smith⁴⁸ found a positive relation between (lack of) perseverance and RSB, which primarily included sex without a condom. They hypothesized that individuals high in (lack of) perseverance may find it difficult to be assiduous in obtaining and using condoms consistently, particularly when their partner hesitates to use them.

Though less is known regarding how (lack of) premeditation and perseverance may relate to RSB, certain features of these dispositions may serve to modify the relation between PTSD and RSB. Both of these dispositions reflect low conscientiousness,⁴³ and may lead individuals to experience increased difficulty with self-restraint and with considering and favoring the long-term negative consequences of engaging in RSB (i.e., [lack of] premeditation) or persisting through goal-oriented activities, like insisting on and implementing use of condoms (i.e., [lack of] perseverance). Adults with PTSD have been found to struggle with inhibiting actions that might mitigate their distress in the short-term,⁵⁸ which may be particularly relevant when considering how these two dispositions may further strengthen the relation between PTSD and RSB. These traits may make it difficult to plan for and focus on being safe during sex when the opportunity to engage in RSB seems more immediately satisfying or may reduce their tension rapidly.

To our knowledge, the present study will be the first to evaluate the moderating role of the individual impulsivity dispositions in the relation between PTSD symptoms and RSB in a sample of trauma-exposed college students. A moderation model was hypothesized as impulsivity dispositions are thought to be trait-like personality characteristics that likely precede the development of PTSD. It was hypothesized that individuals high in each disposition would demonstrate a stronger association between PTSD symptoms and RSB. Sensation seeking and negative/positive urgency were expected to have the strongest moderating effects based on prior evidence that they are consistently linked to RSB in a manner consistent with contemporary models of how PTSD symptoms relate to RSB.

Method

Participants

Participants were 221 college-aged adults (Mage = 18.67, SD = 0.95; 77.4% female), recruited from introductory psychology courses, who reported a history of at least one DSM-5 defined Criterion A trauma.¹ The sample was predominantly Caucasian (n = 190; 86.0%), non-Hispanic (n = 210; 94.9%), single (n = 216; 97.7%), and heterosexual (n = 209; 94.6%). Additional racial groups included: African American (n = 16; 7.2%), Asian (n = 3; 1.4%), American Indian or Alaska Native (n = 1; 0.5%), Multi-Racial (n = 7; 3.2%), and Other (n = 4; 1.8%). A minority of participants identified as gay/lesbian (n = 4; 1.8%), bisexual (n = 7; 3.2%), or other (n = 1; 0.5%).

Measures

Trauma exposure.

Participants were asked about exposure to sixteen potentially traumatic events (e.g., natural disasters, serious accidents and injuries, physical or sexual assault, combat exposure) using the Life Events Checklist (LEC-5).⁵⁹ Participants responded to each item indicating whether they had ever experienced each traumatic event either directly, indirectly (witnessed or learned about), or as part of their occupation. They were then asked to select their index traumatic event (i.e., the event they considered to be the worst or most distressing) and indicate when this event occurred, number of times it occurred, and whether it involved life threat, serious injury, death, and/or sexual violence. If the event involved the death of a close loved one, participants were asked to report if the death was due to an accident/violence. Although the psychometric properties of the LEC-5 are still being evaluated, the previous version of the LEC measure exhibited excellent test-retest reliability and good convergent validity with other measures of trauma exposure.⁶⁰

PTSD symptoms.

The PTSD Checklist for DSM-5 (PCL-5)⁶¹ was used to assess past-month PTSD symptom severity in response to the index trauma identified by participants on the LEC-5. Participants indicated the degree to which they were bothered by 20 symptoms of PTSD in the past month using a five-point Likert-type scale (0 = not at all to 4 = extremely). A total score was derived to reflect total PTSD symptom severity with higher scores reflecting greater PTSD symptoms The PCL-5 demonstrates adequate test-retest reliability (r = .82), as well as convergent (rs = .74 to .85) and discriminant validity (rs = .31 to .60)⁶² and has high agreement in diagnosing PTSD with the gold standard Clinician-Administered PTSD Scale (CAPS-5) measure.^63–64 In the present sample, internal consistency was excellent (α = .94). A cut score of ≥ 37 on the PCL-5 demonstrates optimal sensitivity of .66 and specificity of .97 in predicting probable PTSD among college students.⁶² As such, this score was used to determine presence of probable PTSD for descriptive purposes.

Impulsivity.

The 59-item UPPS-P Impulsivity Scale was used to assess personality dispositions that contribute to impulsive behaviors (UPPS-P).⁶⁵ Participants indicated how much they agreed with various examples of impulsive-like attitudes and behaviors. The UPPS-P has five subscales that measure negative urgency (12 items), positive urgency (14 items), sensation seeking (12 items), (lack of) premeditation (11 items), and (lack of) perseverance (10 items). Items were scored on a four-point Likert-type scale (1 = agree strongly to 4 = disagree strongly). The subscale scores were a mean of the items, with higher scores reflecting greater impulsivity. Internal consistency for the subscales in the present sample were acceptable to excellent (α=.78-.95). Scores on the UPPS-P demonstrate good convergent and divergent validity.⁶⁶

Risky sexual behavior.

The frequency of past-year risky sexual acts was assessed using six items from the Risky Behavior Questionnaire (RBQ).⁶⁷ Participants reported the number of times they engaged in the following behaviors: unprotected sex with a non-monogamous partner, one-night stand, sex in exchange for drugs or money, payment for sex using drugs or money, sex with a non-monogamous partner while under the influence of alcohol or drugs, and sex with someone not well-known. The overall RBQ measure has demonstrated strong convergent validity with other measures of risky behavior;⁶⁷ however, this is the first study to specifically utilize the RBQ-sex items. We submitted the six RSB items to a principal components analysis (PCA) with varimax rotation and Kaiser normalization to examine the items’ factor structure. Examination of scree plots and eigenvalues suggested a three-component solution (each with two items) accounting for a total of 92.94% of the total variance. The first component (eigenvalue = 2.12; 35.36% of total variance), labeled “casual sex”, included questions about the frequency of one-night stands (.96) and having sex with someone not known well (.96); Spearman-Brown coefficient = .96. The second component (eigenvalue = 1.80; 29.95% of total variance), labeled “prostitution”, included questions about paying for sex with drugs/money (.98) and having sex in exchange for drugs/money (.90); Spearman-Brown coefficient = .90. The third component (eigenvalue = 1.66; 27.62% of total variance), labeled “high risk sex”, included questions about unprotected sex with a non-monogamous partner (.95) and sex under the influence of alcohol/drugs with a non-monogamous partner (.85); Spearman-Brown coefficient = .80. Items within each scale were summed together to create three composite scores. Due to the infrequent endorsement of RBQ-prostitution, only the RBQ-casual sex and RBQ-high risk sex scales were examined as outcome variables.

Procedure

Participants were enrolled in the study using the SONA System, an online portal aimed at recruiting undergraduate research participants. All students in the subject pool completed the LEC-5⁵⁹ as part of the initial prescreening questionnaire. Students who endorsed experiencing at least one Criterion A trauma were invited to participate in the present study. Eligible participants provided consent and completed the measures for this study, as well as other measures not relevant to the current investigation. Participants received course credit in exchange for participation. Data were collected via Qualtrics. The University of Kentucky’s Institutional Review Board approved all study procedures.

Data Analytic Approach

A series of independent samples t-tests were conducted to examine whether impulsivity facets and PTSD symptom severity scores differed by biological sex (i.e., male/female) and history of sexual trauma (regardless of whether it was identified as the index trauma) as both males and individuals with a history of sexual trauma consistently report higher engagement in RSB.^6,68–70 Degrees of freedom were adjusted for violations of the homogeneity of variance assumption. The RBQ scales were non-normally distributed; the RBQ-high risk sex scale had a skewness of 7.86 (SE = 0.16) and kurtosis of 77.22 (SE = 0.33), and the RBQ-casual sex scale had a skewness of 8.30 (SE = 0.16) and kurtosis of 81.74 (SE = 0.33). These scales were comprised of non-normally distributed count variables, and the composite scores did not conform to a Poisson distribution as determined by the results of the one-sample Kolmogorov-Smirnov Test (p < .01). The RBQ scales had overdispersion and fit the assumptions of the negative binomial regression. To test whether the difference in scores for high risk sex or casual sex varied as a function of biological sex, sexual trauma history, impulsivity dimensions, or PTSD symptoms at the zero-order level, separate negative binomial regression models were conducted.

Two primary models were then evaluated using hierarchical negative binomial regression with high risk sex and casual sex as the outcome in each model; respectively. Covariates of biological sex (0 = male, 1 = female) and sexual trauma history (0 = yes, 1 = no; to aid in interpretation in regression models) were entered into the models to account for their influence on RSB in Step 1. Main effects of each impulsivity disposition and PTSD symptoms were entered into Step 2. Lastly, interactions between each impulsivity disposition and PTSD symptoms were entered into Step 3. This approach allowed us to examine the contribution of each disposition above and beyond the others when predicting the two RSB outcomes. Continuous variables were mean-centered based on the recommendations for testing interactions in negative binomial regression models. Significant interactions were then probed using two-way negative-binomial interaction model plots and simple slopes testing.⁷¹

Results

Descriptive Statistics

Approximately 34.4% (n = 76) of the total sample reported engaging it at least one past-year RSB (endorsing one or more of the six RBQ-sex items), and the average number of RSBs reported by this subsample was 8.51 (SD =12.12). The most commonly reported RSBs were unprotected sex with a non-monogamous partner (23.1%), one-night stand (23.1%), sex with a non-monogamous partner while under the influence of alcohol or drugs (22.6%), and sex with someone not well known (21.7%). Having sex in exchange for drugs or money (1.4%) and paying for sex using drugs or money (0.9%) were endorsed much less frequently. The types of RSBs endorsed in the present study reflect the types of behaviors reported in previous studies of college students.^{18–19,21–22,26,31–32}

Twenty-one percent of study participants endorsed a history of sexual trauma, but only 8.1% of participants identified sexual trauma as their index trauma. The remaining participants reported a diverse range of index traumas including sudden violent or accidental death of a loved one (35.4%), life threatening illness or injury (17.2%), serious accident, fire or explosion (15.4%), natural disaster (6.3%), physical assault (2.7%), military combat or time spent in a war zone (0.9%), captivity (0.5%), or other traumatic experience (13.6%). This distribution of traumatic event types is similar to those reported in prior studies with college student samples.^72–73 Twenty-one participants (9.5%) met criteria for probable PTSD.

A chi-square test of independence determined the relation between biological sex and sexual trauma history was not significant, X²(1, N = 221) = 2.04, p = .15. Zero-order relations among each RSB category, impulsivity disposition, and PTSD symptoms are displayed in Table 1, and tests of RSB category frequency by biological sex and sexual trauma history are displayed in Tables 2–3. As displayed in Table 1, PTSD symptoms were positively related to the frequency of both high risk and casual sex. All the impulsivity dispositions were positively related to frequency of casual sex. Each dimension, except for (lack of) premeditation, was also positively associated with frequency of high risk sex. As displayed in Table 2, males in the study reported a higher number of both types of RSB and greater scores on sensation seeking in comparison to females, while females displayed more severe PTSD symptoms. Participants with sexual trauma histories reported more frequent casual sex and higher scores for PTSD symptom severity, negative urgency, (lack of) premeditation and (lack of) perseverance compared to those without sexual trauma histories (Table 3).

Table 1.

Zero-Order Associations Between Impulsivity Dimensions/PTSD Symptoms and High Risk/Casual Sex

	High risk sex					Casual sex
	B	SE	Wald χ2	IRR	95% CI	B	SE	Wald χ2	IRR	95% CI
Sensation seeking	0.61	0.16	14.50***	1.85	1.35 – 2.53	0.89	0.16	29.84***	2.43	1.77 – 3.34
Negative urgency	0.39	0.15	6.82**	1.48	1.10 – 1.98	1.49	0.20	55.00***	4.43	2.99 – 6.57
Positive urgency	1.09	0.16	47.51***	2.97	2.18 – 4.06	1.22	0.16	55.62***	3.37	2.45 – 4.65
(Lack of) premeditation	0.16	0.20	0.69	1.18	0.80 – 1.74	1.52	0.25	37.92***	4.57	2.82 – 7.40
(Lack of) perseverance	0.55	0.24	5.29*	1.73	1.49 – 2.08	0.59	0.27	4.97*	1.81	1.07 – 3.05
PTSD symptoms	0.01	0.01	3.92*	1.01	1.00 – 1.02	0.04	0.01	40.09***	1.04	1.03 – 1.06

Note.

^*p < .05

^**p < .01

^***p < .001; CI = Confidence interval; IRR = Incidence rate ratios; PTSD = Posttraumatic stress disorder; SE = Standard error.

Table 2.

High Risk and Casual Sex, Individual Impulsivity Dispositions, and PTSD Symptoms by Biological Sex

	Overall		Females		Males
	M	SD	M	SD	M	SD	t	B	SE	Wald χ2	IRR	95% CI
High risk sex	1.80	6.12	1.20	3.07	3.84	11.40	--	1.16	0.19	37.71***	3.20	2.21 – 4.64
Casual sex	1.11	3.88	0.97	2.77	1.92	6.33	--	0.79	0.21	14.52***	2.20	1.47 – 3.31
Sensation seeking	2.85	0.60	2.79	0.61	3.09	0.53	3.24**	--	--	--	--	--
Negative urgency	2.32	0.56	2.34	0.56	2.24	0.57	−1.13	--	--	--	--	--
Positive urgency	2.01	0.65	1.98	0.66	2.11	0.60	1.24	--	--	--	--	--
(Lack of) premeditation	2.03	0.42	2.02	0.43	2.08	0.38	0.94	--	--	--	--	--
(Lack of) perseverance	1.95	0.42	1.95	0.43	1.95	0.40	−0.09	--	--	--	--	--
PTSD symptoms	13.67	14.08	14.59	14.72	10.52	11.24	−2.09*	--	--	--	--	--

Note.

^*p < .05

^**p < .01

^***p < .001; CI = Confidence interval; IRR = Incidence rate ratios; PTSD = Posttraumatic stress disorder; SD = Standard deviation; SE = Standard error.

Table 3.

High Risk and Casual Sex, Individual Impulsivity Dispositions, and PTSD Symptoms by Report of Any Sexual Trauma

	Overall		Any Sexual Trauma
			Yes		No
	M	SD	M	SD	M	SD	t	B	SE	Wald χ2	IRR	95% CI
High risk sex	1.80	6.12	2.13	4.40	1.71	6.52	--	0.22	0.20	1.20	1.25	0.84 – 1.85
Casual sex	1.11	3.88	2.71	7.74	0.68	1.52	--	−0.39	0.21	44.06***	3.98	2.65 – 5.99
Sensation seeking	2.85	0.60	2.80	0.70	2.87	0.57	−0.75	--	--	--	--	--
Negative urgency	2.32	0.56	2.52	0.55	2.27	0.56	2.75**	--	--	--	--	--
Positive urgency	2.01	0.65	2.16	0.66	1.97	0.64	1.75	--	--	--	--	--
(Lack of) premeditation	2.03	0.42	2.17	0.49	1.99	0.39	2.28*	--	--	--	--	--
(Lack of) perseverance	1.95	0.42	2.07	0.44	1.92	0.41	2.17*	--	--	--	--	--
PTSD symptoms	13.67	14.08	22.96	15.12	11.16	12.71	4.90***	--	--	--	--	--

Note.

^*p < .05

^**p < .01

^***p < .001; CI = Confidence interval; IRR = Incidence rate ratios; M = Mean; PTSD = Posttraumatic stress disorder; SD = Standard deviation; SE = Standard error.

Primary Models

High risk sex.

Results from the hierarchical negative binomial regression model examining predictors of high risk sex are displayed in Table 4. After controlling for positive associations with male sex and sexual trauma history, significant interactions for some impulsivity dispositions by PTSD symptoms emerged, specifically for negative urgency, positive urgency, (lack of) premeditation, and (lack of) perseverance. Though the interaction between sensation seeking and PTSD symptoms was not significant, there was a significant positive main effect of sensation seeking. Post-hoc probing of the negative urgency (Figure 1) and (lack of) premeditation (Figure 3) by PTSD interactions demonstrated that, consistent with hypotheses, the positive relation between PTSD symptoms and high risk sex was only significant for individuals high in these dispositions. Post-hoc probing of the positive urgency (Figure 2) and (lack of) perseverance (Figure 4) by PTSD symptoms interactions demonstrated a different—and unexpected—pattern. Specifically, individuals high in positive urgency or (lack of) perseverance reported more frequent high risk sex, regardless of PTSD symptom severity. For people low in positive urgency or (lack of) perseverance, the frequency of high risk sex increased as PTSD symptoms increased.

Table 4.

Interactions between PTSD Symptom Severity and Individual Impulsivity Dispositions Predicting Frequency of High Risk Sexual Activity.

	Omnibus Test - Step
Models	χ2	p	B	SE	Wald χ2	IRR	95% CI
Step 1 - Covariates	49.39	<.001
Male			1.31	0.20	43.86***	3.69	2.51 – 5.43
Sexual trauma history			0.60	0.21	7.94**	1.82	1.20 – 2.77
Step 2 - Main Effects	50.85	<.001
Sensation seeking			0.40	0.19	4.65*	1.50	1.04 – 2.16
Negative urgency			−0.74	0.29	6.45*	0.48	0.27 – 0.85
Positive urgency			1.28	0.26	23.99***	3.61	2.16 – 6.04
(Lack of) premeditation			−0.24	0.29	0.68	0.79	0.44 – 1.39
(Lack of) perseverance			0.45	0.32	2.01	1.57	0.84 – 2.91
PTSD symptoms			0.25	0.01	8.85**	1.03	1.01 – 1.04
Step 3 - Interactions	45.32	<.001
Sensation seeking x PTSD symptoms			−0.02	0.02	1.38	0.98	0.96 – 1.01
Negative urgency x PTSD symptoms			0.09	0.03	11.54**	1.09	1.04 – 1.14
Positive urgency x PTSD symptoms			−0.07	0.02	12.40***	0.94	0.90 – 0.97
(Lack of) premeditation x PTSD symptoms			0.10	0.02	17.72***	1.10	1.05 – 1.15
(Lack of) perseverance x PTSD Symptoms			−0.07	0.02	7.92**	0.94	0.89 – 0.98

Note.

^*p < .05

^**p < .01

^***p < .001; PTSD = Posttraumatic stress disorder; SE = Standard Error; IRR = Incidence Rate Ratios; CI = Confidence Interval.

Figure 1.

Interaction Between Negative Urgency and Posttraumatic Stress Disorder (PTSD) Symptom Severity on Frequency of High Risk Sexual Acts

Figure 3.

Interaction Between (Lack of) Premeditation and Posttraumatic Stress Disorder (PTSD) Symptom Severity on Frequency of High Risk Sexual Acts

Figure 2.

Interaction Between Positive Urgency and Posttraumatic Stress Disorder (PTSD) Symptom Severity on Frequency of High Risk Sexual Acts

Figure 4.

Interaction Between (Lack of) Perseverance and Posttraumatic Stress Disorder (PTSD) Symptom Severity on Frequency of High Risk Sexual Acts

Casual sex.

Results from the hierarchical negative binomial regression model examining predictors of casual sex are displayed in Table 5. After controlling for positive associations with male sex and sexual trauma history, significant positive main effects emerged for negative urgency and (lack of) premeditation. The effect of PTSD symptoms and other impulsivity dimensions were not significant and there were no significant interactions.

Table 5.

Interactions between PTSD Symptom Severity and Individual Impulsivity Dispositions Predicting Frequency of Casual Sexual Activity.

	Omnibus Test - Step
Models	χ2	p	B	SE	Wald χ2	IRR	95% CI
Step 1 - Covariates	63.08	<.001
Male			0.84	0.22	14.80***	2.32	1.51 – 3.56
Sexual trauma history			1.41	0.21	44.19***	4.10	2.70 – 6.21
Step 2 - Main Effects	60.75	<.001
Sensation seeking			0.30	0.22	1.77	1.35	0.87 – 2.09
Negative urgency			0.69	0.34	4.10*	2.00	1.02 – 3.91
Positive urgency			0.38	0.27	1.97	1.47	0.86 – 2.50
(Lack of) premeditation			1.16	0.34	11.62***	3.18	1.64 – 6.19
(Lack of) perseverance			−0.16	0.39	0.17	0.85	039 – 1.84
PTSD symptoms			0.01	0.01	0.98	1.01	0.99 – 1.03
Step 3 - Interactions	7.55	.18
Sensation seeking x PTSD symptoms			0.23	0.02	2.25	1.02	0.99 – 1.05
Negative urgency x PTSD symptoms			0.04	0.03	2.08	1.04	0.99 – 1.10
Positive urgency x PTSD symptoms			−0.03	0.02	2.06	0.97	0.94 – 1.01
(Lack of) premeditation x PTSD symptoms			0.02	0.02	0.96	1.02	0.98 – 1.07
(Lack of) perseverance x PTSD Symptoms			−0.02	0.03	0.35	0.98	0.93 – 1.04

Note.

^*p < .05

^**p < .01

^***p < .001; PTSD = Posttraumatic stress disorder; SE = Standard Error; IRR = Incidence Rate Ratios; CI = Confidence Interval.

Discussion

PTSD symptoms have been linked to RSB across various samples,^{5,12, 16,74} including college students.¹⁵ A number of developmental and environmental factors differentiate RSB in college students from other groups, including their increased freedom due to the transition of living independently^23–25 and the influence of the “hook up” culture among students.²⁹ Although a link between PTSD and RSB has been established, the exact nature of this relation is not fully understood. Therefore, the present study examined the moderating role of five impulsivity dispositions in the relation between PTSD symptoms and two categories of RSB—high risk and casual sex—in a sample of trauma-exposed college students.

Consistent with previous studies, male participants were higher in sensation seeking^75–76 and engaged in more frequent RSB than female participants;^68–69 while female participants reported more severe PTSD symptoms.^77–78 Prior studies have documented discrepancies in report of RSB by gender, with women being more likely to underreport⁷⁹ and men tending to overreport their RSB.⁸⁰ Both gender and societal norms governing sexuality may impact accurate reporting of RSB by gender, and thus, these findings should be interpreted with caution. Though prior studies have found that women are more likely to experience sexual trauma than men,⁸¹ the prevalence of sexual trauma did not significantly differ by biological sex in the present study. However, the fact that our participants were all trauma exposed and predominantly female may have biased these findings. Lack of differences in sexual trauma history could have also resulted from how we defined sexual trauma, which included varying forms of unwanted sexual experiences, like penetrative rape and other unwanted sexual experiences (e.g., touching private parts). Adopting this broader definition allowed us to capture more diverse unwanted sexual experiences; a notable strength. However, this approach may have, in turn, suppressed sex differences that may have emerged in terms of more invasive forms of sexual trauma (e.g., penetrative rape).

Similar to previous studies, having a sexual trauma history was associated with more frequent engagement in casual sex^70,82 and higher PTSD symptom severity.^81–82 There were no significant differences in engagement in high risk sex based on sexual trauma history. Due to the low number of participants with sexual trauma-related PTSD symptoms (8.1% of total participants), we were unable to test the primary models solely among participants with sexual trauma-related PTSD symptoms or compare whether the relation between PTSD symptoms and the two RSB categories differed by trauma type (i.e., sexual vs. other trauma).

Interestingly, participants with sexual trauma histories reported higher negative urgency, (lack of) premeditation, and (lack of) perseverance scores in comparison to those without sexual trauma history. Given the cross-sectional nature of this study, it was not possible to disentangle the nature of the relation. Potentially, individuals who are higher in these dispositions may be at greater risk for experiencing sexual trauma than those who are lower. It could also be sexual trauma may lead to increases in these dispositions. Additionally, there may be unmeasured biological or environmental factors that may both increase risk for sexual trauma and lead to higher expression of these dispositions. Longitudinal studies are needed to further investigate the directionality of these relations.

Biological sex was included as a covariate in the analyses in order to account for sex differences in both engagement in RSB and PTSD symptom severity. The limited number of male participants in the present study precluded our ability to conduct sex-specific analyses. Future studies with more male participants—particularly those with a history of sexual trauma—are needed in order to understand the unique impact of biological sex and sexual trauma history on students’ RSB engagement, PTSD symptom severity and impulsivity.

In line with prior findings, PTSD symptom severity was associated with more frequent engagement in both high risk and casual sex.^15,33–35 Also in line with previous findings establishing relations between individual impulsivity dispositions and RSB,^{20,46–49,50,55} we found positive relations between each of the impulsivity dispositions and casual sex at the zero-order level. Each of the impulsivity dispositions except for (lack of) premeditation, were also positively associated with high risk sex.

Counter to expectations, the interaction between PTSD symptoms and sensation seeking did not predict engagement in high risk sex. Instead, both sensation seeking and PTSD symptom severity were independently positively related to engagement in high risk sex, even after accounting for biological sex, sexual trauma history, and the other four impulsivity dimensions. It may be that an additive model for sensation seeking and PTSD symptoms is most relevant in predicting high risk sexual behavior, but further exploration is needed. Though there was strong theoretical support to suggest an interaction between PTSD symptoms and sensation seeking, our predominantly female sample may explain this nonsignificant finding, since sensation seeking tends to be more relevant for males.^75–76 Futures studies should recruit larger samples with comparable numbers of females and males to allow for sex-specific analyses.

Significant interactions between PTSD symptoms and the other four impulsivity dispositions did emerge; however, the relation patterns differed as a function of the type of disposition. As PTSD symptom severity increased, engagement in high risk sex increased as predicted among individuals high in negative urgency and high in (lack of) premeditation. With regard to negative urgency, findings support the theory that as distress associated with PTSD symptoms increase, individuals who are at heightened risk for acting impulsively in response to strong negative affect may be more likely to impulsively engage in high risk sex as a means to mitigate/avoid strong negative emotion.^{33–34,36–37} Interestingly, PTSD symptoms were not associated with engagement in high risk sex in individuals with low negative urgency, highlighting the importance of this moderator in understanding the association.

PTSD symptom severity was also positively linked to high risk sex among individuals high in (lack of) premeditation, which is notable since this disposition has received little theoretical attention in relation to RSB. Among students high in (lack of) premeditation, PTSD symptoms—which are associated with trouble inhibiting behavior that may mitigate distress^58—may lead to favoring the short-term benefits of actions associated with impulsive or unplanned high risk sexual activity (i.e., reduction in negative emotions or increase or initiation/protraction of positive emotions) over the possible negative consequences of these behaviors, though further exploration of this association is needed.

Counter to expectations, PTSD symptom severity was not associated with frequency of high risk sex among individuals high in either positive urgency or (lack of) perseverance. Instead, PTSD symptoms were positively related to high risk sex only among individuals who were low in these impulsivity traits. This pattern was unexpected, and further examination of the data suggested that participants who were high in positive urgency or (lack of) perseverance engaged in more frequent high risk sex regardless of the intensity of their PTSD symptoms, suggesting that—in the presence of high levels of these impulsive dispositions—PTSD symptoms may not contribute additional risk for engagement in high risk sex. In contrast, for individuals low in these impulsive dispositions, we see the expected positive relationship between PTSD symptoms and high risk sex. These findings converge with those of previous studies highlighting the importance of positive urgency^44–45 for understanding overall RSB as well as specific risky sexual acts.^46,48–49 Prior findings for (lack of) perseverance have been more mixed,^47–49 and this work suggests that it may be important to further consider the role of (lack of) perseverance in college students, particularly as it relates to predicting unprotected sex and sex under the influence of alcohol and drugs.

After accounting for biological sex, sexual trauma history, and the other impulsivity facets, only negative urgency and (lack of) premeditation were positively related to frequency of casual sex. None of the other impulsivity dispositions, PTSD symptoms, nor any of the interactions were significantly related to casual sex when considered together. Differences in findings between the casual sex and high risk sex models may be a function of the types of behaviors each outcome assessed. The high risk sex variable was comprised of riskier behaviors (i.e., unprotected sex with a non-monogamous partner, sex under the influence with a non-monogamous partner), whereas the behaviors included in the casual sex variable (i.e., one night stands; sex with someone not well known) may constitute more developmentally normative sexual behavior among college students. Though it is possible that the unique contribution of PTSD symptoms is to increase risk for engaging in impulsive, high risk sexual behaviors; the RBQ-casual sex items did not specify whether these sex acts involved the use of protection or occurred while under the influence of alcohol or drugs. Future studies should assess sexual activities in more refined detail to determine what types of RSB both PTSD symptoms and impulsivity dispositions predict among college students.

Although our findings may be consistent with the theory that RSB serves as an emotion regulation strategy to diffuse or avoid negative emotions and/or to elicit/prolong positive emotions, future studies with designs more ideally suited to evaluate this theory directly are needed. Future studies should consider assessing the context in which RSB occurs (e.g., when experiencing positive affect vs. negative affect/distress), individual expectancies regarding the function of RSB, and self-reported motives for engaging in RSB.

Limitations for this study include use of cross-sectional data, which precludes conclusions regarding temporal or causal relationships among the constructs investigated in this study. Prospective data are needed to determine whether PTSD symptoms and specific impulsivity dispositions operate in an additive or interactive way to prospectively predict increased engagement in RSB in trauma-exposed college students. Moreover, although the present investigation tested a moderating model of impulsive personality traits on the relationship between PTSD symptoms and RSB, it is also possible that individuals high in impulsivity (or certain impulsivity dispositions) may be more likely to develop symptoms of PTSD, which may in turn lead to increased engagement in RSB. It is also possible that traumatic events, including sexual trauma, or the presence of PTSD symptoms (especially chronic symptoms) may lead to increases in impulsive personality traits over time. A priori power analysis was not conducted for the present study given that it is a secondary data analysis. We may have been underpowered to detect small effects, and thus, the specificity of the findings should be interpreted with caution. It is possible that the non-significant effects may have not detected due to low power.

Additional limitations included reliance on self-report, including retrospective self-report of past-year engagement in RSB. Use of methods such as daily diary tracking may capture a more valid measurement of participants’ sexual behavior by reducing potential for recall biases that occur when assessing behavior over long periods.^83–85 Additionally, the present study was the first to use the six sex items of the RBQ to assess RSB. Psychometric analyses suggested that these items measure three separate domains of RSB among college students, one of which—prostitution—was endorsed very infrequently. Moreover, the use of 2-item scales is discouraged due to psychometric limitations,⁸⁶ and future studies should consider utilizing measures specifically developed to assess RSB in college students. Future studies may also consider using the entire RBQ measure in order to determine whether these effects are specific to RSB or are related to risky behavior broadly. Given the documented symptom overlap between PTSD and depression,⁸⁷ future studies may consider controlling for depression. Social desirability bias (e.g., the tendency to respond to items in a socially acceptable manner)⁸⁸ may have impacted participants RSB reports by biological sex, such that participants may have responded in a manner that seemed socially appropriate for their sex. Some UPPS-P items are framed in when-then sequences and there is evidence to suggest that respondents may have difficulty accurately recalling and reporting their behavior when items are worded in this manner.⁸⁹ Future research should further consider use of a PTSD interview measure, such as the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5),⁹⁰ though, the PCL-5 and the CAPS-5 have demonstrated comparable diagnostic performance.^64,91 The present study also did not examine the impact of alcohol or other substance use, other than to inquire about sexual behavior while under the influence of alcohol or drugs. Investigating the specific role of alcohol and other substance use in these relationships is critical for future studies given that college students engage in high rates of alcohol and illicit drug use (particularly marijuana use), and substance use has been strongly linked to impulsivity, increased engagement in RSB and PTSD symptoms.^92–97

Due to the low rate of probable PTSD in this sample, our results may not generalize to students with more severe PTSD presentations. The most commonly reported RSBs in the present sample were unprotected sex with a non-monogamous partner, one-night stands, sex under the influence of alcohol/drugs, and sex with someone not well-known. Our study findings may not generalize to other groups who engage in other types of RSB (e.g., sex in exchange for drugs or money). Lastly, our sample was predominantly Caucasian, non-Hispanic and heterosexual, which affects the generalizability to other racially and ethnically or LGBTQ+ groups, and thus future studies should recruit more diverse samples.

Clinical implications.

Several potential intervention strategies could be used to reduce RSB in college students. Interventions that target PTSD symptoms may reduce reliance on RSB to mitigate negative affect or prolong positive affect.⁹⁸ For both negative and positive urgency, strategies focused on managing and coping with strong emotions, like emotion regulation and distress tolerance skills, and identifying possible warning signs for emotion-driven impulsive behaviors may reduce RSB.⁹⁹ For (lack of) premeditation, helping students identify both the positive and negative outcomes of their actions, can help them slow down and consider the possible consequences of their RSB before proceeding.^99–100 For (lack of) perseverance, it may be helpful to have students identify and complete all the necessary steps to engage in safe sex (i.e., from obtaining to ultimately using condoms) using some behavioral reinforcement.⁹⁹ In the context of sensation seeking, helping college students identify other safe behaviors that are thrilling and appealing may offer alternatives to RSB.¹⁰¹

Conclusion

Despite limitations, results from the present study extend the current body of research regarding the relation between PTSD symptoms and RSB among college students by testing whether individual impulsivity dispositions moderate this relation. Results support the finding that PTSD symptoms and impulsivity dispositions are positively related to RSB, but these relations differ when predicting high risk versus casual sex behaviors. This was the first study to suggest the link between PTSD symptoms and RSB may be stronger among individuals high in negative urgency and (lack of) premeditation. Given that RSB is associated with negative health outcomes and risk for additional trauma, continued elucidation of the factors and processes involved in predicting RSB in college students and other populations is clearly needed.