# Presentation: 219466

## Impact of Hurricane Katrina on Gulf Coast veterans with and without pre-existing mental illness.

- Principal Investigator: Joseph Constans, Ph.D.
- Co-Investigators:
- 			Greer Sullivan, M.D.
- 			Jennifer Vasterling, Ph.D.
- Project Director: Elizabeth Deitch, Ph.D.
- VA Database managers:
- 			Teresa Hudson, PharmD
- 			James S. Williams
- Survey Development and Administration Consultant:
- 			Dana Perry, M.S.

## Hurricane Katrina

- Massive size; devastated Gulf Coast up to 100 miles from storm center.

## Hurricane Katrina

- One of the costliest and most destructive hurricanes in U.S. history.

**Gulfport, MS**

## Hurricane Katrina

- Over half of New Orleans flooded when levees breached.

## Hurricane Katrina

- Approximately 1720 people died in storm and aftermath.

## Psychological Stressors of Hurricane Katrina

- Fear for life of self & others
- From storm itself, floodwaters, hunger, thirst
- Fear of crime and violence
- Looting, assaults, breakdowns of civil authority
- Loss of belongings
- Basic necessities, sentimental items
- Loss of support system
- Neighborhoods & families split up in evacuation or rescue
- Uncertainty & Ambiguity
- N.O. evacuation stretched to a month; status of homes, jobs, friends/family/pets uncertain.

## Impact of Natural Disasterson Health

- Review of research shows disasters lead to:
- Increased general distress
- Increased incidence of psychiatric disturbance
- Poorer physical health outcomes
- 				(Norris, Friedman & Watson, 2002)
- Most common psychiatric illnesses after disaster: PTSD, generalized anxiety disorder, major depression, panic disorder
- 				(David, et al., 1996)

## Current Study Aims

- Study Aim 1: To determine whether veterans with a psychiatric disorder prior to Hurricane Katrina are at increased risk of additional negative mental health outcomes
- Pre-existing mental illness (PMI) is a risk factor for developing new-onset disorders after natural disaster (Norris & Elrod, 2006).
- Veterans have not been specifically studied.
- It is unclear how veterans, especially those with combat stress, will react to disasters.

## Current Study Aims

- Study Aim 2: To determine whether individuals with pre-Katrina mental illness have fewer social support resources and appraise their response to the hurricane and its aftermath more negatively than veterans without PMI.
- Lack of social support & negative cognitive appraisals are additional risk factors for post-disaster mental illness (see review by Norris et al, 2002)
- PMI may be associated with these risk factors, contributing to negative outcomes.

## Current Study Aims

- Study Aim 3: To examine the relative impact of various risk factors and determine if predictors of post-disaster health outcomes are similar for veterans with and without PMI.
- Exploratory. Predictors of interest include:
- Demographic: race, education
- Financial resources
- Severity of exposure to hurricane stressors (location on day of Katrina, damage to property, & traumatic events)
- Reactions to hurricane stressors (emotions experienced, changes in how one views the world and other people)
- Social support
- Cognitive appraisals

## Overview of Study Design

- Telephone survey
- experiences during & after Katrina
- Loss, social support, cognitive factors
- Current health / mental health functioning
- Administered by professional survey firm.
- Target: 500 participants
- 250 with pre-existing mental illness
- 250 with no PMI.

## Participants

- 500 male veterans aged 18-60 as of 8/29/05
- Received services at N.O. or Biloxi VAMC.
- Resided in affected area at time of Katrina:
- LA parishes: Jefferson, Orleans, Plaquemines, St. Tammany, St. Bernard
- MS counties: Hancock, Harrison, Jackson
- MI positive cohort (n=250)
- 1+ visits to mental health clinic between 8/1/04-8/1/05
- Diagnosis of depression, PTSD, or psychotic disorder
- MI negative cohort (n=250)
- 1+ visits to primary care clinic between 8/1/04-8/1/05
- No mental illness diagnoses

## Geographic Eligibility
Participants with pre-Katrina residence in a zip code at least 50% in one of the following:
 Orleans Parish
 Jefferson Parish
 Plaquemines Parish
 St. Tammany Parish
 St. Bernard Parish
 Hancock County
 Harrison County
 Jackson County

- Participants with pre-Katrina residence in a zip code at least 50% in one of the following:
-  Orleans Parish
-  Jefferson Parish
-  Plaquemines Parish
-  St. Tammany Parish
-  St. Bernard Parish
-  Hancock County
-  Harrison County
-  Jackson County

## Survey Measures

- Demographic information
- Employment
- Income
- Military history
- Household information
- Katrina traumatic events
- Damage to property
- Feelings during Katrina
- Changes in worldview

- Hope for future
- Cognitive appraisals
- Perceived social support
- Post-traumatic stress disorder
- Generalized anxiety disorder
- Panic disorder
- Depression

## Preliminary Results

- 352 interviews completed
- 168 MI–
- 184 MI+ with the following pre-Katrina diagnoses:
- 108 (58.7%) PTSD
- 71 (39.7%)	  Depression
- 1 (0.5%)	  Panic
- 7 (3.8%)	  GAD
- 11 (6.0%)	  Bipolar
- 15 (4.3%)	  Schizophrenia

## Demographics

- Mean age = 53.7, median = 57
- MI– group slightly younger (mean age=52.2, vs. 55 for MI+)
- Race: 42% Black, 50% White, 8% Other/Mixed (no difference between groups)
- 66% married or living with someone as if married (no difference between groups)
- Education:
- 	96% graduated from high school
- 	67% have vocational education or some college 21% have college degrees
- 	7% have advanced degrees
- 	(no difference between groups)

## Demographics

- Income:
- Pre-Katrina, median category: $30,000 - $34,999
- 	(no difference between groups)
- Post-Katrina, median category: $25,000 - $29,999
- 	(no difference between groups)
- Employment – significant difference between groups:
- 41% of MI+ group, 66% of MI- group employed pre-Katrina
- 35% of MI+ group, 62% of MI- group employed currently
- 45 individuals (21 MI+ and 24 MI-) report having lost a job since Katrina.  However, most have found other jobs; only 18 people who were employed pre-Katrina are unemployed now.  Eight respondents who were not employed pre-Katrina are working currently.
- 26 respondents said they make less money now than before Katrina, but 20 reported they earn more at their job currently.

## Military History

- Branch of service:
- 47% Army; 20% Navy, 15% marines, 14% Air Forces, 2% Coast Guard, 2% National Guard
- 80% of the Marines are in the MI+ group.
- Other branches are more evenly distributed between the groups.
- Combat zone service: 74% of MI+ group and 49% the MI– group served in a combat zone
- Combat Locations:
- 68% of Vietnam vets are in the MI+ group.
- 83% of OIF vets are in MI– group.
- Other locations and those in 2 combat zones are roughly equal between the groups.
- 5 people report serving in 3 combat zones; 4 of those are in MI+ group.

## Geographic Location

## No group differences in geographic distribution

## 64% remained in area on day of Katrina

## 24% are still living outside the area today

## Damage & Losses

- No differences between groups
- Type of damage:
- 97% reported physical damage to structures on the property where they lived
- 57% reported damage to car, truck or boat
- 84% reported damage to items inside their home
- 68% reported the loss of sentimental items
- Median dollar estimate of total losses = $30,000
- Median estimated payments from insurance and grants = $12,000
- 82% reported losses exceeding payments; median shortfall = $10,000

## Traumatic events during Katrina

| Event | % all | % MI+ | % MI– |   Comparison     |
| --- | --- | --- | --- | --- |
| 1.   Thought you were going to die | 29 | 35 | 23 | Χ2 = 6.14, p <.05 |
| 2.   Were seriously injured or became ill | 33 | 43 | 22 | Χ2 = 16.68, p <.001 |
| 3.   Saw, in person, dead body(-ies)  | 30 | 35 | 24 | Χ2 = 4.67, p <.05 |
| 4.   Personally witnessed someone die | 13 | 15 | 10 | ns |
| 5.   Family member/close friend died | 34 | 38 | 30 | ns |
| 6.   Family member/close friend ill or injured | 39 | 46 | 30 | Χ2 = 8.65, p <.01 |
| 7.   Pets died or left behind and lost | 17 | 19 | 15 | ns |
| 8.   Had things stolen from you | 34 | 35 | 32 | ns |
| 9.   Family/close friends had things stolen | 57 | 59 | 54 | ns |
| 10. Otherwise victimized (e.g., physical/ sexual assault, armed robbery) | 8 | 11 | 5 | Χ2 = 4.74, p <.05 |
| 11.  Family/close friends otherwise victimized | 20 | 20 | 20 | ns |

## Hypothesis tests

_*Hypothesis 1*_*: Veterans with pre-Katrina mental disorders will show significantly higher rates of new-onset posttraumatic stress disorder (PTSD), depression, panic disorder (PD), and generalized anxiety disorder (GAD), as compared with veterans without evidence of pre-existing mental disorders.*
- H1 is supported for panic disorder:
- New onset PD:	MI+ group (n=183):	39.3%
- 		MI- group (n=168): 	8.3%
- 		Χ2 = 45.5, *p* <.001
- H1 is supported for generalized anxiety disorder:
- New onset GAD:	MI+ group (n=177): 	57.1%
- 		MI- group (n=168): 	19.6%
- 		Χ2 = 50.8, *p* <.001

**Notes:**
People who had a previous diagnosis of the disorder were excluded (thus the varying n for the MI+ group). There were few with PMI diagnoses for these disorders: 1 PMI Panic diagnosis and 7 GAD.
Cut scores: 	
For Panic (5-item scale from Brief Patient Health Questionnaire), need 5 out of possible 5 (symptom endorsement) for diagnosis of disorder.
For GAD, cut is 10 (out of possible 21), which is cut with maximum predictive efficiency according to original Spitzer 2006 article about the GAD7 measure

## Hypothesis tests

- It is not clear how “new onset” PTSD should be defined.  Items referenced Katrina-related trauma, so all Katrina-related PTSD could be considered “new.” Alternatively, only individuals without previous PTSD could be considered “new.”  H1 is supported with either analysis:
- If all considered new:
- Current PTSD:	MI+ group (n=184): 	67.9%
- 		MI- group (n=168): 	25.0%
- 		Χ2 = 64.9, *p* <.001
- Analyzing only those without PMI PTSD
- New onset PTSD:	MI+ group (n=76): 	57.9%
- 		MI- group (n=168): 	25.0%
- 		Χ2 = 24.8, *p* <.001

**Notes:**
This uses the cut score of 14 on SPRINT (recommended cut for general population), on scale with possible scores 0-32.  

## Hypothesis tests

- H1 appears supported with regard to depression.
- Examining those with no PMI diagnosis of depression:
- New Depression:	MI+ group (n=111): 	53.2%
- 		MI- group (n=168): 	13.7%
- 		Χ2 = 50.2, *p* <.001
- A limitation here: a PTSD diagnosis can include depression, without a separate explicit depression diagnosis being recorded.

**Notes:**
Using cut of 4 (out of possible 6) on PHQ-2.

## Hypothesis tests

_*Hypothesis 2a*_*:  Veterans with pre-Katrina mental illness will report lower levels of social support than veterans without pre-Katrina mental illness.*
- H2a is supported.
- Perceived Social Support (range: 1-4):
- 	MI+ mean = 2.73 (*SD *= .81)
- 	MI- mean = 3.27 (*SD *= .68)
*	**t* = 6.75, *p* <.001

**Notes:**
Social support scale scores are mean of 9 items, range is 1 – 4, higher scores = more support.

## Hypothesis tests

_*Hypothesis 2b*_*: Veterans with pre-Katrina mental illness will engage in more negative cognitive appraisals of the impact of the hurricane and their actions and emotions in response to it, than will veterans without pre-Katrina mental illness.*
- H2b is supported.
- Negative Cognitions score (range: 1-5):
- 	MI+ mean = 2.43 (*SD *= 1.12)
- 	MI- mean = 1.55 (*SD *= .70)
*	**t* = 8.93,  *p* <.001

**Notes:**
Negative cognitions is mean of 15 items, range 1 – 5, higher scores = more negative cognitions.

## Mediation?

- Group differences in mental health outcomes may be mediated through social support and cognitions.
- Social support is a resource which may help protect against the development of mental illness.
- Negative cognitive appraisals of oneself and one’s situation may make the development of new mental illness more likely.
- Regression analyses using continuous scores on outcome measures suggest partial mediation.

**Notes:**
This is how the analysis goes for each DV, on the following four slides.  These are using the continuous outcome scores, not dichotomous diagnoses:
- We see that zero-order correlations between group, negative cognitions, social support, and outcomes are all significant.  Group is correlated with the outcome, and the MI+ people do have significantly lower social support and more negative cognitions
- Enter PMI diagnosis of disorder as control in first step.  When mental health outcome scores are regressed on social support, cognitions, and the ss x cog interaction, that explains nearly all the variance in the outcome scores.  Partial correlation of group with DV (controlling for social support and cognitions) is considerably smaller.
- However, a small but significant amount of additional variance is still explained by group membership. 

## DV: Depression score
Correlations:
  		                             Depression	Group	Soc Sup
	Group (MI+:1, MI-:2)	-.49**	
	Social Support	-.52**	  	.34**
	Negative Cognitions	 .69**	 	-.42**	   -.54**

Regression
	Block	Predictors		   β		   p	  	 ΔR2
	   1	PMI diag: Depression	 .176		<.01	 	.031
	   2	Social support		-.361		<.001		.499
		Negative cognitions		 .214		 [.08]
		Soc sup X Neg cog		 .268		<.05
    	   3	Group		-.212		<.001		.027
						Total R2 =	.558
Remaining partial correlation of Group with Depression = -.24 (p<.001)

- _Correlations:_
-   		                             Depression	Group	Soc Sup
- 	Group (MI+:1, MI-:2)	-.49**
- 	Social Support	-.52**	  	.34**
- 	Negative Cognitions	 .69**	 	-.42**	   -.54**
- _Regression_
- 	_Block__	__Predictors__	__	__   __β__	__	__   p__	__  __	__ __Δ__R__2_
- 	   1	PMI diag: Depression	 .176		<.01	 	.031
- 	   2	Social support		-.361		<.001		.499
- 		Negative cognitions		 .214		 [.08]
- 		Soc sup X Neg cog		 .268		<.05
-     	_   __3__	__Group__	__	__-.212__	__	__<.001__	__	__.027_
- 						Total R2 =	.558
- Remaining partial correlation of Group with Depression = -.24 (p<.001)

**Notes:**
If group is entered before SS & Cog, the initial beta for group is -.533 (which drops to the -.212 shown above when SS, cognitions, and interaction are added in)

## DV: PTSD score
Correlations:
			PTSD		Group	Soc Sup
	Group (MI+:1, MI-:2)	-.49**	
	Social Support	-.50**	  	.34**
	Negative Cognitions	 .77**	 	-.42**	   -.54**

Regression
	Block	Predictors		   β		   p	  	 ΔR2
	   1	PMI diagnosis:PTSD		 .094		<.05	 	.146
	   2	Social support		-.279		<.001		.490
		Negative cognitions		 .343		<.01
		Soc sup X Neg cog		 .271		<.01
    	   3	Group		-.121		<.01		.008
						Total R2 =	.644
Remaining partial correlation of Group with PTSD = -.15 (p<.01)

- _Correlations:_
- 			PTSD		Group	Soc Sup
- 	Group (MI+:1, MI-:2)	-.49**
- 	Social Support	-.50**	  	.34**
- 	Negative Cognitions	 .77**	 	-.42**	   -.54**
- _Regression_
- 	_Block__	__Predictors__	__	__   __β__	__	__   p__	__  __	__ __Δ__R__2_
- 	   1	PMI diagnosis:PTSD		 .094		<.05	 	.146
- 	   2	Social support		-.279		<.001		.490
- 		Negative cognitions		 .343		<.01
- 		Soc sup X Neg cog		 .271		<.01
-     	_   __3__	__Group__	__	__-.121__	__	__<.01__	__	__.008_
- 						Total R2 =	.644
- Remaining partial correlation of Group with PTSD = -.15 (p<.01)

**Notes:**
If group is entered before SS & Cog, the initial beta for group is -.412 (which drops to the -.121 shown above when SS, cognitions, and interaction are added in)

## DV: Panic Disorder score
Correlations:
  		                                  Panic		Group	Soc Sup
	Group (MI+:1, MI-:2)	-.43**	
	Social Support	-.42**	  	.34**
	Negative Cognitions	 .58**	 	-.42**	   -.54**

Regression
	Block	Predictors		   β		   p	  	 ΔR2
	   1	PMI diagnosis: PD		 .008		  ns	 	.006
	   2	Social support		-.176		 [.08] 		.345
		Negative cognitions		 .336		<.05
		Soc sup X Neg cog		 .079		  ns
    	   3	Group		-.205		<.001		.033
						Total R2 =	.384
Remaining partial correlation of Group with Panic = -.23 (p<.001)

- _Correlations:_
-   		                                  Panic		Group	Soc Sup
- 	Group (MI+:1, MI-:2)	-.43**
- 	Social Support	-.42**	  	.34**
- 	Negative Cognitions	 .58**	 	-.42**	   -.54**
- _Regression_
- 	_Block__	__Predictors__	__	__   __β__	__	__   p__	__  __	__ __Δ__R__2_
- 	   1	PMI diagnosis: PD		 .008		  ns	 	.006
- 	   2	Social support		-.176		 [.08] 		.345
- 		Negative cognitions		 .336		<.05
- 		Soc sup X Neg cog		 .079		  ns
-     	_   __3__	__Group__	__	__-.205__	__	__<.001__	__	__.033_
- 						Total R2 =	.384
- Remaining partial correlation of Group with Panic = -.23 (p<.001)

**Notes:**
If group is entered before SS & Cog, the initial beta for group is -.424 (which drops to the -.205 shown above when SS, cognitions, and interaction are added in)

## DV: GAD score
Correlations:
  		                             	GAD		Group	Soc Sup
	Group (MI+:1, MI-:2)	-.50**	
	Social Support	-.50**	  	.34**
	Negative Cognitions	 .73**	 	-.42**	   -.54**

Regression
	Block	Predictors		   β		   p	  	 ΔR2
	   1	PMI diagnosis: GAD		 .033		  ns	 	.011
	   2	Social support		-.365		<.001 		.561
		Negative cognitions		 .190		  ns
		Soc sup X Neg cog		 .356		<.001
    	   3	Group		-.201		<.001		.032
						Total R2 =	.605
Remaining partial correlation of Group with GAD = -.27 (p<.001)

- _Correlations:_
-   		                             	GAD		Group	Soc Sup
- 	Group (MI+:1, MI-:2)	-.50**
- 	Social Support	-.50**	  	.34**
- 	Negative Cognitions	 .73**	 	-.42**	   -.54**
- _Regression_
- 	_Block__	__Predictors__	__	__   __β__	__	__   p__	__  __	__ __Δ__R__2_
- 	   1	PMI diagnosis: GAD		 .033		  ns	 	.011
- 	   2	Social support		-.365		<.001 		.561
- 		Negative cognitions		 .190		  ns
- 		Soc sup X Neg cog		 .356		<.001
-     	_   __3__	__Group__	__	__-.201__	__	__<.001__	__	__.032_
- 						Total R2 =	.605
- Remaining partial correlation of Group with GAD = -.27 (p<.001)

**Notes:**
If group is entered before SS & Cog, the initial beta for group is -.493 (which drops to the -.201 shown above when SS, cognitions, and interaction are added in)

## Within-Group Exploratory Analyses

*To examine the relative impact of various risk factors and determine whether other predictors of post-disaster health outcomes are similar for individuals with and without pre-Katrina mental disorders.*
- For each mental health outcome, several variables were assessed as potential predictors in separate analyses for the MI+ group and the MI- group
- Which variables were useful predictors did differ between the groups.
- Due to multicollinearity of some predictors, and especially of predictors and associated interaction terms, the clearest illustration of the relative value of useful predictors emerges when the models are reduced only to those variables which contribute meaningful variance.

## Within-Group Exploratory Analyses

- _Potential Predictors:_
- Education
- Income (post-Katrina, showed stronger relations with outcomes)
- Race: AA vs. White/Other (Whites and Other/Mixed did not differ on outcomes)
- In affected area on day of Katrina
- Katrina Traumatic Events
- Katrina damage items endorsed
- Emotions felt during Katrina
- Hope for future
- Changes in worldview (spirituality, closeness to others, trust in others, sense of meaning & purpose in life)
- Social Support
- Negative Cognitions
- Interactions: Katrina Trauma x Cognitions, Social Support x Cognitions, Katrina Trauma x Social Support

## DV: PTSD Scale Score

	MI+					
	Predictor	   		   β	 	ΔR2 	   p 	
	 Race: African-Amer.		.118	.036	<.05	
	 Katrina trauma		.194	.250	<.001	
	 Negative cognitions		.638	.310	<.001	
                             	Total R2 =	.596		

MI–					
Predictor	   	    β	 ΔR2 	   p 	
 Feelings during Katrina	 .142	.183	<.001
 Social support	-.176	.080	<.001
 Negative cognitions	 .515	.296	<.001
 Social sup X K. trauma	 .302	.071	<.001
 	Total R2 =	.629	

**	****MI+**
**	**_**Predictor**__**	**__**   **__**	**__**	**__**   **__**β**__**	**__** **__**	**__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
- 	 Race: African-Amer.		.118	.036	<.05
- 	 Katrina trauma		.194	.250	<.001
- 	___ __Negative cognitions__	__	__.638__	__.310__	__<.001_
-                              	Total R2 =	.596
**MI–**
_**Predictor**__**	**__**   **__**	**__**    **__**β**__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
-  Feelings during Katrina	 .142	.183	<.001
-  Social support	-.176	.080	<.001
-  Negative cognitions	 .515	.296	<.001
- ___ __Social sup X K. trauma__	__ .302__	__.071__	__<.001_
-  	Total R2 =	.629

- High Trauma

- Moderate Trauma

- Low Trauma

## DV: Depression Scale Score 
MI+					
Predictor	   β	 ΔR2 	   p 	
 In affected area on K-day	 .164	.030	<.01	
 Social support	-.167	.210	<.05	
 Negative cognitions	 .519	.185	<.001	
                             	Total R2 =	.425		
MI–					
Predictor	   β	 ΔR2 	   p 	
 Education	-.132	.063	<.05
 Income	-.124	.073	<.05
 Worldview change	-.134	.061	<.05
 Negative cognitions	 .836	.283	<.001
 Social sup X Cognitions	-.382	.025	<.001
 Social sup X K. trauma	 .164	.019	<.05
 	Total R2 =	.530	

**MI+**
_**Predictor**__**	**__**   **__**β**__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
-  In affected area on K-day	 .164	.030	<.01
-  Social support	-.167	.210	<.05
- ___ __Negative cognitions__	__ .519__	__.185__	__<.001_
-                              	Total R2 =	.425
**MI–**
_**Predictor**__**	**__**   **__**β**__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
-  Education	-.132	.063	<.05
-  Income	-.124	.073	<.05
-  Worldview change	-.134	.061	<.05
-  Negative cognitions	 .836	.283	<.001
-  Social sup X Cognitions	-.382	.025	<.001
- ___ __Social sup X K. trauma__	__ .164__	__.019__	__<.05_
-  	Total R2 =	.530

**Notes:**
I cannot fit 2 interaction graphs on this slide, the significant interactions for the MI- group are on the next slide.

## DV: Depression Scale Score 
MI– Group

**MI– Group**

## DV: Panic Disorder Scale Score

MI+					
Predictor	   	   β	 ΔR2 	   p 	
 Income		 .185	.031	<.01	
 In area on K-day 	 .249	.048	<.001	
 Katrina trauma	 .173	.131	<.05	
 Social support	-.417	.066	<.001	
 Social sup X Cognitions	 .369	.112	<.001	
                                       Total R2 =	.387

	MI–					
	Predictor	  	 	    β	 	 ΔR2 	   p 	
	 Katrina Trauma			 .184		.108	<.05
	 Negative cognitions			 .339		.094	<.001
					Total R2 =	.202	

**MI+**
_**Predictor**__**	**__**   **__**	**__**   **__**β**__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
-  Income		 .185	.031	<.01
-  In area on K-day 	 .249	.048	<.001
-  Katrina trauma	 .173	.131	<.05
-  Social support	-.417	.066	<.001
- ___ __Social sup X Cognitions__	__ .369__	__.112__	__<.001_
-                                        Total R2 =	.387
**	****MI–**
_**	**__**Predictor**__**	**__**  **__**	**__** **__**	**__**    **__**β**__**	**__** **__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
- 	 Katrina Trauma			 .184		.108	<.05
- _	____ __Negative cognitions__	__	__	__ .339__	__	__.094__	__<.001_
- 					Total R2 =	.202

- High Neg. Cog.

- Moderate Neg. Cog.

- Low Neg. Cog.

## DV: GAD Scale Score

MI+					
Predictor	  	    β	 ΔR2 	   p 	
 In affected area on K-day	 .151	.025	<.01	
 Katrina trauma	 .161	.198	<.01	
 Social support	-.485	.086	<.001	
 Soc sup X Neg cog.	 .495	.220	<.001	
                                       Total R2 =	.529		

	MI–					
	Predictor			   β			 ΔR2 	   p 	
	 Education			-.124		.072	<.001
	 Katrina trauma			 .192		.204	<.001
	 Feelings during Katrina	 .139		.053	<.001
	 Social support			-.126		.070	<.001
	 Negative cognitions 		 .507		.176	<.001
 					   Total R2 =	.574

**MI+**
_**Predictor**__**	**__**  **__**	**__**    **__**β**__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
-  In affected area on K-day	 .151	.025	<.01
-  Katrina trauma	 .161	.198	<.01
-  Social support	-.485	.086	<.001
- ___ __Soc sup X Neg cog.__	__ .495__	__.220__	__<.001_
-                                        Total R2 =	.529
**	**
**	****MI–**
_**	**__**Predictor**__**	**__**	**__**	**__**   **__**β**__**	**__**	**__**	**__** **__**Δ**__**R**__**2**__** **__**	**__**   p**_** ****	**
- 	 Education			-.124		.072	<.001
- 	 Katrina trauma			 .192		.204	<.001
- 	 Feelings during Katrina	 .139		.053	<.001
- 	 Social support			-.126		.070	<.001
- _	____ __Negative cognitions __	__	__ .507__	__	__.176__	__<.001_
-  					   Total R2 =	.574

- High Neg. Cog.

- Moderate Neg. Cog.

- Low Neg. Cog.

## Conclusions

- As predicted, pre-existing mental illness does appear to predispose veterans to developing new mental disorders after facing a natural disaster.
- Those with PMI did report less social support and did exhibit more negative cognitive appraisals of the hurricane and their feelings and actions in response to it.
- Mediation analyses suggest that the group differences in mental health outcomes are partially mediated by the differences in social support and negative cognitions.  However, PMI still contributes unique variance to the explanation of mental health outcomes.
- Exploratory analyses of within-group determinants of negative mental health outcomes showed some differences in useful predictors between the groups. However, negative cognitions play some role in every prediction for both groups.