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Sexx Matters

Gender Differences in Posttraumatic Stress Disorder

Jennifer Wider, MD; Eileen Resnick, PhD

According to the National Institute of Mental Health, posttraumatic stress disorder (PTSD) is a debilitating condition affecting approximately 5.2 million adults in the United States.¹ People with PTSD experience neurobiologic and physiologic symptoms—including anxiety-type reactions such as increased heart rate, sweating, and breathing difficulties—as a result of exposure to various types of trauma (eg, war experiences, violent attacks, serious accidents, terrorism).^2-5

The three groups of symptoms for diagnosing PTSD as indicated in the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) include reexperiencing the trauma, avoidance and numbing, and hyperarousal.³ According to the US Department of Veterans Affairs (VA), a diagnosis of PTSD is established if symptoms persist for longer than 1 month, cause personal distress, and interfere with an individual's ability to function. Recovery from PTSD usually requires 3 to 5 years; however, some people may suffer for a decade or a lifetime.^6,7 While PTSD imposes an enormous physical and mental burden on patients, it remains one of the most difficult mental illnesses to diagnose in primary care.⁸ Therefore, physicians must be aware of the numerous manifestations of PTSD, including both psychiatric and nonpsychiatric symptoms, to effectively diagnose and treat patients suffering from this devastating disorder.

Posttraumatic stress disorder can be treated effectively with a variety of therapies and/or medications. The key is recognizing the signs and symptoms. It usually presents within 3 months of the traumatic event, but can appear later as well. According to the APA, physicians should consider PTSD in patients with the following symptoms: unexpected flashbacks; strong feelings of grief, anger, depression, and/or guilt; nightmares; startle reactions; insomnia or other sleep disorders; anxiety or panic attacks; and suicidal ideation. Physicians should also be aware that people with PTSD may present with nonpsychological symptoms, including memory problems, learning difficulties, social impairment, and poor concentration. Recent studies have shown that victims of trauma may experience physical changes in the hippocampus, a part of the brain responsible for memory and learning.⁹

The VA's National Center for PTSD notes that PTSD shares many psychological symptoms with acute stress disorder (ASD), which was introduced into the DSM-IV in 1994. One difference between the two disorders is that ASD is characterized by a greater number of dissociative symptoms—ie, the unconscious separation of a group of mental processes from the rest. A diagnosis of ASD is established if patients present with symptoms for at least 2 days but no more than 4 weeks, whereas PTSD is characterized by symptoms that persist for longer periods. Studies have shown that a diagnosis of ASD is a strong predictor for the future development of PTSD, especially in women, so physicians should be aware of specific strategies to prevent progression from ASD to PSTD.^10-13 Other studies have demonstrated that cognitive-behavioral interventions are the most successful mechanisms to prevent development of PTSD after ASD diagnosis.^14-16

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INCIDENCE

Epidemiologic surveys of the general population indicate that the lifetime prevalence of PTSD is 7.8%, with women approximately twice as likely to develop PTSD as men.⁶ Although men tend to experience more traumatic events in their lifetime, women are more likely to develop PTSD as a result of trauma.³ Some researchers suggest that women may be more susceptible to PTSD because they are at a greater risk for the more severe types of traumatic events, such as assault violence and rape.¹⁷ However, when men and women are exposed to the same types of trauma, women are still more likely to develop PTSD.^3,6,18 Some studies suggest that women experience more acute PTSD compared with men, while others report that chronic PTSD shows no gender differences.^4,5,19 Further research has demonstrated that women experience symptoms of PTSD for a longer duration than men.²⁰ The types and history of trauma, preexisting mental health problems, societal roles, and neurobiology may contribute to the gender differences observed in PTSD incidence, symptoms, and treatment. However, the extent to which these issues play a role in the etiology of PTSD in women remains controversial and an active area of scientific study.

A history of maltreatment in childhood (ie, physical, psychological, sexual abuse) has been shown to be a stronger predictor for the future development of PTSD in women compared with men.²¹ Childhood maltreatment has been associated with a greater likelihood of PTSD, substance abuse, and depression in women compared with women who were not abused as children.²² Breslau et al²³ reported that women with PTSD were twice as likely as men to have depression and anxiety disorders prior to the diagnosis of PTSD. Given that in the general population, women are 2-fold to 3-fold as likely to suffer from depression as men,²⁴ this preexisting mental illness may contribute to the higher PTSD incidence in women. However, there is no consensus in the literature regarding previous depression or anxiety disorder as a true risk factor for PTSD development in either women or men.^18,23,25

Pulcino et al²⁶ stated that women may have experienced greater rates of PTSD after the September 11, 2001 terrorist attacks on the World Trade Center in New York City because they are more likely to have the societal role of primary family caretakers, which carries a large perceived burden. Women in this population with less social support were more likely to develop PTSD, whereas this correlation was not observed in men. In addition, several studies of PTSD in the general population have indicated that social support was more important for the mental health of women than men.^2,27-31 However, the inverse relationship between degree of social support and PTSD risk is not confined to women; it may be related to specific cultural values, as indicated among postwar populations in various countries.^27,32 Therefore, targeting both women and men with low social support may help to prevent and treat PTSD after traumatic episodes.^26,27

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BIOLOGIC RESPONSE

Trauma may elicit different physiologic and neurobiologic responses in men and women, such as those associated with regulation of the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis coordinates the stress response, and dysregulation of this tightly balanced circuit can occur in people with PTSD.²¹ The adrenal hormone cortisol functions in times of stress to regulate cardiovascular function, blood pressure, and the metabolism of proteins, fats, and carbohydrates. Studies have demonstrated inconsistent results in relation to cortisol, as both increases and decreases in the hormone have been reported in patients with PTSD.^21,33,34 Comparison of the numerous studies measuring cortisol levels in PTSD is difficult, because the types and timing of traumatic events (eg, combat/noncombat, recent/past, chronic/acute), gender, and comorbidity appear to influence the results.²¹ Other adrenal hormones involved in stress include epinephrine and norepinephrine, which are catecholamines that modulate cardiovascular function, breathing, and fat metabolism. Studies comparing catecholamine levels in men and women with PTSD are relatively limited, but one study of PTSD development following a motor vehicle accident demonstrated that high levels of catecholamines correlated with PTSD in men but not in women.³⁵ The steroid hormones estrogen and progesterone, which are modulated by the hypothalamic-pituitary-ovarian axis, may also influence the stress response in women. Both hormones can regulate neurotransmission of norepinephrine and serotonin—the two neurotransmitters implicated in depression.³⁶

The imbalance in PTSD incidence may be related to the way the sexes respond psychologically to the effects of trauma.³ Results of one study evaluating sex differences in PTSD development after motor vehicle accidents reported that women were more than four times as likely to suffer from PTSD. Peritraumatic dissociation at the time of the accident was equally likely in men and women, but it was a greater risk factor for development of PTSD in women compared with men.¹⁸ In addition, a study of more than 2,000 people in the general population showed that following assaultive violence, women may be at higher risk for PTSD because they are more likely to experience symptoms of avoidance and numbing compared with men.3³

It has been noted that PTSD is associated with an increased incidence of comorbid psychiatric disorders, and according to the National Comorbidity Survey (NCS),⁶ there are sex differences in the types of comorbidities experienced by patients with PTSD. The survey showed that women were more likely to have comorbid panic disorder, and men were more likely to be substance abusers and have conduct disorder and mania. The VA stated that in a large-scale study, comorbid psychiatric disorders were evident in 88% of men and 79% of women with PTSD.³⁷ Men most likely exhibited concomitant alcohol abuse or dependency (~52%), major depressive episodes (~48%), conduct disorders (~43%), and drug abuse and dependency (~35%). Comorbid major depressive disorders (~49%), simple phobias (29%), social phobias (~28%), and alcohol abuse/ dependency (~28%) were more common in women.

Women and men with PTSD commonly report nonpsychiatric comorbidities and poor physical health.^38-46 Given that patients with PTSD are likely to experience and seek medical care for severe nonpsychiatric illnesses, most clinicians meet PTSD patients in the primary care setting as opposed to mental health clinics.^45,47,48 However, PTSD is one of the most difficult illnesses to diagnose in the primary care setting.⁸ Therefore, primary care physicians must be cognizant of any history of trauma or psychiatric illnesses in their patients to assess for the possibility of PTSD. Reports have indicated that individuals exposed to trauma in childhood or adulthood were more likely to experience fibromyalgia, irritable bowel syndrome, and coronary artery disease; participate in risk-seeking behaviors; and report physical symptoms.^45,49-57 Among almost 6,000 men and women analyzed in the NCS,⁵⁸ PTSD was associated with a greater than 2-fold risk of a current medical condition than those without PTSD. Although gender was not related to the frequency of nonpsychiatric health conditions in these PTSD patients, depression and poverty were linked to an increased likelihood of comorbid medical conditions in women but not in men. Interestingly, certain serious, chronic health conditions (eg, hypertension, diabetes) were more common in women than in men, indicating that women with PTSD may need more aggressive preventive health care.

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TREATMENT

According to the National Center for PTSD, both nonpharmacologic and pharmacologic therapies are available to treat patients with PTSD.⁵⁹ Treatments should be customized to the individual patient, and initiated only when the patient is no longer in the traumatic situation. Many patients benefit from a combination of psychological therapy and medication. Some may recover spontaneously from PTSD within 1 year, whereas others may develop chronic PTSD and require long-term treatment.^6,60

Psychological Therapy

Several psychological treatments for PTSD are similar to those used for other mental health disorders, but some are specific to trauma victims. Cognitive behavioral therapy (CBT) is an important component of treatment for PTSD, and involves working with the patient's thoughts and behaviors to create better coping strategies.

Exposure therapy is a specific type of CBT that involves reexperiencing the trauma in a safe environment to promote better coping mechanisms. Patients learn to control their anxiety responses so that they can remember the event without panicking. This type of therapy can be used to treat a variety of patients, including those suffering from trauma, agoraphobia, and obsessive-compulsive disorder.

Eye-movement desensitization and reprocessing is a relatively new approach that attempts to prompt "alternation of attention" through rapid eye movement, resulting in processing of traumatic memories. The patient is able to address past and present experiences in short, sequential doses while focusing on an external stimulus. This treatment modality is becoming more popular.

Psychodynamic psychotherapy involves understanding emotions related to the trauma and childhood experiences. Patients focus on how past trauma can affect present experiences. Group therapy may also be beneficial for PTSD patients who find comfort in being surrounded by others with similar experiences. Currently, the VA is recruiting women with military experience and PTSD to participate in a clinical trial to evaluate two types of psychotherapy.

Pharmacotherapy

Pharmacologic therapy is often used in conjunction with nonpharmacologic measures to reduce the anxiety, depression, and insomnia associated with PTSD. Selective serotonin reuptake inhibitors (SSRIs) have been the most widely studied drugs for use in patients with PTSD.⁷ The SSRIs sertraline and paroxetine have been approved by the US Food and Drug Administration for the treatment of PTSD and are considered first-line agents. Gender differences in response to treatment with sertraline were demonstrated in a double-blind, placebo-controlled trial of 187 PTSD patients.⁶¹ Subjects were randomized to receive either placebo or sertraline at 25 mg/d for 1 week, followed by flexible doses of 50 to 200 mg/d. Women with PTSD experienced significant improvement in symptoms compared with men.

Although not considered first-line therapy for PTSD, tricyclic antidepressants (TCAs) may also be administered to combat the PTSD-associated symptom of depression. In a study of 235 men and 400 women with depression, the efficacy of sertraline versus the TCA imipramine was significantly different between the sexes.⁶² Sertraline was more efficacious in women, and imipramine was more efficacious in men. In addition, women taking imipramine were more likely to leave the study than those using sertraline, while men taking sertraline were more likely to leave than those using imipramine.

Other pharmacotherapies for PTSD include non-SSRIs (eg, mirtazapine, nefazodone, trazodone, venlafaxine), as well as mono-amine oxidase inhibitors.⁷ These agents have not been evaluated as extensively as SSRIs for PTSD, may be less efficacious, and may have more adverse side effects. In addition, anticonvulsants (eg, carbamazepine, gabapentin, lamotrigine, valproic acid) may be effective in PTSD patients exhibiting bipolar disorder or anger.

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CONCLUSION

Posttraumatic stress disorder remains a serious international public health concern because of its high incidence and severe symptoms in both women and men. However, PTSD often goes unrecognized in the clinical setting. Physicians must be cognizant not only of symptoms associated with PTSD, but that it is a treatable condition requiring collaboration among multiple clinical specialties—especially for rape victims. Proper management of PTSD is essential for the patient's well-being and ability to lead a healthy, productive life.

As researchers continue to study the epidemiology, neurobiology, and therapies associated with PTSD, the influence of gender differences in each of these areas is becoming more evident. Continued evaluation of sex differences in PTSD at the basic scientific, clinical, and behavioral levels will lead to the development of appropriate preventive and therapeutic programs that will utilize these inherent differences. The anticipated results of these efforts will enhance the quality of life for both women and men who are adversely affected by traumatic events in their lives, helping to prevent the subsequent development of PTSD.

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Jennifer Wider, MD, is medical advisor, and Eileen Resnick, PhD, is scientific program manager; both are at the Society for Women's Health Research, Washington, DC.

References

1. Facts about Post-Traumatic Stress Disorder. National Institute of Mental Health Web site. Available at: http:// www.nimh.nih.gov/publicat/ptsdfacts. cfm. Accessed February 11, 2005.
2. Bond EF. Women's physical and mental health sequellae of wartime service. Nurs Clin North Am. 2004;39(1):53-68.
3. Breslau N, Chilcoat HD, Kessler RC, Peterson EL, Lucia VC. Vulnerability to assaultive violence: further specification of the sex difference in post-traumatic stress disorder. Psychol Med. 1999;29(4):813-821.
4. Ursano RJ, Fullerton CS, Epstein RS, et al. Acute and chronic posttraumatic stress disorder in motor vehicle accident victims. Am J Psychiatry. 1999:156(4):589-595.
5. Grieger TA, Fullerton CS, Ursano RJ. Posttraumatic stress disorder, depression, and perceived safety 13 months after September 11. Psychiatr Serv. 2004;55(9):1061-1063.
6. Kessler RC, Sonnega A, Bromet E, Hughes M, Nelson CB. Posttraumatic stress disorder in the National Comorbidity Survey. Arch Gen Psychiatry. 1995;52(12):1048-1060.
7. Asnis GM, Kohn SR, Henderson M, Brown NL. SSRIs versus non-SSRIs in post-traumatic stress disorder: an update with recommendations. Drugs. 2004;64(4):383-404.
8. Schonfeld WH, Verboncoeur CJ, Fifer SK, Lipschutz RC, Lubeck DP, Buesching DP. The functioning and well-being of patients with unrecognized anxiety disorders and major depressive disorder. J Affect Disord. 1997;43(2):105-119.
9. Bremner JD, Narayan M. The effects of stress on memory and the hippocampus throughout the life cycle: implications for childhood development and aging. Dev Psychopathol. 1998;10(4):871-885.
10. Bryant RA, Harvey AG. Gender differences in the relationship between acute stress disorder and posttraumatic stress disorder following motor vehicle accidents. Aust N Z J Psychiatry. 2003;37(2):226-229.
11. Bryant RA, Harvey AG. Relationship between acute stress disorder and posttraumatic stress disorder following mild traumatic brain injury. Am J Psychiatry. 1998;155(5):625-629.
12. Brewin CR, Andrews B, Rose S, Kirk M. Acute stress disorder and posttraumatic stress disorder in victims of violent crime. Am J Psychiatry. 1999; 156(3):360-366.
13. Harvey AG, Bryant RA. The relationship between acute stress disorder and posttraumatic stress disorder: a prospective evaluation of motor vehicle accident survivors. J Consult Clin Psychol. 1998;66(3):507-512.
14. Bryant RA, Sackville T, Dang ST, Moulds M, Guthrie R. Treating acute stress disorder: an evaluation of cognitive behavior therapy and supportive counseling techniques. Am J Psychiatry. 1999;156(11):1780-1786.
15. Bryant RA, Harvey AG, Dang ST, Sackville T, Basten C. Treatment of acute stress disorder: a comparison of cognitive-behavioral therapy and supportive counseling. J Consult Clin Psychol. 1998;66(5):862-866.
16. Gidron Y, Gal R, Freedman S, et al. Translating research findings to PTSD prevention: results of a randomized-controlled pilot study. J Trauma Stress. 2001;14(4):773-780.
17. Solomon SD, Davidson JR. Trauma: prevalence, impairment, service use, and cost. J Clin Psychiatry. 1997; 58(Suppl 9):5-11.
18. Fullerton CS, Ursano RJ, Epstein RS, et al. Gender differences in posttraumatic stress disorder after motor vehicle accidents. Am J Psychiatry. 2001; 158(9):1486-1491.
19. Grieger TA, Fullerton CS, Ursano RJ. Posttraumatic stress disorder, alcohol use, and perceived safety after the terrorist attack on the Pentagon. Psychiatr Serv. 2003;54(10):1380-1382.
20. Breslau N. Gender differences in trauma and posttraumatic stress disorder. J Gend Specif Med. 2002;5(1):34-40.
21. Shea A, Walsh C, Macmillan H, Steiner M. Child maltreatment and HPA axis dysregulation: relationship to major depressive disorder and post traumatic stress disorder in females. Psychoneuroendocrinology. 2005; 30(2):162-178.
22. Arias I. The legacy of child maltreatment: long-term health consequences for women. J Womens Health (Larchmt). 2004; 13(5):468-473.
23. Breslau N, Davis GC, Andreski P, Peterson EL, Schultz LR. Sex differences in posttraumatic stress disorder. Arch Gen Psychiatry. 1997;54(11): 1044-1048.
24. Burt VK, Stein K. Epidemiology of depression throughout the female life cycle. J Clin Psychiatry. 2002;63(Suppl 7):9-15.
25. Bromet E, Sonnega A, Kessler RC. Risk factors for DSM-III-R posttraumatic stress disorder: findings from the National Comorbidity Survey. Am J Epidemiol. 1998;147(4):353-361.
26. Pulcino T, Galea S, Ahern J, Resnick H, Foley M, Vlahov D. Posttraumatic stress in women after the September 11 terrorist attacks in New York City. J Womens Health (Larchmt). 2003; 12(8):809-820.
27. Ahern J, Galea S, Fernandez WG, Koci B, Waldman R, Vlahov D. Gender, social support, and posttraumatic stress in postwar Kosovo. J Nerv Ment Dis. 2004;192(11):762-770.
28. Berkman LF, Glass T, Brissette I, Seeman TE. From social integration to health: Durkheim in the new millennium. Soc Sci Med. 2000;51(6):843-857.
29. Bultmann U, Kant IJ, Van den Brandt PA, Kasl SV. Psychosocial work characteristics as risk factors for the onset of fatigue and psychological distress: prospective results from the Maastricht Cohort Study. Psychol Med. 2002;32(2):333-345.
30. Kawachi I, Berkman LF. Social ties and mental health. J Urban Health. 2001;78(3):458-467.
31. Olstad R, Sexton H, Sogaard AJ. The Finnmark Study. A prospective population study of the social support buffer hypothesis, specific stressors and mental distress. Soc Psychiatry Psychiatr Epidemiol. 2001;36(12): 582-589.
32. Farhood L, Zurayk H, Chaya M, Saadeh F, Meshefedjian G, Sidani T. The impact of war on the physical and mental health of the family: the Lebanese experience. Soc Sci Med. 1993;36(12):1555-1567.
33. Rasmusson AM, Lipschitz DS, Lang S, et al. Increased pituitary and adrenal reactivity in premenopausal women with posttraumatic stress disorder. Biol Psychiatry. 2001;50(12):965-977.
34. Yehuda R. Biology of posttraumatic stress disorder. J Clin Psychiatry. 2000; 61(Suppl 7):14-21.
35. Hawk LW, Dougall AL, Ursano RJ, Baum A. Urinary catecholamines and cortisol in recent-onset posttraumatic stress disorder after motor vehicle accidents. Psychosom Med. 2000;62(3): 423-434.
36. Seedat S, Stein DJ. Trauma and post-traumatic stress disorder in women: a review. Int Clin Psychopharmacol. 2000;(15 Suppl 3):S25-S33.
37. What is posttraumatic stress disorder? National Center for PTSD web site. Available at: http://www.ncptsd.org/ facts/general/fs_what_is_ptsd.html. Accessed February 10, 2005.
38. Schnurr PP, Friedman MJ, Sengupta A, Jankowski MK, Holmes T. PTSD and utilization of medical treatment services among male Vietnam veterans. J Nerv Ment Dis. 2000;188(8):496-504.
39. Stein MB, McQuaid JR, Pedrelli P, Lenox R, McCahill ME. Posttraumatic stress disorder in the primary care medical setting. Gen Hosp Psychiatry. 2000;22(4):261-269.
40. Beckham JC, Moore SD, Feldman ME, Hertzberg MA, Kirby AC, Fairbank JA.. Health status, somatization, and severity of posttraumatic stress disorder in Vietnam combat veterans with posttraumatic stress disorder. Am J Psychiatry. 1998;155(11):1565-1569.
41. Zoellner LA, Goodwin ML, Foa EB. PTSD severity and health perceptions in female victims of sexual assault. J Trauma Stress. 2000;13(4):635-649.
42. Zatzick DF, Weiss DS, Marmar CR, et al. Post-traumatic stress disorder and functioning and quality of life outcomes in female Vietnam veterans. Mil Med. 1997;162(10):661-665.
43. Wagner AW, Wolfe J, Rotnitsky A, Proctor SP, Erickson DJ. An investigation of the impact of posttraumatic stress disorder on physical health. J Trauma Stress. 2000;13(1):41-55.
44. Wolfe J, Brown PJ, Bucsela ML. Symptom responses of female Vietnam veterans to Operation Desert Storm. Am J Psychiatry. 1992;149(5):676-679.
45. Dobie DJ, Kivlahan DR, Maynard C, Bush KR, Davis TM, Bradley KA. Posttraumatic stress disorder in female veterans: association with self-reported health problems and functional impairment. Arch Intern Med. 2004; 164(4):394-400.
46. Self-reported illness and health status among Gulf War veterans. A population-based study. The Iowa Persian Gulf Study Group. JAMA. 1997; 277(3):238-245.
47. Hoff RA, Rosenheck RA. The use of VA and non-VA mental health services by female veterans. Med Care. 1998; 36(11):1524-1533.
48. Samson AY, Bensen S, Beck A, Price D, Nimmer C. Posttraumatic stress disorder in primary care. J Fam Pract. 1999;48(3):222-227.
49. Felitti VJ, Anda F, Nordenberg D, et al. Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. The Adverse Childhood Experiences (ACE) Study. Am J Prev Med. 1998; 14(4):245-258.
50. Boscarino JA, Chang J. Electrocardiogram abnormalities among men with stress-related psychiatric disorders: implications for coronary heart disease and clinical research. Ann Behav Med. 1999;21(3)227-234.
51. Hankin CS, Skinner KM, Sullivan LM, Miller DR, Frayne S, Tripp TJ. Prevalence of depressive and alcohol abuse symptoms among women VA outpatients who report experiencing sexual assault while in the military. J Trauma Stress. 1999;12(4):601-612.
52. Koss MP, Woodruff WJ, Koss PG. Relation of criminal victimization to health perceptions among women medical patients. J Consult Clin Psychol. 1990;58(2):147-152.
53. McFall ME, Mackay PW, Donovan DM. Combat-related posttraumatic stress disorder and severity of substance abuse in Vietnam veterans. J Stud Alcohol. 1992;53(4):357-363.
54. Sibai AM, Armenian HK, Alam S. Wartime determinants of arteriographically confirmed coronary artery disease in Beirut. Am J Epidemiol. 1989;130(4):623-631.
55. Springs FE, Friedrich WN. Health risk behaviors and medical sequelae of childhood sexual abuse. Mayo Clin Proc. 1992;67(6):527-532.
56. van der Kolk BA, Pelcovitz D, Roth S, Mandel FS, McFarlane A, Herman JL. Dissociation, somatization, and affect dysregulation: the complexity of adaptation of trauma. Am J Psychiatry. 1996;153(7 Suppl):83-93.
57. Walker EA, Katon WJ, Roy-Byrne PP, Jemelka RP, Russo J. Histories of sexual victimization in patients with irritable bowel syndrome or inflammatory bowel disease. Am J Psychiatry. 1993;150(10):1502-1506.
58. Kimerling R. An investigation of sex differences in nonpsychiatric morbidity associated with posttraumatic stress disorder. J Am Med Womens Assoc. 2004;59(1):43-47.
59. Treatment of PTSD. National Center for PTSD web site. Available at: http://www.ncptsd.org/facts/treatment/fs_treatment.html. Accessed February 10, 2005.
60. Ballenger JC, Davidson JR, Lecrubier Y, et al. Consensus statement on posttraumatic stress disorder from the International Consensus Group on Depression and Anxiety. J Clin Psychiatry. 2000;(61 Suppl 5):60-66.
61. Brady KT, Randall CL. Gender differences in substance use disorders. Psychiatr Clin North Am. 1999;22(2): 241-252.
62. Kornstein SG, Schatzberg AF, Thase ME, et al. Gender differences in treatment response to sertraline versus imipramine in chronic depression. Am J Psychiatry. 2000;157(9):1445-1452.