Nathan Hansen PhD

Associate Professor of Psychiatry; Director, Mental Health and HIV Prevention Research, The Consultation Center (TCC); Director, Development Core, Center for Interdisciplinary Research on AIDS (CIRA); Co-Director, HIV Prevention Training Program, CIRA

Research Interests

HIV Mental Health; HIV Prevention; Psychotherapy Outcome; Substance Abuse Prevention; Childhood Abuse; Interpersonal Violence

Current Projects

• PATH: Promoting Action Towards Health (Efficacy trial of a brief health enhancement intervention for newly diagnosed men): This randomized clinical trial will test the efficacy of the Positive Choices intervention, a brief health-enhancement and risk reduction intervention targeting newly HIV diagnosed men who have sex with men (MSM).
• Positive Living (Intervention to reduce acute stress and HIV risk in newly diagnosed men): This study evaluates a mental health and risk reduction intervention for newly HIV diagnosed men who have sex with men (MSM). The intervention combines cognitive-behavioral treatment for Acute Stress Disorder and HIV transmission risk reduction counseling,
• Reducing Violence and HIV Risk Among War-Exposed Liberian Youth: This project will develop, culturally adapt, and pilot test a group-based intervention for war-exposed youth in Liberia that integrates HIV prevention and mental health counseling.
• Facilitators and Barriers to Addressing Intimate Partner Violence in CT HIV/AIDS Service Agencies: The goal of this project is to assess the capacity of AIDS Service Organizations and AIDS Housing Providers to screen for and address interpersonal violence (IPV), and identify facilitators and barriers to screening for and addressing IPV from both staff and client perspectives.
• Identifying Adolescents at Risk for Transition into Injection Drug Use in Russian Cities: Preliminary research: In this pilot project, we will conduct interviews with community stakeholders, including adolescents and their parents, in order to develop a conceptual model of key risk and protective factors related to injection drug use and HIV risk among Russian adolescents and explore the legal, ethical, cultural, and methodological issues relevant to conducting longitudinal research on this topic.
• STAY Healthy (Intervention for HIV+ Adults with Childhood Sexual Abuse): This goal of this project is to develop and pilot test a 16-session cognitive-behavioral psychotherapy intervention for HIV-positive adult survivors of childhood sexual abuse with the dual aim of decreasing traumatic stress and decreasing HIV transmission-risk behavior.
• Positive Choices (Brief Care-based HIV Prevention for Newly Diagnosed Men): This is a study to establish the efficacy of a Brief Risk Reduction intervention among newly diagnosed HIV-positive men who have sex with men, in partnership with Callen-Lorde Community Health Center in New York City.

Research Summary

Dr. Hansen's research has focused on understanding the link between traumatic stress and negative health consequances, with a specific focus on substance abuse and HIV infection. Additionally, Dr. Hansen has conducted research developing group and individual psychotherapy approaches to reduce the negative health consequences of traumatic stress and enhance the functioning of people living with HIV infection. Some of these projects include developing psychotherapy interventions for people living with HIV who have lost loved ones to AIDS, people living with HIV who experienced childhood sexual abuse, older adults who are living with HIV, newly HIV diagnosed men, and abused women in South Africa.

Extensive Research Description

Dr. Hansen’s research interests include: (1) psychotherapy outcome research, (2) behavioral intervention development and evaluation, (3) understanding and treating the negative consequences of traumatic stress, and (4) preventing and treating HIV and substance use disorders. Dr. Hansen’s work in the area of psychotherapy outcome research has focused on developing and expanding patient-focused research methodology to improve mental health service delivery through predicting and preventing treatment failures. This includes expanding methodology for establishing the clinical significance of patient change, evaluating the dose-response relationship in individual and group psychotherapy, developing measures of psychotherapy outcome, and the identification of and intervention with potential treatment failures to improve patient outcomes.

Dr. Hansen has considerable experience in intervention development having served as an investigator on several NIH-funded randomized controlled trials of interventions to enhance the mental health and coping of people living with HIV, as well as numerous additional studies on the impact of trauma, particularly interpersonal violence, on the mental health and risk behavior of people living with HIV. Examples include:

Intervention for Coping with AIDS-Related Bereavement (R01 MH54958): was a randomized, controlled trial (RCT) of a group intervention for coping with bereavement from the AIDS-related death of a loved one in 268 HIV-positive individuals (174 men and 94 women). Assessments of distress and coping were conducted at baseline, post-, and 4-, 8- and 12-month follow-up points, with follow-up retention rates exceeding 80%. We found that participants in the group intervention condition had significant improvements in grief, distress and health-related quality of life compared to participants in the comparison condition, and improvements persisted across a one-year follow-up.

Intervention for Coping with HIV and Trauma (R01 MH62965): was an RCT of a coping and secondary HIV prevention group intervention for people living with HIV who had experienced sexual abuse as a child or adolescent (124 men, 131 women). This project compared a 15-week coping intervention to a 15-week support group intervention and a waitlist control group, with assessments conducted at baseline, post-, and 4-, 8- and 12-month follow-up points. After the waitlist period, participants in the waitlist condition were assigned to one of the two intervention conditions. The 1-year follow-up retention rate was 75%. We found that participants in the coping group intervention had significant reductions in trauma symptoms at post intervention and HIV transmission risk behavior after a one-year follow-up period in comparison to participants in the support group condition and the waitlist control condition.

A Coping Intervention for HIV-Infected Older Adults (R01 MH067566): was an RCT of a group intervention for coping with aging and HIV infection among HIV-infected people over 50 years of age. This was the first behavioral intervention study of its kind conducted with this population. Between 2004 and 2007 we recruited 307 participants through AIDS service organizations (ASOs), community based organizations and hospitals in New York City, Columbus, OH, and Cincinnati, OH. Participants were randomized into one of three conditions, a 12-session coping improvement group intervention, a 12-session “generativity” group intervention, or an individual therapy upon request control condition. Post-treatment analyses of outcome demonstrated significant reductions in depression for participants in the coping intervention, and that, consistent with Social Cognitive Theory, changes were mediated by self-efficacy beliefs. We also observed high rates of sexual activity in this sample, particularly among heterosexually-identified men, with 33% of sexually active participants engaging in high HIV-transmission risk behavior.

Risk-Reduction and Empowerment Intervention for South African Women who have Experienced Intimate Partner Violence and Sexual Assault: was a community-based study with South African partners People Opposing Woman Abuse (POWA) and the University of Pretoria conducted in women’s shelters and clinics in Johannesburg and the surrounding townships. Based on qualitative research with women seeking services from POWA we developed a culturally-tailored group intervention that integrated issues of gender and power imbalance with HIV prevention strategies and techniques to address traumatic stress related to gender-based violence. Because the acceptability of a group intervention for women experiencing gender-based violence in and around Johannesburg was unknown, we recruited 97 women seeking services from POWA with 45 assigned to a 6-weekly session group intervention and 52 to a 1 day workshop with a scaled back version of the same curriculum. Women completed assessments that were translated and culturally adapted into Zulu and Sotho at baseline and post intervention. African group leaders from POWA and the University of Pretoria were trained in delivering the intervention. Of participants assigned to the 6-session group, 98% attended 5 or more of the 6-session groups; for the 1-day workshop, 94% attended both the morning and afternoon sessions. A high follow-up rate was achieved post intervention (83%). Both conditions achieved significant improvements at post intervention on outcome measures, including sexual risk behavior and traumatic stress, while the 6-session group had a significant advantage in increasing HIV knowledge and risk reduction intentions.

Prevention with Newly HIV+ Men: A Pilot Intervention (P30 MH62294-05S2): was a pilot test of the 3 session brief risk reduction intervention Positive Choices with newly HIV diagnosed men who have sex with men entering care in New York City. Over a 10-month period (11/06-08/07), we enrolled 65 participants. Inclusion criteria included: (1) diagnosis of HIV+ serostatus within the past 3 months; (2) male-to-male sexual behavior or self-identification as a gay or bisexual male; (3) unprotected anal intercourse in the 3 months prior to diagnosis; (4) age 18 or older; and (5) provision of written informed consent. Men were randomly assigned to a comprehensive standard of care (CSC) comparison condition (n=30) or the experimental intervention (consisting of CSC and Positive Choices) condition (n=35). Participants completed a baseline assessment, and three 50-minute individual sessions were delivered to participants in the experimental condition. Follow-up assessments were administered three and six months after the baseline. CSC participants increased risk from pre-intervention levels across number of sex partners and number of unprotected anal sexual acts, while Positive Choices participants reduced sexual risk behaviors. Additionally, Positive Choices participants reported greater increases in services utilized (d = .80), with a large percentage of the increased service utilization within the mental health services area. Effect sizes for these variables provide support for the potential efficacy of the Positive Choices intervention for risk reduction. Additionnally, these outcomes were maintained at the 6-month follow-up, with Positive Choices participants continuing to report greater behavioral risk reduction than CSC participants (effect sizes ranging from .20 - .50). It should be noted that our observed effect size for unprotected anal intercourse at 6-month follow-up (d = .40) is almost triple that reported in a meta-analysis (.16) of other secondary intervention studies.

Brief Care-based HIV Prevention for Newly Diagnosed Men (R01 MH078731): Is an ongoing randomized controlled trial of the Positive Choices intervention described above. This study will enroll 120 newly HIV diagnosed men who have sex with men and randomly assign them to a comprehensive standard of care (CSC) comparison condition or the experimental intervention (consisting of CSC and Positive Choices) condition.

Intervention for HIV+ Adults with Childhood Sexual Abuse (K23 MH076671): In an ongoing project developing the STAY Healthy (Sexual Trauma And Your Health) intervention, a 16 session individually-focused, cognitive-behavioral psychotherapy intervention for people living with HIV who were sexually abused as children or adolescents. While this intervention is trauma-focused and aims to reduce trauma symptoms and sexual and substance use-related HIV-risk behavior, it also has a strong health enhancement focus aiming to increase treatment adherence and health-protective behavior. This study will recruit 80 people living with HIV who have experienced childhood sexual abuse and randomly assign them to an immediate treatment condition or a 4-month waitlist condition.

Selected Publications