and sexual risk taking into the broader context of sexuality, sexual behavior, and sexually transmitted diseases.

Understanding the biological basis of drug addiction is an important link to understanding drug abuse behaviors, and unlike the biology of sexuality has been the object of a great deal of research. Recent studies on the cellular and molecular basis of dependence and tolerance suggest that the processes are separate and distinct, and are mediated by different brain systems. The actual anatomical circuits in the brain that participate in the addictive process have been identified in some detail, although the story is not yet complete. The neuroanatomic and molecular bases of the withdrawal syndrome are less clearly understood.

Theoretical models, primarily from psychology, have been used either to predict risk behavior or to predict behavior change and, less frequently, maintenance of positive behavior change. Such models focus on the individual's perception of susceptibility, perception of benefits, constraints, and intentions to behave in particular ways (Fishbein et al., 1991). The concept of self-efficacy—the individual's belief that he or she can effectively carry out a desired behavior in a particular setting—is central to most models.

Despite their conceptual contributions, current theoretical models are limited in their ability to predict risk behavior for two main reasons. First, with respect to sexual behavior, the models are based on the assumption that sexual encounters are regulated by self-formulated plans of action, and that individuals are acting in an intentional and volitional manner when engaging in sexual activity. However, sexual behavior is often impulsive and, at least in part, physiologically motivated.

Second, the dominant theoretical models of behavior do not easily accommodate contextual personal and sociocultural variables such as gender, race/ethnicity, culture, and class. For example, gender roles and cultural values and norms influence the behavior of women and men and the nature of the relationships in which sexual activity occurs. Unsafe sexual practices often are not the result of a deficit of knowledge, motivation, or skill, but instead have meaning within a given personal and sociocultural context. A great deal of work remains to be done to better integrate theories of gender and culture with models of behavior change.

Additionally, models designed to explain or predict risk behavior

FRONT MATTER (R1-R18)

EXECUTIVE SUMMARY (1-38)

1 INTRODUCTION (39-44)

PART I RESEARCH FINDINGS AND OPPORTUNITIES (45-46)

2 UNDERSTANDING HIV TRANSMISSION (47-77)

3 UNDERSTANDING THE DETERMINANTS OF HIV RISK BEHAVIOR (78-123)

4 DISEASE PROGRESSION AND INTERVENTION (124-154)

PART II MANAGING THE AIDS RESEARCH PROGRAMS AT NIAAA, NIDA, AND NIMH (155-156)

5 THE CONTEXT OF AIDS PROGRAMS AT NIAAA, NIDA, AND NIMH (157-185)

6 RESEARCH FUNDING, PROGRAMS, AND PRIORITIES AT NIAAA, NIDA, AND NIMH (186-239)

7 LINKAGES BETWEEN RESEARCH AND SERVICES (240-256)

BIBLIOGRAPHY AND REFERENCES (257-296)

APPENDIXES (297-298)

A Grants Analysis Methodology (299-304)

B Abbreviations and Acronyms (305-308)

C Acknowledgments (309-314)

D Contributors (315-326)

INDEX (327-338)