Introduction

Stress is a term used widely – and perhaps too loosely – in popular books, in the media, and in daily life. From the perspective of someone who studies stress, it is difficult not to notice the differences in meaning and understandings of stress now in common use. When the explanation of some problem becomes unclear, or complex, or mysterious, stress is invoked: “It must be stress.” When someone says “I feel stressed,” they are in fact referring to distress, describing the behavioral response to stressful conditions, usually manifest as a mixture of depression and anxiety.

The life course is a path. For most people, this path is far from straight. We use the ideas of trajectories and turning points to divide the life course into complementary parts. A trajectory is the continuation of a direction. It is the inertia in our lives that results from the sum of the forces that propel us toward a destination. A turning point is a disruption in a trajectory, a deflection in the path. Indeed, the essential characteristic of a turning point is that it changes the direction of a trajectory.

The concepts of trajectories and turning points require each other in order to be understood. If we concentrate on trajectories, it leads naturally to the question: What intervenes and disturbs these trajectories? What pushes people away from the path they were on? What puts people back on their former path? Similarly, we cannot conceive of turning points without defining the trajectory as the “norm.” To see an event or a transition as a turning point requires time, stability, and an established baseline.

We think most clearly of turning points as “events,” as crucially important moments in a life history. But turning points need not be dramatic events, or unusual events, or even a single discrete event. Turning points may be difficult to see as they are occurring, because they are only recognized to be turning points as time passes and as it becomes clear that there has been a change in direction.

Introduction

The word “stress” has come to have many connotations. Whereas research on life stress focused almost exclusively on life change events through the 1970s, research and theory since then have resulted in a differentiated stress universe, with multiple stress concepts (Wheaton 1994). Beyond life events, one can identify at least five other types of stressors, including chronic stressors (Pearlin 1989; Wheaton 1983), daily hassles (Kanner et al. 1981), macrosystem stressors such as economic downturns (Dooley & Catalano 1984); “nonevents,” that is, the non-occurrence of expected events (Gersten et al. 1974); as well as various forms of childhood and adult traumas, considered individually or collectively (Cadoret et al. 1990; Garmezy 1983; Kessler et al. 1995; Rutter & Quinton 1977; Terr 1991).

In Chapter 2 of this volume, Kessler and his colleagues explored their ongoing research program on childhood adversities. These childhood adversities overlap considerably with the traumatic stressors studied in this chapter. Both refer to serious, often overwhelming, stressful experiences. The term “adversity” clearly allows for both discrete traumatizing experiences and more chronically difficult life conditions. In this chapter, we consider both types of stressors.

The potential importance of traumatic events and situations for long-term mental health is hardly in doubt. Research attention to such traumas has been intense in recent years, especially for certain “core” traumas thought to be crucial in setting long-term trajectories of mental health problems.