Introduction

In the last two decades cognitive-clinical psychology has made impressive gains in the scope of its application to diverse clinical disorders, the complexity of its theoretical formulations, and the sophistication of its research methodology. If one were to compare current cognitive theory, research and treatment with the earliest writings of Beck (1967), Ellis (1962), Meichenbaum (1977), Rehm (1977) and Mahoney (1974), there can be little doubt that we have come a long way from those first forays into the cognitive basis of psychological disorders. If one ever questioned whether cognitive therapy (CT) represented a paradigmatic shift in clinical psychology (Wilson, 1978), a look back over the last 20 or 30 years of research and treatment advances should dispel any doubt.

As evident from the chapters in the current volume, correlational and experimental investigations into the cognitive basis of clinical disorders represents a prominent research perspective that is evident across a wide range of psychological problems. Moreover, the basic elements of CT and cognitive-behavioral therapy (CBT) have been applied to a diverse group of disorders in children, adolescents, and adults. We have a much better understanding of the cognitive concomitants of certain clinical disorders, and of the role of cognition in the etiology, persistence, and severity of disorders. The more scientific and rigorous experimental methodology of information processing has been employed to test various cognitive hypotheses.