Clinical Psychology

debilitating. They typically have their onset in late
adolescence or early adulthood, and thereby limit the
individual’s opportunities for achieving independence.
The fact that psychotic disorders tend to have their
onset during a specific developmental stage is now
assumed to reflect the role of brain maturation pro-
cesses in the genesis of these illnesses. Our main
research objectives are to enhance the prediction of
risk for psychosis in youth and to shed light on the
neural mechanisms that are involved in the emergence
of psychoses. In particular, we are interested in the way
that normative brain changes in adolescence may go
awry in youth at risk for psychosis. We are pursuing the
hypothesis that hormones, especially stress hormones,
may be playing an important role in these processes.
In recent years we have expanded our research on
the biological response to stress and are pursuing a line
of investigation aimed at elucidating the role of bio-
logical stress response systems, particularly the
hypothalamic-pituitary-adrenal (HPA) axis. This system
governs the release of stress hormones, including cor-
tisol in primates, and has pervasive effects on brain
function. It appears that the adolescent/early adult
period is a critical stage in the development of the HPA
axis, and this may be playing a role in triggering the
manifestation of vulnerability for psychosis during this
period.

What are the future trends you see for clinical
psychology?
Since I entered the field in the 1970s, psychology in
general has broadened its focus to encompass the com-
plex interactions between behavioral and biological
factors. The same trend is apparent in clinical psychol-
ogy. As research findings in psychology and neurosci-
ence have accumulated, it has become increasingly
apparent that we cannot separate biology and psychol-
ogy. The notion that biological factors (e g., genetics,
hormones etc.) influence psychological functioning has
been widely accepted by both the general public and
behavioral scientists. But the pervasive role of psycho-
logical factors in altering biological processes, most
notably brain function, has only been recognized by
scientists in the past few decades. Numerous studies of
both animals and humans have demonstrated that psy-
chosocial factors alter brain processes, sometimes trig-
gering permanent changes. This has led us to a more
complex and accurate view of the intricate interactions
between psychological and biological factors in deter-
mining the course of human development. Thus,

university training in clinical psychology now includes a

greater emphasis on the interface among behavioral

science, neuroscience, and genetics. The knowledge

generated in all of these fields is important for research

progress in the field of mental health.

How will the field evolve as our ability to assess

neurodevelopmental factors increases in sophistication?

As our scientific understanding of normal brain devel-

opment increases, so will our opportunities to identify

the neurodevelopmental processes involved in mental

disorders. I expect that training in clinical psychology

will be keep pace with advances in the field, and future

generations of clinical psychology researchers will be

equipped to make significant contributions to research

on the causes and treatment, and perhaps even pre-

vention, of mental disorders.

Elaine Walker

Elaine Walker

DIAGNOSIS AND CLASSIFICATION OF PSYCHOLOGICAL PROBLEMS 141