Clinical psychology

is an integration of science, theory, and clinical knowledge for the purpose of understanding,
preventing, and relieving psychologically-based distress or dysfunction and to promote subjective
well-being and personal development.^ Central to its practice are psychological assessment, problem
formulation, and psychotherapy, although clinical psychologists also engage in research, teaching,
consultation or forensic testimony.^ In many countries, clinical psychology is a regulated mental
health profession.

The field is generally considered to have begun in 1896 with the opening of the first psychological
clinic at the University of Pennsylvania by Lightner Witmer. In the first half of the 20th century,
clinical psychology was focused on psychological assessment, with little attention given to
treatment. This changed after the 1940s when World War II resulted in the need for a large increase
in the number of trained clinicians.

An important area of expertise for many clinical psychologists is psychological assessment, and
there are indications that as many as 91% of psychologists engage in this core clinical practice.
Such evaluation is usually done to gain insight into and forming hypotheses about psychological or
behavioural problems. As such, the results of such assessments are usually used to create
generalized impressions (rather than diagnoses) in service to informing treatment planning. Methods
include formal testing measures, interviews, reviewing past records, clinical observation, and
physical examination.

There exist hundreds of various assessment tools, although only a few have been shown to have both
high validity (test actually measures what it claims to measure) and reliability (consistency). We
can distinguish among others the following categories:
  * Intelligence & achievement tests are designed to measure certain specific kinds of cognitive
functioning (often referred to as IQ) in comparison to a control group. These tests attempt to
measure such traits as general knowledge, verbal skill, memory, attention span, logical reasoning,
and visual/spatial perception.
  * Personality tests aim to describe patterns of behaviour, thoughts, and feelings. They generally
fall within two categories: objective and projective. Objective tests are based on restricted
answers—such as yes/no, true/false, or a rating scale—which allow for the computation of scores
that can be compared to a normative group. Projective tests, such as the Rorschach inkblot test,
allow for open-ended answers.
  * Neuropsychological tests consist of specifically designed tasks used to measure psychological
functions known to be linked to a particular brain structure or pathway. They are typically used to
assess impairment after an injury or illness known to affect neurocognitive functioning.
  * Clinical observation – Clinical psychologists are also trained to gather data by observing
behaviour. The clinical interview is a vital part of the assessment, even when using other
formalized tools, which can employ either a structured or unstructured format. Such assessment
looks at certain areas, such as general appearance and behaviour, mood and affects, perception,
comprehension, orientation, insight, memory, and content of the communication.


Psychotherapy

involves a formal relationship between professional and client (usually an individual, couple,
family, or small group) that employs a set of procedures intended to form a therapeutic alliance,
explore the nature of psychological problems, and encourage new ways of thinking, feeling, or
behaving.

Although there are many recognized therapeutic orientations, their differences can often be
categorized on two dimensions: insight vs. action and in-session vs. out-session.
  * Insight – emphasis is on gaining a greater understanding of the motivations underlying one's
thoughts and feelings (e.g. psychodynamic therapy)
  * Action – focus is on making changes in how one thinks and acts (e.g. solution focused therapy,
cognitive behavioural therapy)
  * In-session – interventions focus on the here-and-now interaction between client and therapist
(e.g. humanistic therapy, Gestalt therapy)
  * Out-session – a large portion of therapeutic work is intended to happen outside of session
(e.g. bibliotherapy, rational emotive behaviour therapy)

The methods used are also different in regards to the population being served as well as the
context and nature of the problem.