Psychological assessments are extremely important within the realm of psychology and they utilise several methods of assessing an individual’s cognitive thinking, behaviour, personality, and other mental faculties to determine or diagnose any conditions for which they need psychological treatment.
If so, using the information and data that the psychological assessment has produced, an appropriate treatment will be determined by a psychologist with a view to returning the client to a level of mental health which equates to a positive outcome for the individual.
In principle, a psychological assessment is no different to any other kind of medical assessment where the evidence is used to prescribe a course of treatment. For example, if a patient told their doctor they were having trouble breathing, tests would be carried out with regards to their respiratory system and the results would be used by the doctor to identify appropriate treatment.
That is the general basis upon which psychological assessments are performed, although within that wide scope there are multiple other purposes that they can be used for.