A clinical psychologist is required to have received a PhD or PsyD before they may practice, which includes 4 to 6 years in graduate school and at least one year spent in clinical internships. In approaching human problems clinical psychologists use a broad approach consisting of assessment, diagnosis, consultation, treatment, program development, administration and research. Clinical psychologists seek to develop and use a classification system of abnormal behaviour, to understand abnormal behaviour and its causes, and to find cures for abnormal behaviour.
