PSYCHOLOGICAL ASSESSMENT AND DIAGNOSTIC TECHNIQUES

Abstract

This chapter provides a comprehensive overview of psychological assessment and diagnostic techniques as foundational components of evidence-based mental health practice. Psychological assessment is presented as a systematic process of gathering, integrating, and interpreting data to understand an individual’s cognitive, emotional, behavioural, and personality functioning. The chapter emphasizes that effective diagnosis is not a single test outcome but a multimethod, multisource evaluation guided by clinical reasoning and ethical standards. Key assessment tools are examined, including clinical interviews (structured, semi-structured, and unstructured), behavioural observations, cognitive and intelligence testing, personality inventories, neuropsychological measures, and symptom-specific rating scales. The chapter highlights widely used instruments such as the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) and the International Classification of Diseases (ICD-11) as primary diagnostic frameworks that guide classification and clinical decision-making across diverse settings. Emerging trends in psychological assessment are also reviewed, including digital assessment platforms, telehealth-based evaluations, computerized adaptive testing, and the integration of biological and neuroscientific data. The chapter concludes by reinforcing the importance of clinical judgment in synthesizing quantitative and qualitative findings to generate accurate diagnoses, inform treatment planning, and promote positive client outcomes.