What is a psychological disorder?
Psychologists use careful criteria to decide when thoughts, feelings, or behaviours become a disorder. This lesson is for learning about psychology, not for diagnosing yourself or anyone else; if you are struggling, talk to a qualified professional.
Defining disorder
A psychological disorder generally involves significant disturbances in thinking, emotion, or behaviour that cause distress or impair daily functioning. Being unusual is not enough: a behaviour must also be harmful or disruptive, and cultural context matters, since what is typical in one culture may seem odd in another.
The DSM
In the United States, clinicians use the Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association and now in its fifth edition with a text revision. It lists criteria for each disorder so that diagnoses are more consistent. The World Health Organization's International Classification of Diseases (ICD) is used in much of the world.
Explaining disorders
The biopsychosocial model holds that disorders result from interacting biological factors (genes, brain chemistry), psychological factors (thought patterns, stress), and social factors (relationships, culture, poverty). The diathesis-stress model says a disorder appears when an underlying vulnerability is triggered by stressful experiences.
Flashcard
The manual clinicians use to diagnose psychological disorders
Check your understanding
Two siblings share a genetic risk for depression, but only the one who experiences severe stress develops it. Which model best explains this?