Abnormal psychology

Abnormal psychology studies the nature of psychopathology, its causes, and its treatments. Of course the definition of what constitutes 'abnormal' has varied across time and across cultures. Individuals also vary in what they regard as normal or abnormal behavior.

Nosology

DSM-IV TR

In North America the 'bible' of abnormal psychology and psychiatry is the Diagnostic and Statistical Manual of the American Psychiatric Association.The current version of the book is known as DSM IV-TR. It lists a set of disorders and provides detailed descriptions on what constitutes a disorder such as Major Depression or Anxiety Disorder. It also gives general descriptions of how frequent the disorder occurs in the general population, whether it is more common in males or females and other such facts. The diagnostic process uses five dimensions called 'axes' to ascertain symptoms and overall functioning of the individual. These axes are as follows:

• Axis I - Particular clinical syndromes
• Axis II - Personality disorders
• Axis III - General medical conditions
• Axis IV - Psychosocial/environmental problems
• Axis V - Global assessment of functioning (often referred to as GAF)

ICD-10

The major international nosologic system for the classification of mental disorders can be found in the most recent version of the International Classification of Diseases, 10th revision (ICD-10). The ICD-10 has been used by World Health Organization (WHO) Member States since 1994. Chapter five covers some 300 "Mental and behavioural disorders." The ICD-10's chapter five has been influenced by APA's DSM-IV and there is a great deal of concordance between the two. WHO maintains free access to the ICD-10 Online . Below are the main categories of disorders:

• F00-F09 Organic, including symptomatic, mental disorders
• F10-F19 Mental and behavioural disorders due to psychoactive substance use
• F20-F29 Schizophrenia, schizotypal and delusional disorders
• F30-F39 Mood [affective] disorders
• F40-F48 Neurotic, stress-related and somatoform disorders
• F50-F59 Behavioural syndromes associated with physiological disturbances and physical factors
• F60-F69 Disorders of adult personality and behaviour
• F70-F79 Mental retardation
• F80-F89 Disorders of psychological development
• F90-F98 Behavioural and emotional disorders with onset usually occurring in childhood and adolescence
• F99 Unspecified mental disorder