Smoking and mental health - NCSCT

1
Mental disorders
1.1 What is a mental disorder?
Mental health problems, referred to in this report as mental disorders, are
common in the general population and include depressive and anxiety disorders,
eating and somatisation disorders, and psychotic disorders (schizophrenia,
bipolar disorder and related disorders such as schizoaffective psychosis).
Different mental disorders are characterised by different symptoms (see sections
1.3–1.8) and are defined less by the occurrence of specific symptoms (subjective
complaints) or signs (behaviours) than by their severity or clustering to the
extent that causes distress and interference with personal function. 1 The
distinction of depression from ordinary sadness, or schizophrenia from the
paranoid delusional thinking and auditory hallucinations that occur in up to 8%
of healthy people, 2 is somewhat arbitrary, as indeed is the case in other areas of
medicine, eg in determining the levels of blood pressure or blood sugar that
define hypertension or diabetes. Indeed, some mental health research and clinical
practice involve use of self-report symptom scales with different cut-offs used to
distinguish probable mild disorders from more severe disorders. However, the
use of binary distinctions to differentiate disorder from normality is common to
most areas of medicine and reflects the importance of clinical diagnoses in
guiding healthcare planning, and the delivery of prognostic and treatment advice
in clinical management.
For mental disorders, the main internationally recognised diagnostic
classifications currently in use are the World Heath Organization’s (WHO’s)
International classification of diseases, 10th revision (ICD-10) 1 and the
American Diagnostic and statistical manual of mental disorders, 4th edition
(DSM-IV), 3 both of which are currently being revised and updated (to
ICD-11 and DSM-V respectively). The term ‘mental disorder’ in these
classifications also includes personality disorder (see below), dementia
(a degenerative disorder that is usually treated within mental health services
and is included in this report), and alcohol and drug disorders and nicotine
dependence. Primary alcohol and substance misuse disorders are not
specifically addressed in this report because they are beyond its scope, but
they are also associated with smoking and are discussed in the context of
© Royal College of Physicians 2013 1