Chapter V
Mental and behavioural disorders
(F00-F99)

Organic, including symptomatic, mental disorders
(F00-F09)

This block comprises a range of mental disorders grouped together on the basis of their having in common a demonstrable etiology in cerebral disease, brain injury, or other insult leading to cerebral dysfunction. The dysfunction may be primary, as in diseases, injuries, and insults that affect the brain directly and selectively; or secondary, as in systemic diseases and disorders that attack the brain only as one of the multiple organs or systems of the body that are involved.

Dementia (F00-F03) is a syndrome due to disease of the brain, usually of a chronic or progressive nature, in which there is disturbance of multiple higher cortical functions, including memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgement. Consciousness is not clouded. The impairments of cognitive function are commonly accompanied, and occasionally preceded, by deterioration in emotional control, social behaviour, or motivation. This syndrome occurs in Alzheimer's disease, in cerebrovascular disease, and in other conditions primarily or secondarily affecting the brain.

Use additional code, if desired, to identify the underlying disease.

F00* Dementia in Alzheimer's disease ( G30.-+ )
Alzheimer's disease is a primary degenerative cerebral disease of unknown etiology with characteristic neuropathological and neurochemical features. The disorder is usually insidious in onset and develops slowly but steadily over a period of several years.
F00.0* Dementia in Alzheimer's disease with early onset ( G30.0+ )
Dementia in Alzheimer's disease with onset before the age of 65, with a relatively rapid deteriorating course and with marked multiple disorders of the higher cortical functions.
Alzheimer's disease, type 2
Presenile dementia, Alzheimer's type
Primary degenerative dementia of the Alzheimer's type, presenile onset
F00.1* Dementia in Alzheimer's disease with late onset ( G30.1+ )
Dementia in Alzheimer's disease with onset after the age of 65, usually in the late 70s or thereafter, with a slow progression, and with memory impairment as the principal feature.
Alzheimer's disease, type 1
Primary degenerative dementia of the Alzheimer's type, senile onset
Senile dementia, Alzheimer's type
F00.2* Dementia in Alzheimer's disease, atypical or mixed type ( G30.8+ )
Atypical dementia, Alzheimer's type
F00.9* Dementia in Alzheimer's disease, unspecified ( G30.9+ )

F01 Vascular dementia
Vascular dementia is the result of infarction of the brain due to vascular disease, including hypertensive cerebrovascular disease. The infarcts are usually small but cumulative in their effect. Onset is usually in later life.
Includes: arteriosclerotic dementia
F01.0 Vascular dementia of acute onset
Usually develops rapidly after a succession of strokes from cerebrovascular thrombosis, embolism or haemorrhage. In rare cases, a single large infarction may be the cause.
F01.1 Multi-infarct dementia
Gradual in onset, following a number of transient ischaemic episodes which produce an accumulation of infarcts in the cerebral parenchyma.
Predominantly cortical dementia
F01.2 Subcortical vascular dementia
Includes cases with a history of hypertension and foci of ischaemic destruction in the deep white matter of the cerebral hemispheres. The cerebral cortex is usually preserved and this contrasts with the clinical picture which may closely resemble that of dementia in Alzheimer's disease.
F01.3 Mixed cortical and subcortical vascular dementia
F01.8 Other vascular dementia
F01.9 Vascular dementia, unspecified

F02* Dementia in other diseases classified elsewhere
Cases of dementia due, or presumed to be due, to causes other than Alzheimer's disease or cerebrovascular disease. Onset may be at any time in life, though rarely in old age.
F02.0* Dementia in Pick's disease ( G31.0+ )
A progressive dementia, commencing in middle age, characterized by early, slowly progressing changes of character and social deterioration, followed by impairment of intellect, memory, and language functions, with apathy, euphoria and, occasionally, extrapyramidal phenomena.
F02.1* Dementia in Creutzfeldt-Jakob disease ( A81.0+ )
A progressive dementia with extensive neurological signs, due to specific neuropathological changes that are presumed to be caused by a transmissible agent. Onset is usually in middle or later life, but may be at any adult age. The course is subacute, leading to death within one to two years.
F02.2* Dementia in Huntington's disease ( G10+ )
A dementia occurring as part of a widespread degeneration of the brain. The disorder is transmitted by a single autosomal dominant gene. Symptoms typically emerge in the third and fourth decade. Progression is slow, leading to death usually within 10 to 15 years.
Dementia in Huntington's chorea
F02.3* Dementia in Parkinson's disease ( G20+ )
A dementia developing in the course of established Parkinson's disease. No particular distinguishing clinical features have yet been demonstrated.
Dementia in:
· paralysis agitans
· parkinsonism
F02.4* Dementia in human immunodeficiency virus [HIV] disease ( B22.0+ )
Dementia developing in the course of HIV disease, in the absence of a concurrent illness or condition other than HIV infection that could explain the clinical features.
F02.8* Dementia in other specified diseases classified elsewhere
Dementia in:
· cerebral lipidosis ( E75.-+ )
· epilepsy ( G40.-+ )
· hepatolenticular degeneration ( E83.0+ )
· hypercalcaemia ( E83.5+ )
· hypothyroidism, acquired ( E01.-+ , E03.-+ )
· intoxications ( T36-T65+ )
· multiple sclerosis ( G35+ )
· neurosyphilis ( A52.1+ )
· niacin deficiency [pellagra] ( E52+ )
· polyarteritis nodosa ( M30.0+ )
· systemic lupus erythematosus ( M32.-+ )
· trypanosomiasis ( B56.-+ , B57.-+ )
· vitamin B 12 deficiency ( E53.8+ )

F03 Unspecified dementia
Presenile:
· dementia NOS
· psychosis NOS
Primary degenerative dementia NOS
Senile:
· dementia:
  · NOS
  · depressed or paranoid type
· psychosis NOS
Excludes: senile dementia with delirium or acute confusional state ( F05.1 )
senility NOS ( R54 )

F04 Organic amnesic syndrome, not induced by alcohol and other psychoactive substances
A syndrome of prominent impairment of recent and remote memory while immediate recall is preserved, with reduced ability to learn new material and disorientation in time. Confabulation may be a marked feature, but perception and other cognitive functions, including the intellect, are usually intact. The prognosis depends on the course of the underlying lesion.
Korsakov's psychosis or syndrome, nonalcoholic
Excludes: amnesia:
· NOS ( R41.3 )
· anterograde ( R41.1 )
· dissociative ( F44.0 )
· retrograde ( R41.2 )
Korsakov's syndrome:
· alcohol-induced or unspecified ( F10.6 )
· induced by other psychoactive substances ( F11-F19 with common fourth character .6)

F05 Delirium, not induced by alcohol and other psychoactive substances
An etiologically nonspecific organic cerebral syndrome characterized by concurrent disturbances of consciousness and attention, perception, thinking, memory, psychomotor behaviour, emotion, and the sleep-wake schedule. The duration is variable and the degree of severity ranges from mild to very severe.
Includes: acute or subacute:
· brain syndrome
· confusional state (nonalcoholic)
· infective psychosis
· organic reaction
· psycho-organic syndrome
Excludes: delirium tremens, alcohol-induced or unspecified ( F10.4 )
F05.0 Delirium not superimposed on dementia, so described
F05.1 Delirium superimposed on dementia
Conditions meeting the above criteria but developing in the course of a dementia (F00-F03).
F05.8 Other delirium
Delirium of mixed origin
F05.9 Delirium, unspecified

F06 Other mental disorders due to brain damage and dysfunction and to physical disease
Includes miscellaneous conditions causally related to brain disorder due to primary cerebral disease, to systemic disease affecting the brain secondarily, to exogenous toxic substances or hormones, to endocrine disorders, or to other somatic illnesses.
Excludes: associated with:
· delirium ( F05.- )
· dementia as classified in F00-F03
resulting from use of alcohol and other psychoactive substances ( F10-F19 )
F06.0 Organic hallucinosis
A disorder of persistent or recurrent hallucinations, usually visual or auditory, that occur in clear consciousness and may or may not be recognized by the subject as such. Delusional elaboration of the hallucinations may occur, but delusions do not dominate the clinical picture; insight may be preserved.
Organic hallucinatory state (nonalcoholic)
Excludes: alcoholic hallucinosis ( F10.5 )
schizophrenia ( F20.- )
F06.1 Organic catatonic disorder
A disorder of diminished (stupor) or increased (excitement) psychomotor activity associated with catatonic symptoms. The extremes of psychomotor disturbance may alternate.
Excludes: catatonic schizophrenia ( F20.2 )
stupor:
· NOS ( R40.1 )
· dissociative ( F44.2 )
F06.2 Organic delusional [schizophrenia-like] disorder
A disorder in which persistent or recurrent delusions dominate the clinical picture. The delusions may be accompanied by hallucinations. Some features suggestive of schizophrenia, such as bizarre hallucinations or thought disorder, may be present.
Paranoid and paranoid-hallucinatory organic states
Schizophrenia-like psychosis in epilepsy
Excludes: disorder:
· acute and transient psychotic ( F23.- )
· persistent delusional ( F22.- )
· psychotic drug-induced ( F11-F19 with common fourth character .5)
schizophrenia ( F20.- )
F06.3 Organic mood [affective] disorders
Disorders characterized by a change in mood or affect, usually accompanied by a change in the overall level of activity, depressive, hypomanic, manic or bipolar (see F30-F38), but arising as a consequence of an organic disorder.
Excludes: mood disorders, nonorganic or unspecified ( F30-F39 )
F06.4 Organic anxiety disorder
A disorder characterized by the essential descriptive features of a generalized anxiety disorder (F41.1), a panic disorder (F41.0), or a combination of both, but arising as a consequence of an organic disorder.
Excludes: anxiety disorders, nonorganic or unspecified ( F41.- )
F06.5 Organic dissociative disorder
A disorder characterized by a partial or complete loss of the normal integration between memories of the past, awareness of identity and immediate sensations, and control of bodily movements (see F44.-), but arising as a consequence of an organic disorder.
Excludes: dissociative [conversion] disorders, nonorganic or unspecified ( F44.- )
F06.6 Organic emotionally labile [asthenic] disorder
A disorder characterized by emotional incontinence or lability, fatigability, and a variety of unpleasant physical sensations (e.g. dizziness) and pains, but arising as a consequence of an organic disorder.
Excludes: somatoform disorders, nonorganic or unspecified ( F45.- )
F06.7 Mild cognitive disorder
A disorder characterized by impairment of memory, learning difficulties, and reduced ability to concentrate on a task for more than brief periods. There is often a marked feeling of mental fatigue when mental tasks are attempted, and new learning is found to be subjectively difficult even when objectively successful. None of these symptoms is so severe that a diagnosis of either dementia (F00-F03) or delirium (F05.-) can be made. This diagnosis should be made only in association with a specified physical disorder, and should not be made in the presence of any of the mental or behavioural disorders classified to F10-F99. The disorder may precede, accompany, or follow a wide variety of infections and physical disorders, both cerebral and systemic, but direct evidence of cerebral involvement is not necessarily present. It can be differentiated from postencephalitic syndrome (F07.1) and postconcussional syndrome (F07.2) by its different etiology, more restricted range of generally milder symptoms, and usually shorter duration.
F06.8 Other specified mental disorders due to brain damage and dysfunction and to physical disease
Epileptic psychosis NOS
F06.9 Unspecified mental disorder due to brain damage and dysfunction and to physical disease
Organic:
· brain syndrome NOS
· mental disorder NOS

F07 Personality and behavioural disorders due to brain disease, damage and dysfunction
Alteration of personality and behaviour can be a residual or concomitant disorder of brain disease, damage or dysfunction.
F07.0 Organic personality disorder
A disorder characterized by a significant alteration of the habitual patterns of behaviour displayed by the subject premorbidly, involving the expression of emotions, needs and impulses. Impairment of cognitive and thought functions, and altered sexuality may also be part of the clinical picture.
Organic:
· pseudopsychopathic personality
· pseudoretarded personality
Syndrome:
· frontal lobe
· limbic epilepsy personality
· lobotomy
· postleucotomy
Excludes: enduring personality change after:
· catastrophic experience ( F62.0 )
· psychiatric illness ( F62.1 )
postconcussional syndrome ( F07.2 )
postencephalitic syndrome ( F07.1 )
specific personality disorder ( F60.- )
F07.1 Postencephalitic syndrome
Residual nonspecific and variable behavioural change following recovery from either viral or bacterial encephalitis. The principal difference between this disorder and the organic personality disorders is that it is reversible.
Excludes: organic personality disorder ( F07.0 )
F07.2 Postconcussional syndrome
A syndrome that occurs following head trauma (usually sufficiently severe to result in loss of consciousness) and includes a number of disparate symptoms such as headache, dizziness, fatigue, irritability, difficulty in concentration and performing mental tasks, impairment of memory, insomnia, and reduced tolerance to stress, emotional excitement, or alcohol.
Postcontusional syndrome (encephalopathy)
Post-traumatic brain syndrome, nonpsychotic
F07.8 Other organic personality and behavioural disorders due to brain disease, damage and dysfunction
Right hemispheric organic affective disorder
F07.9 Unspecified organic personality and behavioural disorder due to brain disease, damage and dysfunction
Organic psychosyndrome

F09 Unspecified organic or symptomatic mental disorder
Psychosis:
· organic NOS
· symptomatic NOS
Excludes: psychosis NOS ( F29 )