# 246 - 6E68 Secondary personality change

# 6E68 Secondary personality change

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders
Potentially explanatory medical conditions
Brain disorders and general medical conditions that have been shown to be capable of producing 
neurocognitive syndromes include:
• diseases of the nervous system (e.g. adrenoleukodystrophy, cerebral arteritis, seizures);
• certain infectious or parasitic diseases (e.g. cryptococcosis, Lyme borreliosis, neurosyphilis);
• diseases of the blood or blood-forming organs (e.g. sickle cell disorders);
• diseases of the digestive system (e.g. hepatic failure, intestinal malabsorption);
• diseases of the genitourinary system (e.g. renal failure);
• diseases of the immune system (e.g. eosinophilia, systemic lupus erythematosus);
• endocrine, nutritional or metabolic diseases (e.g. hypercalcaemia, hypo- or hyperglycaemia, 
hypothyroidism);
• neoplasms (e.g. neoplasms of brain).
Secondary personality change
Essential (required) features
• The presence of personality disturbance (e.g. marked apathy, indifference, suspiciousness, 
paranoid ideation, disinhibition) that represents a change from the individual’s previous 
characteristic personality pattern is required for diagnosis.
• The personality change is judged to be the direct pathophysiological consequence of a 
medical condition, based on evidence from the history, physical examination or laboratory 
findings. This judgement depends on establishing the following.
• The medical condition is known to be capable of producing the observed symptoms.
• The course of the personality change (e.g. onset, remission, response of the personality 
disturbance to treatment of the etiological medical condition is consistent with causation 
by the medical condition).
• The symptoms are not better accounted for by delirium, dementia, another mental 
disorder (e.g. personality disorder, impulse control disorders, secondary impulse control 
or addictive behaviour syndrome) or the effects of a medication or substance, including 
withdrawal effects.
• The symptoms are sufficiently severe to be a specific focus of clinical attention.
6E68
Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere

673
Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere
Boundaries with other disorders and conditions (differential diagnosis)
Boundary with personality disorder and personality difficulty
Establishing the presence of a potentially explanatory medical condition that can cause personality 
change and the temporal relationship between the medical condition and the personality change 
is critical in diagnosing secondary personality change. Personality is relatively stable over time, 
and personality disorder and personality difficulty are usually evident by early adulthood. In 
contrast, secondary personality change has its onset following or coincident with the onset of a 
medical condition that is judged to be its direct pathophysiological cause, and is characterized 
by the emergence of personality traits that represent a change from the individual’s previous 
characteristic personality pattern (e.g. marked apathy, indifference, suspiciousness, paranoid 
ideation, disinhibition).
Boundary with dementia
Personality change can occur in the context of dementia, which is characterized by a decline from 
a previous level of cognitive functioning with impairment in two or more cognitive domains (e.g. 
memory, executive functions, attention, language, social cognition and judgement, psychomotor 
speed, visuoperceptual or visuospatial abilities). In secondary personality change, the emergence of 
personality traits that represent a change from the individual’s previous characteristic personality 
pattern is not accompanied by marked cognitive impairment. The emergence of problematic 
personality features in the context of dementia may be recorded using one of the behavioural or 
psychological disturbances in dementia specifiers (e.g. apathy in dementia, agitation or aggression 
in dementia, disinhibition in dementia), if applicable. If the personality changes are judged to 
be due to the same medical condition as is causing the dementia, an additional diagnosis of 
secondary personality change is not warranted.
Boundary with personality change caused by substances or medications, including 
withdrawal effects
When establishing a diagnosis of secondary personality change, it is also important to rule out 
the possibility that a substance or medication is causing the personality disturbance instead of 
– or in addition to – an underlying medical condition. This involves first considering whether 
any of the medications being used to treat the medical condition are known to cause personality 
disturbance at the dose and duration at which it has been administered (e.g. apathy due to chronic 
cannabis use, paranoid ideation due to chronic stimulant use). Second, a temporal relationship 
between the medication use and the onset of the personality disturbance should be established 
(i.e. the personality change began after administration of the medication and/or remitted once the 
medication was discontinued). If the intensity or duration of the personality change is substantially 
in excess of symptoms that are characteristic of the substance-specific intoxication or withdrawal 
syndrome, then other disorder due to use of substances is the appropriate diagnosis, applying the 
appropriate category corresponding to the substance involved.
Boundary with secondary impulse control or addictive behaviour syndrome
Personality changes may include symptoms of disordered impulse control or addictive behaviours. 
If the personality changes judged to be the direct pathophysiological consequence of a medical 
condition are restricted to increased impulsivity or addictive behaviours, then secondary 
impulse control or addictive behaviour syndrome is the appropriate diagnosis rather secondary 
personality change.
Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere