# 243 - 6E65 Secondary dissociative syndrome

# 6E65 Secondary dissociative syndrome

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Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere
Secondary dissociative syndrome
Essential (required) features
• The presence of prominent dissociative symptoms (e.g. depersonalization, derealization, 
dissociative amnesia, a marked alteration in the individual’s normal sense of personal 
identity) is required for diagnosis.
• The symptoms are 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 dissociative symptoms (e.g. onset, remission, response of the dissociative 
symptoms 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. dissociative disorders, disorders specifically associated with stress, schizophrenia and 
other primary psychotic disorders) or the effects of a medication or substance, including 
withdrawal effects.
• The symptoms are sufficiently severe to be a specific focus of clinical attention.
Boundaries with other disorders and conditions (differential diagnosis)
Boundary with dissociative disorders
Determining whether dissociative symptoms are due to a medical condition as opposed to 
manifestations of a primary mental disorder is often difficult because the clinical presentations 
may be similar. Establishing the presence of a potentially explanatory medical condition that can 
cause dissociative symptoms and the temporal relationship between the medical condition and 
the dissociative symptoms is critical in diagnosing secondary dissociative syndrome.
Boundary with dissociative symptoms caused by substances or medications, 
including withdrawal effects
When establishing a diagnosis of secondary dissociative syndrome, it is important to rule out the 
possibility that a medication or substance is causing the dissociative symptoms 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 dissociative symptoms 
at the dose and duration at which it has been administered. Second, a temporal relationship 
between the medication use and the onset of the dissociative symptoms should be established 
(i.e. the dissociative symptoms began after administration of the medication and/or remitted 
once the medication was discontinued). The same reasoning applies to individuals with a medical 
condition and dissociative symptoms who are also using a psychoactive substance known to 
cause dissociative symptoms, in the context of either intoxication or withdrawal (e.g. amnesia 
due to ketamine or phencyclidine intoxication, depersonalization due to dextromethorphan 
intoxication).
6E65
Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere