Organic Mental Syndromes (Organic Causes of Psychiatric Symptoms)
Organic Mental Syndromes (Organic Causes of Psychiatric Symptoms)
Organic Mental Syndromes (Organic Causes of Psychiatric Symptoms)
Introduction:
The term ‘organic mental disorder/syndrome’ in psychiatry is used when there is a ‘disease of the body’ which present with psychiatric symptoms. In contrast, ‘functional mental disorders’ are considered to be ‘disease of the mind’. Classifying psychiatric disorders in this way is becoming outdated now that more is known about the ‘organic’ basis of functional illnesses, such as abnormal brain structure in schizophrenia. However, the term organic is still commonly used in clinical practice and communication and is included in the ICD 10.
Patients with organic disease can present with psychiatric symptoms. There are several ways this may occur,
1. Psychiatric symptoms of organic disorders:
Table 1 shows some of the organic illnesses, in which psychiatric symptoms occur as a direct result of the organic disease process.
Neurological
Endocrine
Other
P.Drugs
Depression
-Most dementias (especially vascular and Huntington’s) -Parkinson’s disease -Multiple sclerosis -Neurosyphilis
-Hypothyroidism -Cushing’s syndrome -Hypopituitarism -hyperparathyroidism -Addison’s disease
-Anaemia -infections -Carcinomatosis -Prophyria
-Corticosteroids -?-blockers -calcium channel blockers -L-dopa – OCP
Elation or Hypomania /Mania
-Multiple sclerosis -Neurosyphilis -TLE
-Cushing’s syndrome
-Carcinoma -CNS infections
-Corticosteroids -Antidepressants
Anxiety
-Parkinson’s disease -CVA -Brain injury
-Hyperthyroidism -Hypoglycemia -Phaechromocytoma
-Anaemia –
-SSRI Antidepressants -Anticonvulsants
Psychosis
-Huntington’s disease -Multiple sclerosis – Space occupying lesion -CNS infection
-Hyperthyroidism -Cushing’s disease
-SLE -Acute prophyria
-Corticosteroids -?-blockers -L-dopa -Sympathomimetics
ICD 10 classifies such episodes as ‘other mental disorders due to brain damage and dysfunction and physical disease’. By ‘other mental disorders’, it means disorders other than dementia, amnesic syndrome and delirium which are also due to brain damage and dysfunction or physical diseases. It splits theses other mental disorders into subgroups, depending on the nature of the psychiatric symptoms caused by the organic disorder. Examples of these include:
Organic hallucinosis Organic delusional disorder Organic mood disorder Organic anxiety disorder
In term of assessment, the possibility of an organic cause should always be kept in mind when assessing patients with psychiatric symptoms. There may be clues that patient has an organic disorder, some factors which suggest an organic cause of psychiatric symptoms are:
Ø Failure to respond to treatment Ø Different to previous psychiatric presentations Ø Abnormal physical examination Ø No clear aetiology Ø Other symptoms of organic illness Ø Atypical psychiatric presentation
As an example, think of differential diagnosis of a patient with anxiety an breathlessness. These symptoms are often caused by panic disorder. However, it would be important to look for symptoms and signs of organic disorders known to cause anxiety. For instance, the patient might also show evidence of heart intolerance and brisk deep tendon reflexes, in which case hyperthyroidism should be considered. For instance, if their anxiety was mild and seemed to be secondary to their breathlessness, a cardiac or respiratory cause should be considered.
An unusual presentation should also lead one to suspect a medical cause. For instance, first onset panic disorder would be very unusual in a 50-year-old man with no previous psychiatric history and no recent stresses or adverse life events. With such a presentation, organic causes should be vigorously investigated (not just the routine).
Recognition of medical disorders presenting in this way is clearly important as the patient will not usually
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