INVESTIGATIONS
IN PSYCHIATRY
INTRODUCTION:
Psychiatrist depend more on the
clinical examination and the patient's signs and symptoms to make a diagnosis.
No laboratory tests in psychiatry can confirm or rule out diagnosis such as
schizophrenia, bipolar disorder, In clinical psychiatry laboratow tests can
help rule out potential underlying organic causes of psychiatric symptoms.
1.
LABORATORY TESTS
The use of diagnostic tests in
detecting physical illness in psychiatric patients:
Physical disorders are quite common,
and also these may cause or exacerbate psychiatric symptomatology. It has been
observed that many psychiatric patients with concomitant medical disorders have
high mortality rate.
A. Screening tests used include:
1.
Complete blood count (including peripheral smear and
ESR)
2.
Blood chemistry (electrolytes including calcium,
phosphorous, glucose, blood urea, creatinine, hepatic functions)
3.
Urine analysis
4.
ECG
5.
X-ray skull and chest
6.
Screening test for syphilis
7.
Thyroid function test (T3 resin uptake, T4 , TSH)
8.
Vitamin B 12 and folate levels
B. Supplementary Tests
·
When the commonly used tests are negative and an
organic cause is suspected-
·
CT scan
·
CSF examination
·
Stool test for occult blood
·
Urine and serum osmolality
·
Antinuclear antibodies
·
Drug screen (eg. Thin layer chromatography, gas
chromatography) Serum and urine copper levels
·
HIV testing
·
MRI
·
Blood or breath alcohol level
·
Heavy metal screening Blood levels of
medications
·
Serum ceruloplsmin
C. Special investigations in
psychiatry:
1. Electroencephalography (EEG):
It is recording of the electrical
activity of the brain, It records brain waves which are continuously varying in
frequency, form and amplitude.
2. Polysomnography (sleep studies):
EEG activity is recorded during
sleep and it is usually performed at night. Several disorders associated with
psychiatric symptoms like sleep apnoea, narcolepsy, hypersomnia, seizure
disorders, headaches, sexual dysfunction; insomnia can be evaluated by the
sleep laboratory
3. CT scan:
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