2. Introduction
• Investigations are useful to detect alterations
in biologic functions and detect and to screen
for medical disorders that cause psychiatric
symptoms
• Classifications of the investigations
Routine investigations
Electrophysiological tests
Brain imaging tests
3. • Laboratory tests are included in a psychiatric
evaluation:
1) When they are necessary to establish or
exclude a diagnosis.
2) To aid in the choice of treatment.
3) To monitor treatment effects or side
effects.
4. No laboratory test in psychiatry can confirm or
rule out a diagnosis
Psychiatrists depend more on history, MSE,
and clinical examination to make a diagnosis
5. Routine investigations
• FHG- treatment with clozapine causes
leukopenia and agranulocytosis. Lithium is
associated with leucocytosis
• RFT- treatment with lithium
• LFT- indicated for all alcoholic patients or
those using carbamazepine, valproate &
benzodiazepines
6. Cont...
• Serum electrolytes- Dehydration, treatment
with carbamazepine, antipsychotics, lithium
• RBS- routine screen for those above 35 yrs of
age. Schizophrenia is known to cause insulin
resistance. Clozapine and olanzapine
• Thyroid function test: Depression, treatment
with lithium, antidepressants, ECT,
antipsychotics
• HIV testing: IV drugs users, suggestive sexual
history, and Dementia
• VDRL
8. Cont...
• Drug level estimation: tests for therapeutic
blood levels, for toxic blood levels,& for
testing drug compliance. Examples: lithium
(0.6-1.6mEq/l), haloperidol (8-18mEq/l)
9. Psychological tests
• Conducted by a clinical psychologists trained in
administration, and scoring of these procedures
• Instruments for assessment of symptoms:
Brief psychiatric rating scale
Psychiatric symptoms checklist
Anxiety self-rating scale
Hamilton anxiety scale
Beck’s depression scale
