Psychological medicine

Disorders due to a General Medical Condition

  • Psychiatric symptoms occur in a wide range of medical conditions
  • Neurological: 
    • Degenerative: Parkinson‟s, Huntington‟s, Wilson‟s ® depression, dementia, psychosis
    • Epilepsy: 30 – 50 % have psychiatric illness at some stage, can be due to medication
    • Brain tumours: especially frontal lobe or limbic system
    • Head injury
    • Demyelinating disorders: eg MS
  • Infectious: 
    • Herpes simplex encephalitis ® changed personality, psychosis
    • Rabies, syphilis, CJD, Kuru (in PNG)
    • HIV
  • Autoimmune: Systemic lupus erythmatosus: eventually 50% have psych symptoms
  • Endocrine: 
    • Hyperthyroid ® confusion, anxiety, agitated depression, manic, delusions, with weakness and muscle loss 
    • Hypothyroid ® if severe then hypomania, depression, hallucinations 
    • Hypercalcaemia (due to PTH disorder) ® delirium, changed personality, apathy, ¯cognitive function 
    • Hypocalcaemia (due to PTH disorder) ® delirium, changed personality, eventually tetany
    • Hypoadrenocorticism (Addison‟s) ® apathy, depression
    • Hyperadrenocorticism (Cushing‟s) ® agitated depression
    • Total pituitary failure ® hypothyroid and hypoadrenocorticism
  • Metabolic: 
    • Hepatic encephalopathy ® ¯memory, ¯LOC, changed personality
    • Uraemia encephalopathy: renal failure ® ¯memory, ¯orientation, ¯LOC
    • Hypoglycaemia: agitation/restlessness 
    • Ketoacidosis ® easy fatigue 
    • Acute intermittent porphyria ® ­porphyrins (components of haemoglobin synthesis): acute colicky abdominal pain, motor polyneuropathy, psychosis, anxiety, insomnia, lability of mood, depression. Barbiturates absolutely contraindicated. 0.2 – 0.5 % psych patients have undiagnosed porphyria 
  • Nutritional:
    • Niacin deficiency
    • Thiamine deficiency 
    • B12 deficiency ® neuro degeneration ® depression, irritability, moodiness
  • Toxins:
    • Mercury: depression, irritability, psychosis, tremour, weakness
    • Lots of others
  • Cancers Eg carcinoma of the pancreas
  • Medication:
    • Mood disturbances from: stimulants, steroids, L-dopa, etc 
    • A previous condition (eg major depressive disorder) can be triggered by medication with the capacity to cause depressive symptoms