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