​Differential diagnosis of anatomic defects causing diaphragmatic dysfunction are : 
-congenital causes
-acquired causes

​Differential diagnosis of decreased in dehydro -3- epiandrosterone is : 
-menopause 

​Differential diagnosis of increased in dehydro-3-epiandrosterone are :
-Adrenal cortex tumours
-ovarian tumours
-polycystic ovaries 
-anovulation 
-hyperprolactinemia 
-androgen producing tumour 
-adrenogenital syndrome 
-hirsutism 
-hyperprolactinemia 

​Differential diagnosis of malnutrition causing depression are : 
-pellagra
-vitamin B12 deficiency 

​Differential diagnosis of infections causing depression are : 
-influenza 
-HIV infection 
-viral hepatitis 
-mononucleosis 
-syphilis 

​Differential diagnosis of neurological disorders causing depression are : 
-frontal brain lesion 
-epilepsy 
-stroke 
-multiple sclerosis 
-subdural hematoma
-Huntington’s disease
-Alzheimer’s disease
-Parkinson’s disease
-brain tumour 

​Differential diagnosis of endocrine or metabolic disorders causing depression are : 
-chronic renal failure 
-dialysis 
-pernicious anemia 
-diabetes mellitus 
-hypokalemia 
-hyponatremia 
-hypercalcemia 
-Addison’s disease
-hyperparathyroidism 
-Cushing’s syndrome 
-thyrotoxicosis 
-hypothyroidism 

​Differential diagnosis of drugs / toxins causing depression are : 
-sulfonamide 
-analgesic 
-antibiotic 
-alcohol abuse 
-reserpine 
-tranquilizer withdrawal 
-propanolol 
-procainamide 
-phenylbutazone 
-oral contraceptive 
-L dopa 
-methyldopa 
-isoniazid 
-indomethacin 
-H2 Blockers 
-griseofulvin 
-ethionamide 
-digitalis 
-corticosteroids 
-cocaine 
-clonidine 
-antihypertensive 

​Differential diagnosis of depression are : 
-drugs
-toxins
-infections 
-neurological disorders
-endocrine or metabolic disorders 
-malnutrition 
-parturition 
-pancreatic cancer 
-steroid withdrawal therapy 
-postoperative 
-myocardial infarction 

​Differential diagnosis of hypomelanosis / depigmentation are : 
-thyroid disease
-diabetes mellitus 
-vitiligo 
-anaemia 
-congenital 
-Nevus depigmentation 
-moles 
-piebaldism 
-post inflammatory hypomelanosis
-scleroderma
-tines versicolor
-albinism 
-oculocutaneous albinism 
-sarcoidosis 
-tuberous sclerosis
-psoriasis 
-Vogt Kayanagi Harada Syndrome 
-leprosy 
-secondary syphilis
-collagen vascular disease
-neoplasm 
-varicosis 
-candidiasis 
-syringomyelia 
-myasthenia gravis 
-dysgammaglobulinemia 
-thrombopenia 
-metabolic causes