hello sir., headache is a symptom for many diseases. and it s non specific symptom. (means not easy to find out the disease with only this symptom, needs further evaluation). it has a huge range of diseases from simple tension headache to life-threatening cerebral infections. but don t panic by my statements. most of the time it s cause is benign. as the information you have given is not adequate to give you the exact reason for your headache. need to know your age, gender, and your any other illness or medications. most of the clinicians would suggest you to do CT scan to rule out life threatening diseases first. anyway first make sure that you are not having any stress.(like decreased sleep, eye strain)I would suggest for an eye checkup for refractory error as it s very common cause and goes unnoticed. and next is response to analgesics.try simple analgesic like paracetemol and if your headache goes off then don t worry it s just a tension headache. if your headache is associated with earache then it could be an ear problem(like ear infection) for which I would suggest you to consult ENT expert for ear examination. if your headache is associated with nausea and vomting or if it s confined only to one half of your head then it s a migraine headache for which too analgesics will be enough most of the times. if it persists then we will check for other problems.as you have mentioned it you are having mood disorders get it checked with a psychiatrist(only if you think it s significant). hope this helps you.