Life science student here. I am also here to discuss about mental illness and mental health as a patient, although I view everything with a scientific lens.


No, not every disorder or disease is a chemical imbalance. It can be anything ranging from injury to infection to genetic disorders to natural response to unfavorable conditions. It is not exactly known why brain disorders are caused (although there is sufficient evidence serious illnesses like, for example, paranoid schizophrenia are caused due to genetic defects.) but we, with our still primitive knowledge, know that there MAY be a hormonal imbalance involved in causing depression. The hormonal imbalance can be caused by anything really, from experiencing psychological abuse as a child to head injury or something else entirely like immunological or endocrine disorders.

Take obesity for example, it can increase the risk of cardiovascular diseases and diabetes (most commonly diabetes mellitus) but it CONTRIBUTES rather than directly causing the condition, at least most of the times. Same goes for the brain, chemical imbalance can cause for a short interval diseases like clinical depression, dysthymia, etc. however, we do not understand all pathology of the human body itself, let alone completely understand something as sophisticated and evolved as our brain. My point is, if you don't know everything about a car, how can you expect to know everything about the engine? Of course there are some exceptions, as of our current knowledge, but it's a fact we do not know much about pathology and treatment of both, the brain and the body. There are many diseases, infectious agents, treatments and even physiology (study of how the body works) yet to be discovered. This is not just limited to medicine or biology, we don't know many things, including many things about supernovas, pulsars, etc. and stuff that scares me cause I don't understand it.

In short, there are two things you should know.

1) Not every disease, especially brain disease, has a known cause and an effective treatment. Remember Dr.Hawking, the physicist? He had a neurological disorder called amyotrophic lateral sclerosis and he died, despite being one of the most famous scientists and thus one of the most important scientists. Had we known enough about the brain itself, we could have treated Hawking and he his death could have been prevented. He would never have had to be in a wheelchair, if we could somehow cure ALS.

2) It's a theory that brain disorders like depression are caused by chemical imbalance. The truth is, it could be caused due to an injury or an infection as well, the latter is unlikely but possible. In science, nothing is taken for granted. Everything is taken with a grain of salt (the salt is taken from acid base neutralization....)