There are many sufferers who can trace their depression back to childhood injuries (both psychological and physical) which may have caused brain damage. Of course, there are some patients who had physical problems to start with who became even more vulnerable to the illness due to personality and outside pressures.
也有許多患者在探討病因時，可以追溯到童年重大的創傷（包括心理和生理），可能造成腦部受損。當然，有些病人是兩者合併的，他們本來就有體質的問題，加上性格和壓力上的影響，就容易發病。