That is an excellent question and one that you should discuss with this person and urge them to seek medical attention and perhaps even legal aid if this is abuse. Unfortunately, there is very little information provided and so it is difficult to know the person's age, gender or why there is a concern for abuse but instead, a general overview of these symptoms will be discussed below. There are quite a few reasons that someone may speak with an indifferent tone and have mood changes and this could be due to psychological disturbances such as depression
or could be related to bipolar disorder
, and depending on the cause there may be a genetic predisposition, or it could be due to social issues such as abuse as you have mentioned previously. In cases like this, you may consider discussing your concerns with this person, and recommending they see a medical professional, or if this is a child and there is a concern for abuse, you should report this to the police as this can be a serious issue that should be dealt with as soon as possible. Nevertheless, this is a serious issue and should be dealt with by a medical professional and perhaps the police.