it could be, I know some people who when they are in their mania phase they talk in a higher toned voice then normal due to excitement, stress,... I know some one who talked like a child when ever t hey were experiencing a psychotic episode and hallucinating, their problem was feeling afraid caused their vocal cords to tighten up, so it caused them to have a higher pitched voice.

I also know someone who talked like a child because their vocal cords and voice box wasnt getting used (refused to talk for a long time) due to inactivity her vocal cords stopped working correctly. her doctor referred her for physical therapy because of her yrs as a selective mute she had to learn how to talk all over again, she took voice lessens, singing lessons, now she talks just fine..

I used to be confused for a child. my problem was I had these growths on my vocal cords. after surgery and healing my voice was a bit deeper. now I sound like an adult woman..

I have also sounded like a child when I would become an alternate personality. (DID)

there are lots of reasons why a person's voice sounds like a child, sometimes its genetic, sometimes its a mental problem, sometimes its an emotional (having to do with fear, excitement, stress...) problem and sometimes its because of physical health problems..

your treatment provider can help you discover why you sound like a child and how to fix what ever is causing it. mine were a great help to me.