Schizophrenia is a mental disorder, in which the sufferer has difficultly distinguishing between reality and fantasy. The disorder plays a large role in Paranoiac, as the main protagonist, Miki Takamura, shows many symptoms of it and is diagnosed with schizophrenia in the Good Ending. It is possible that Miki's aunt, Saeki, also had schizophrenia.
There are several different symptoms of schizophrenia, and not every person with the condition will experience it in the same way. These symptoms can include:
- Hearing voices
- Paranoia (feeling someone is out to get to you, that no one likes you, that you're in constant danger etc.)
- Seeing things that aren't really there/hallucinating
- Memory loss/forgetfulness
- Believing things have been said or done, when they actually haven't
- Having difficulty distinguishing between reality and fantasy
- Believing someone or something is trying to harm you, and taking drastic measures to prevent it
Miki Takamura has symptoms of schizophrenia, such as feelings of anxiety or fear, paranoia and hearing things. It is also possible that the Monster that stalks her throughout the game is actually a vivid hallucination, which would definitely be a sign of schizophrenia.
Saeki also has symptoms of schizophrenia, such as believing everyone hates her, believing everyone thinks she's a killer, hearing voices telling her to die, hallucinating stuffed animals coming alive and telling her to kill herself and hallucinating her niece telling her to kill herself (which Miki would never have done in real life, as she adored her aunt). Saeki also had feelings of anxiety and paranoia, stating in her online diary that she didn't feel safe unless she locked all of her doors and hid the keys.