Hearing voices is well studied in psychosis, but unusual perceptions in other senses and in other mental health conditions are often overlooked. This narrative review examined voices and altered perceptual experiences across psychotic, mood, and anxiety disorders. Key findings include: these experiences vary widely within individuals and across diagnoses, often involving multiple senses; existing research focuses mainly on trauma and brain processes as causes; current theories mostly address only voices; new treatments need to be broader; and there are major issues with how these experiences are defined and how they differ across cultures. The review calls for better assessment tools and more consistent research methods, and emphasizes including patients' own perspectives and cultural context.
Visual hallucinations in people with psychosis typically occur daily, last a few minutes, appear directly in the line of sight, and most often involve seeing persons or animals. These hallucinations are difficult to control and usually cause negative emotions. Among participants who also experienced voice-hearing, 46.8% reported tactile hallucinations and 39.0% reported olfactory hallucinations. Those with affective psychosis were more aware of their hallucinations and had less functional impairment than those with nonaffective psychosis. The study describes common themes across these hallucination types and calls for more research on less-studied hallucination modalities.