Insanity, often referred to as madness, is a term used to describe severe mental illness that impairs a person's ability to think clearly, make decisions, or relate to others. It can manifest in various forms, including schizophrenia, bipolar disorder, and severe depression. Symptoms may include hallucinations, delusions, and extreme mood swings, which can significantly affect daily functioning. The legal definition of insanity varies by jurisdiction but generally refers to a state where an individual cannot understand the nature of their actions or distinguish right from wrong. This concept is often discussed in relation to criminal law, where a defendant may be deemed not responsible for their actions due to their mental state at the time of the offense.