Paranoia is a thought process that can result in people experiencing irrational mistrust and suspicion of others. This pattern of delusional thinking may involve feelings of persecution, making a person think they are in a constant state of danger.

While occasional paranoid thoughts are common, if a person experiences them for a prolonged period, it may be a symptom of a mental health condition.

In this article, we define paranoia and discuss its symptoms, causes, and related conditions.

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Paranoia refers to irrational and persistent thoughts and feelings that cause a person to believe that others are trying to harm, deceive, or exploit them. This may involve people feeling that others are watching, listening to, or following them, despite there being little or no evidence to suggest this.

This unfounded mistrust can make it difficult for people with paranoia to function socially or form close relationships.

Some people may refer to paranoid thoughts as delusions. This is when irrational thoughts and false beliefs become so fixed that not even contrary evidence can convince a person that what they think is not true.

While mild paranoid thoughts are relatively common, experiencing long-term paranoia may indicate a mental health condition. But it is important to note that paranoia does not necessarily suggest a mental health condition.

Symptoms of paranoia can vary, but may include:

  • difficulty trusting others
  • not confiding in others
  • finding relationships difficult
  • being overly suspicious of others
  • considering the world to be a place of constant threat
  • constant feelings of persecution
  • always being on the defensive
  • being hostile, aggressive, or argumentative
  • not coping well with criticism
  • taking offensive and assigning harmful meaning to comments from other people
  • not compromising
  • difficulty forgiving others
  • assuming other people frequently speak ill of them
  • belief in unfounded conspiracy theories

Scientists are still unsure of the exact cause of paranoia, and research is still ongoing. Evidence suggests that a combination of different factors likely play a role. Potential causes may include:

  • Genetics: Having certain genes may affect how likely a person is to develop paranoia. For example, a 2018 article highlights a genetic variation, known as SNP rs850807, as being strongly associated with paranoia.
  • Brain chemistry: Neurotransmitters are chemical messengers that play a key role in brain function and affect thoughts and feelings. For example, a 2018 article suggests the role of dopamine in paranoid ideation.
  • Trauma: Past trauma may distort a person’s thoughts and feelings. For example, a 2017 study notes that childhood trauma is significantly associated with paranoid beliefs and a 2019 study adds that it increases the risk for psychosis.
  • Stress: Evidence suggests that paranoia may be more common in people who have experienced severe or ongoing stress. For example, a 2016 study indicates that stress can result in paranoia, and stress management strategies may help reduce it.

While paranoia is a symptom that can be part of a number of conditions, many people typically associate paranoia with:

  • Paranoid personality disorder: This is a cluster A personality disorder, meaning people display behaviors that others may find unusual. It typically involves suspiciousness of others and interpretation their actions as threatening or demeaning.
  • Delusional disorder: This is a mental illness that causes people to have false beliefs, or delusional thoughts, for a prolonged period despite evidence to the contrary. The thoughts are not necessarily unrealistic, but may not be realistic.
  • Schizophrenia: This is a serious mental health condition that can affect a person’s perception and may involve delusional thinking, such as paranoid thoughts. In the past, experts considered paranoid schizophrenia to be a distinct type of the disorder, but now classify paranoia as a symptom.

It can be difficult to diagnose paranoia, as it is not only a symptom of many conditions, but people experiencing paranoia may try to avoid doctors, hospitals, and other medical settings and may not recognize that they have paranoid thoughts.

Typically, a diagnosis will involve a doctor or mental health professional asking questions about a person’s medical history, performing a physical examination, and assessing symptoms.

A doctor may then require a person to complete psychological tests, blood tests, and scans. This can help a doctor to rule out other possible causes for the symptoms.

If paranoid thoughts are causing distress or are a symptom of a mental health condition, the following treatments may be beneficial:

  • Talking therapies: These types of therapy may help a person to understand their experiences and develop coping strategies to manage paranoid thoughts.
  • Art and creative therapies: These encourage people to channel and express their thoughts and feelings. This may be beneficial if people have difficulty talking about their experiences.
  • Medications: If a person receives a diagnosis of a condition such as schizophrenia, a doctor may suggest antipsychotic medications. These can help reduce paranoid thoughts and allow a person to think clearly and logically. Antipsychotic medications can also help people who do not have schizophrenia but who do experience distressing paranoid thoughts.

Evidence suggests that potential complications of paranoia may involve:

  • Safety behaviors: This refers to behaviors that people may do to make themselves feel safe. This may cause people to avoid certain situations, act aggressively toward others, and push people away.
  • Isolation: Not only may people with paranoid thoughts avoid others, but they may also feel as if no one understands them and find it difficult if others do not agree with their thoughts.
  • Worry and sadness: Paranoid thoughts may also cause people to experience anxiety and low mood due to how they believe their thoughts may affect their life.
  • Stigma: Due to misunderstandings about paranoia and how people with paranoia may act, they may be subject to discrimination by others.

If a person suspects they may be experiencing paranoid thoughts, they may wish to seek help. Initially, it may be beneficial to keep a diary and question their paranoid thinking.

People may also want to confide in someone they trust, try to manage their stress, and try other healthy behaviors, such as a healthful diet, regular exercise, and getting sufficient sleep.

If paranoia begins to disrupt daily life, a person should consider speaking with a doctor or mental health professional. While this idea may seem daunting, a person should realize that medical professionals will not intend to harm them, and are instead there to provide them with support, manage symptoms, and reduce distress.

Paranoia refers to an irrational thought process that causes people to exhibit an extreme mistrust or suspiciousness of others. While research is unclear, evidence suggests that genetics, brain chemistry, trauma, and stress likely play a role.

It can be difficult to diagnose, and people may be hesitant to seek help due to their doubts about other people. Certain therapies and medications may help to manage and reduce paranoid thoughts.