New study shows that like attracts like, especially when it comes to mental health

Many books and studies have focused on how we choose partners and fall in love. A new line of research centers on people forming relationships around shared mental health challenges.

A 2025 study revealed that people choose partners based on more factors than just common religious beliefs, political affiliation, core values, and hobbies. There is one factor that has a large-scale effect on relationship satisfaction: navigating a similar mental health diagnosis. Looking at several studies exploring reasons why people choose romantic partners, a psychiatric diagnosis was a strong indicator of a successful match.

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Relationships formed over psychiatric disorders

After analyzing data collected from more than six million couples, researchers assessed the types and numbers of psychiatric disorders that were shared by couples. Using national health insurance data, researchers found that people diagnosed with similar disorders were more likely to marry someone navigating the same issue.

There are many reasons a person may feel attracted to someone and find satisfaction in a relationship. To better understand the study's results, researchers examined the underlying reasons people with similar mental health conditions are more likely to form romantic relationships with one another. A 2025 article by PsyPost explored the idea that "birds of a feather flock together" when examining mental health–based attraction through the lenses of attachment theory, social identity theory, and assortative mating.

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Understanding attachment theory

Attachment theory examines how early bonds form between infants and their primary caregivers. The dynamics of this bond shape what we find attractive in a partner as we age. A 2023 study found that secure attachment is associated with higher well-being and more stable romantic relationships.

In this way, people with certain disorders, such as anxiety and depression, may develop anxious attachment styles. One example offered was that fear or abandonment issues could manifest as an increased need for reassurance, such as sending more frequent texts to a partner. When the other person shares similar mental health challenges, their attachment style is also likely to be anxious. The texts would therefore not be a turnoff, but rather a shared way of navigating the stress of the relationship.

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What is social identity theory?

Social identity theory explains how individuals gain a sense of belonging and self-esteem through their membership in social groups. Relationships that grow from shared experiences draw on those common understandings to build validation and connection. A 2024 article in PositivePsychology.com examined individuals' ability to modify their behavior to conform to group norms. However, when psychiatric needs are similar, there is less difficulty in establishing relatable experiences and shared meaning.

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The facts around assortative mating

Assortative mating is based on the simple premise that people choose partners who are similar to themselves. Traditionally, factors such as religious background, cultural similarities, education, height, and personality are considered. People facing specific psychiatric disorders, such as obsessive-compulsive disorder or bipolar disorder, may feel safer finding partners who share firsthand experience. The recent study suggests that assortative mating is prevalent enough in mental disorders that their transmission can be traced through family histories.

As people follow the drive to find a good partner, connections often grow stronger through shared values and common experiences. Individuals navigating a specific mental disorder may find solace and understanding with a partner who not only empathizes but also lives with the same condition.