In functional romantic relationships, it's psychologically healthy to feel a deep sense of belonging and attachment. However, becoming overly reliant on another person to feel whole, healed and secure is not only harmful to our wellbeing — it can damage relationships over time. 

This behavior is often referred to in mental health circles as codependency. People in codependent relationships develop a strong, unhealthy devotion to their partner, often at the expense of their own needs, because their identity revolves around taking care of and gaining approval from the other person. 

As a Harvard-trained psychologist who frequently works with clients with relationship issues, I have found that healthy relationships of all kinds require trust, vulnerability, and some degree of interdependence, rather than codependence. 

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At its core, interdependence is an understanding that relationships are a collaboration. Hallmarks of interdependence are mutual support, shared decision making, healthy boundaries and honoring each other's individuality.

Here are 9 phrases healthy, thriving and interdependent couples don't say: 

1. 'I don't need anything'

People who are codependent in relationships often try to hide, ignore or deny their own internal experiences, focusing all their energy on being there for the other person.

This self-sacrificing behavior is often part of an unconscious attempt to get a measure of control over a situation. But we all have needs.

The interdependent goal is that the needs, desires, dreams and wants of both partners are honored, supported and appreciated — and no one asks the other to give too much of themselves.

2. 'Everything is fine'

Codependency is ultimately a need to maintain a relationship at all costs because a person's wellbeing and sense of security is based on that relationship.

As such, people in codependent relationships tend to avoid conflict whenever possible. If it emerges, instead of communicating their thoughts, feelings or perspective, they are likely to be passive aggressive or seem detached.

Interdependent couples will share how they feel, what they want, and then will listen to their partner's response. They know that this practice will build a stronger bond, even when they disagree. 

3. 'I can't say "no" to you'

People in codependent relationships often have a hard time saying "no" or setting healthy boundaries because meeting the needs of others is more important than tending to their own. 

Fear of rejection or ridicule leads them to do what others want even when it's inconvenient, difficult, enables bad behavior, or is a violation of their personal values.

People in interdependent relationships, however, understand that they can say "no" and set boundaries without fear of retribution. They can acknowledge what the other person wants in a respectful way, and have the freedom to authentically say "no."  

4. 'My feelings are not that big of a deal'

People in codependent relationships are strongly influenced by feedback from others, so they're likely to be confused or unsure about their true emotions. They may minimize, deny or alter how they really feel in an effort to maintain the relationship.

It's normal for any of us to be unsure of how we feel sometimes. However, people in interdependent relationships strive to understand, process and explore their true emotions internally, and then share them honestly. 

5. 'Are you mad at me?'

It's very hard for most of us to deal with rejection or criticism — it feels good to have others like us. Yet for people who are in codependent relationships, it can feel intolerable to be disliked or unwanted. 

This leads some to become overly focused on their partners' opinions of them, often compromising their authentic selves in the process.

In interdependent relationships, while the goal is to hear your partner 's perspective and respond in a respectful way, there's also a deep understanding that our value is defined internally. We don't need other people to like everything about us to be whole, healed and important. 

6. 'I can't be alone'

People who struggle with codependency tend to be incredibly uncomfortable when they're not in a relationship. 

Being single or without another person to care for doesn't last long because they will seek out another relationship to fill the void when one codependent relationship ends.

To be in a healthy interdependent relationship means that you know that you are a complete person with goals, interests, and an identity — with or without a partner. Interdependent people embrace their solo time, especially when they are in a relationship.

7. 'Never leave me'

People who struggle with codependency have a difficult time trusting others. Fears of abandonment is often front-and-center: They try to be everything to another person, by being overly responsive to their needs in an effort to make them stay.

To be in a healthy interdependent relationship means that you understand you can't control other people. 

While you may fear a relationship will someday end, there's an appreciation for the present and motivation to build a healthy connection, without controlling their partner. 

8. 'I'm not good enough'

Many people in codependent relationships struggle with low self-esteem and an unstable sense of personal value. They can be very critical of themselves and others, often looking externally for self-validation. 

In interdependent relationships, people strive to look within and take responsibility for their own self-worth, while also leaning on loved ones for support when they need help.

9. 'Do you really love me?'

People in codependent relationships often seek reassurance from their partner. This can look like asking whether they love them, seeking compliments, wanting constant contact and generally seeming clingy or needy.

In interdependent relationships, there's a desire to connect with, trust, and bond with a partner. Yet people generally state their needs directly and discuss them in a collaborative and respectful, rather than clingy-seeming, way.

How to create meaningful, interdependent connections

If you feel insecure in your relationship, try saying that directly. Talk about ways to make you and your partner feel loved and appreciated.

The important thing to remember is that people don't become one when they're in a relationship. They remain as two unique individuals with their own needs, wants and perspectives, who actively choose to share a key aspect of their lives.

As important as trust, intimacy and vulnerability are to the success of a couple, so is building your own self-esteem outside of the context of that relationship. 

Ultimately, maintaining our autonomy and remembering that we have the same value — with or without other people — is key to developing authentic, meaningful and healthy connections.

Dr. Cortney S. Warren, PhD, is a board-certified psychologist and author of "Letting Go of Your Ex." She specializes in love addition and breakups, and received her clinical training at Harvard Medical School. She has written almost 50 peer-reviewed journal articles and delivered more than 75 presentations on the psychology of relationships. Follow her on Instagram @DrCortneyWarren.

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