Catelynn Lowell has struggled with mental illness since she started filming "Teen Mom OG." Catelynn admitted on "16 & Pregnant" that she had gone through some troubles in her childhood and she admitted that her family situation was not ideal for a baby. Lowell revealed that it was best for her to give up her daughter, Carly, for adoption when she arrived. While her boyfriend, Tyler Baltierra, really wanted to keep their daughter, the two eventually decided to give her up to the adoptive parents. They chose to have an open adoption, so they could see their daughter as she grew up.

But giving away their daughter may have caused some friction and perhaps even some depression.

According to a new Instagram post, Catelynn Lowell revealed that it was time for them to meet up with Carly and they were bringing their second daughter, Nova. These two girls are biological sisters, as they share the same parents. But Carly is being raised by her adoptive parents. While Catelynn has kept her feelings somewhat to herself, fans now believe that giving up her daughter for adoption may have led to her depression.

Postpartum depression

One could argue that Catelynn Lowell struggles from postpartum depression, even though she gave up Carly. She had to go home without the baby she had been carrying for nine months, and some fans believe that this caused her to feel depressed.

She also struggled with depression after Nova was born, but she addressed it. However, some fans believe that her depression may stem all the way back to when she chose to give up her first daughter.

"I think this is why Catelynn suffers from depression I bet she regrets so much have given up Carly for adoption," one of Catelynn Lowell's followers wrote on her Instagram post.

Life after adoption

Of course, life after an adoption isn't easy, and this could be why MTV decided to feature Catelynn Lowell on "Teen Mom OG" even though she wasn't parenting Carly. She had given up her daughter, but the network may want to show viewers what life is like after a teenager decides to give up a baby for adoption.

Adoption is a theme that has surfaced in several stories on the show and on "16 & Pregnant."

Even now, Briana DeJesus on "Teen Mom 2" considered adoption for her second baby as she didn't want to be a single mother for her second baby. Her boyfriend had abandoned her during the pregnancy with Nova, and she didn't want to do a repeat.

What do you think about fans' theory that Catelynn Lowell's depression steps from the adoption?