TLC 'Long Lost Family' shocker: Family lies give Seanne identity crisis (Exclusive video)

In Sunday's episode of TLC's "Long Lost Family," Seanne must reckon with a shocking discovery — one that her family kept from her for most of her life.

Spoiler: She was adopted as a baby.

"If family can hold a secret that big for that long, then I felt a lack of trust in almost every relationship that I had with everybody else," she says in a new preview clip from the new episode.

Seanne found out about her adoption when she was 25 years old, leading to an identity crisis and an inability to trust anyone close to her. In the clip she says it's taken her down a "dark path" in life.

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She has become determined to find her biological mother and discover the true story about how she came into this world. Her adoptive mother has supplied a few pieces of information about her provenance, but the vague stories and limited details have not proven to be of much help in Seanne's search. It's been nine years and she's had no luck

"I need to find my biological mother," she says.

"Long Lost Family" airs Sunday at 9/8c on TLC.

Read original story TLC 'Long Lost Family' Shocker: Family Lies Give Seanne Identity Crisis (Exclusive Video) At TheWrap