Adriana, also known as "Ade", was a mobster's dream girl, having grown up around wiseguys all her life by virtue of being the niece of Jackie and Richie Aprile. Growing up she saw and heard plenty, and wasn't at all repulsed by the Mafia lifestyle. Adriana was initially portrayed as shallow and materialistic, interested in the things that Christopher's money could buy: expensive cars, shoes, jewelry, drugs, designer clothing and furs. However, as the couple became closer, she always seemed to have Christopher's best interests (as well as hers) in mind. She was very ambitious and wanted to have a business of her own. When Christopher took a failing nightclub in Long Branch to settle a gambling debt, he gave it to Adriana to manage (although there may have been signs he lacked confidence in Adriana's ability as a business owner, as evidenced when Christopher kept the former owner in his employ as her assistant manager, telling her that his years of his experience were needed). She named her club Crazy Horse, and it later proved relatively successful as a venue, although it would indirectly lead to her doom much later in the series.
The FBI long targeted Adriana as a potential weakness in the family's organization. Upon the death of Sal "Big Pussy" Bonpensiero, the FBI looked to Adriana as a close relation to a rising star in the crime family and sent Deborah Ciccerone to befriend her. Ciccerone succeeded at befriending Adriana, but they had to cut the mission short earlier than planned after Christopher made a pass at Ciccerone, causing Adriana to defend her boyfriend and accuse "Danielle" of trying to make a move. Nonetheless, the FBI learned of Christopher's heroin problem, which they knew would enrage Tony Soprano, and turned Adriana into an informant by threatening her with jail time for cocaine distribution at the nightclub she managed. (Ironically, when Christopher recently acquired the club and was not yet into heroin, he had gotten rid of all drug pushers, well aware of the DEA's interest in nightclubs).
Out of loyalty to Christopher, Adriana avoided giving up any serious information on the family and did her best to avoid the Soprano family house in order to have nothing to give back to the feds. Her deception caught up with her after the FBI learned of her involvement in covering up a murder at her club and threatened to press charges of being an accessory to murder against her unless she offered full cooperation, to include wearing a wire. She chose to reveal the truth to Christopher, hoping they could run away together and start new lives. Christopher was enraged, beating and almost strangling her to death, before breaking down crying. His loyalty to his crime family turned out to be greater than his love for her, as he revealed Adriana's status as an informant to Tony Soprano. Tony had Silvio Dante, under the pretense that he was taking her to Christopher (who Adriana was told had attempted suicide), execute her that very day. As with Richie Aprile, Big Pussy Bonpensiero, and Ralph Cifaretto, not everyone is exactly sure what happened to her. Carmela, along with many others, believe Adriana moved away after breaking up with Christopher.
There was initial speculation Adriana may not have been killed — the primary reasoning for this was her death was not seen, which was unusual in the course of the series; the camera tilted upward, away from Silvio and the crawling Adriana, before two gunshots are heard. De Matteo was also under contract to appear in the sixth season. However, in her audio commentary on the fifth season DVD, de Matteo confirmed Adriana is indeed deceased, and the show's frequent use of dream imagery instead provided for her return; she appeared in a dream of Carmela's in the sixth season premiere on March 12, 2006, "Members Only". Also in that episode, Carmela asks Tony about Adriana (he quickly changes the subject).
In the Season 6 episode "The Ride", Carmela runs into Adriana's mother, Liz La Cerva, who looks shabby and unkempt due to depression. Liz tells Carmela that she believes Christopher killed Adriana, and that the FBI came to her with questions about her. When Carmela tells Tony about their conversation, he explains there was no body, and reminds her that if the FBI really thought Christopher had killed her, they would have hauled him in.
While in Paris, Carmela dreams of seeing Adriana in a park, but a policeman tells her Adriana is dead, and asks Carmela to make this clear to her friend. Carmela is intent on finding her, especially after Liz La Cerva lands in the hospital following an attempted suicide. However, Tony and Silvio pull some strings and Carmela is able to continue construction on her spec house, and the distraction keeps her from investigating the matter further.
After Christopher's murder in "Kennedy and Heidi", Carmela showed remorse over thinking he had killed Adriana, stating, "He could never let himself take her life. Why are we so quick to blame? What is the attraction in that?"