In search of a therapist for Luke Spencer, Alexis Davis went to a homeless shelter to meet with Dr. Cameron Lewis. Despite an initial mistake in identity, Alexis was able to convince Dr. Lewis to take Luke on as a patient. After trading insults and stories, Dr. Lewis was finally able to get Luke to open up about Laura. When Luke landed in jail again for his latest fiasco, Dr. Lewis persuaded the cops to release Luke into Dr. Lewis' custody. While still under Dr. Lewis' care, Luke discovered a woman who bore a resemblance to a younger Laura, but he couldn't prove her existence. Dr. Lewis believed that Luke fabricated this woman named Summer to help him grieve for Laura, but he humored Luke by "helping" to look for the woman. As each attempt to prove the existence of Summer failed, Luke was almost convinced that he made her up. Dr. Lewis tried to force Luke to admit that he made up Summer but when Luke refused, Dr. Lewis had Luke committed. Luke then made a desperate attempt to pull Summer out of hiding. It worked, and Dr. Lewis finally got to meet her.
Cameron rescued Alexis when she went into premature labor in the park and then later helped persuade the doctors to allow her to stay in the NICU continually with her baby. Concerned over Alexis' obsessive behavior, Cameron tried to get Alexis to let go of her hatred for Alcazar and be realistic about her life. When Alexis insisted on defending Jax, and then Brenda, in the Alcazar murder case, Cameron enlisted Felicia's help in investigating the case. When it appeared that Brenda was going to go down for Alcazar's murder, Jax tried to get Cameron to declare Brenda mentally unstable but Brenda refused. Instead, she wanted Cameron to help hypnotize her to try to remember more about the night in question.
Alexis accidentally told Cameron that Ned wasn't Kristina's biological father. He told her that he abandoned his son years ago and had always wanted to change things, which was why he came to Port Charles. It was soon revealed that Zander Smith was Cameron's son. Zander ran away from home after his older brother Peter was killed while hunting and his father blamed Zander for Pete's death. When Zander realized that Cameron was in town, he remembered what happened between them and started to self-destruct. Cameron and Zander finally met when Cameron was assigned to be Zander's therapist. They had it out over the shooting incident, with Zander trying to defend his actions and Cameron blaming him for them. Gia attempted to get the two to patch things up, but it didn't work although Cameron was quick to defend Zander to Nikolas.
After Cameron discovered that Alexis had been having memory lapses, he followed her for awhile and figured out that she was acting and even dressing up exactly like her dead sister Kristina. When Skye remembered seeing Alexis in Alcazar's hotel room the night of the murder, Cameron tried to stall the investigation in order to help Alexis. Cameron was able to get the personality of "Kristina" to admit that she killed Alcazar. When Alexis realized what happened, she begged Cameron to help her and he agreed. When the cops wanted to arrest her, he was able to convince them to take her to the hospital for treatment. While treating Alexis, Cameron figured out that Alexis was faking her dissociative identity disorder but reluctantly agreed to continue with her plan. Together, they went to great lengths to try to convince the judge that she was insane at the time of the murder. Cameron also helped her to see her daughter despite court-orders to the contrary. When put on the witness stand, Cameron committed perjury and testified that Alexis had DID. The judge ruled that Alexis was not guilty by reason of temporary insanity and ordered her to undergo treatment.
Alexis became determined to "get well" in a short period of time and get her baby back. But Cameron told her she's in denial. Frustrated, Alexis tried to rebuff Cameron's efforts to help her. But he continually reminded her that sessions with him were court-ordered. When Alexis schemed to kidnap Kristina, Cameron arranged to keep Alexis and the baby in hiding for a few days of quality time together. He covered for her when others asked him if she had the baby and he even got arrested. When the baby was finally returned to Ned and the Quartermaines, Cameron blackmailed Edward into letting Alexis see Kristina.
On the anniversary of Peter's death, Cameron revealed that Peter committed suicide and that Zander wasn't responsible for his brother's death. When Zander asked why Cameron never tried to find him and tell him, Cameron told him that he thought Zander would be better off away from Cameron.
A love/hate relationship developed between Cameron and Alexis. They continued to fight over her efforts to regain custody of Kristina. She told him to back off and he got upset with her for not listening to his warnings and advice to be patient. But she continued to ask for his help and he continued to give it. Alexis went so far as to call a hearing to try to convince the judge she's ready to get her baby back. Cameron tried to speak for her, but the judge wouldn't hear it and wondered if Cameron could be an objective therapist for Alexis. The judge then told Alexis that it's up to the judge and not her as to how quickly she would get her baby back. Afterwards, Cameron questioned her ability to have an adult relationship and told her she needed help. She ignored him and launched into her next scheme of impersonating a male butler at the Quartermaine's in order to spend more time with Kristina. When she broke her scheduled appointment date, Cameron dropped her as his patient but promised to continue to help cover for her as much as he could. He also agreed to hide the fact that she's dressing as a butler. Elated, Alexis kissed Cameron while still dressed as the butler. Zander saw it and thought that his dad was gay. When Cameron found this out, he wanted Alexis to drop the act so that he could tell Zander that he wasn't gay but she refused.
Cameron got pulled back into Luke's troubles when Luke wanted him to find out where Nikolas had hidden Laura. When Cameron refused, Luke held a knife to his throat and then collapsed. Cameron warned Lucky against telling his dad where Laura was at. He thought that Luke should be committed so that he could receive the proper treatment. Lucky didn't know what to do but eventually agreed. Luke later escaped and Cameron asked Lucky if he helped him.
In an attempt to help Alexis, Cameron scolded Ned and Skye for pushing Alexis out of Kristina's life. When Skye discovered the true identity of the butler, Cameron thwarted her attempts to uncover that Alexis was also faking her illness. When Alexis was set up and didn't react with another personality as would be expected, Cameron told a gloating Skye that she only helped prove that Alexis was well and ready to regain custody of Kristina. Later Skye overheard Cameron and Alexis discuss how he knew that she was faking her illness. Skye then arranged a dinner party and invited Cameron, the judge in Alexis' case, the D.A., and a respected psychiatrist who specialized in Alexis' "illness." They speculated on whether Alexis could really be "cured" so soon and after suggesting that Cameron hid the fact that Alexis was faking, Alexis revealed that she's really the butler and that she did fake her illness but Cameron didn't know about it. Cameron thanked Alexis for covering for him, but Alexis blamed him for the new restraining order against her. He reminded her how he helped her through all her less-than-brilliant ideas but she still blamed him. When she got arrested for violating the new restraining order and she asked for his help, he refused.
Zander went to see Cameron to thank him for trying to help Alexis although Cameron didn't think he helped her that much since she does whatever she wants despite his warnings and pleas to follow the rules. When Zander told him that he's leaving town since he's not with Emily anymore, Cameron urged Zander to forgive her and get her back. When Alexis came to him and asked him to help her deal with her past actions, Cameron told her that he couldn't give her what she seemed to want. He also berated her for her new plan to ruin Ned's life in order to get Kristina back. But despite all his grumbling, Cameron continued to try to help Alexis gain access to Kristina.
When the judge wanted to remove Kristina from Ned's care and place her in foster care due to the rape allegations against Ned, Cameron pleaded for Kristina's best interests to be thought of first. So the judge gave Kristina to Cameron. Cameron couldn't find a kid-friendly apartment building, so he arranged with Alexis to rent out a room at Alexis' apartment, thereby allowing Alexis to be near her daughter and pleasing the courts at the same time. Cameron also tried to rescue Alexis when she was arrested for masterminding the fraudulent rape charges filed against Ned. But neither Scott nor Ned would listen as Cameron pointed out that Stefan was obviously the true culprit. When Stefan was killed, Cameron convinced Alexis to grieve for the brother she lost whether only recently or long ago. He even attended the funeral with her where he met Helena for the first time. But he couldn't prevent Alexis from being a control-freak once again and aiding Dara in her own defense in court. During Alexis' trial for fraud, Ned shocked them all by dropping the charges against Alexis so that Kristina could live with her mother. Once daughter and mother were reunited, Cameron tried to walk out of Alexis' life. But the pair wound up dating each other.
Cameron was Carly's therapist after she came out of her coma. He reassured her that the flashes of light and headaches she was having would eventually go away. But then she started having erotic visions involving Alcazar. Not satisfied with Cameron's suggestion of talking them out in therapy, Carly begged Cameron to put her in Shadybrook. Against his better judgment, he complied. When Jason found out, he went to get Carly out of there. But she had been injected with a hallucinogen without Cameron's authorization. As Jason went to grab her, Carly stabbed him with the same drug. Cameron prescribed an antidote but Jason disappeared before it could be administered. Carly was rescued by Lorenzo instead as Courtney went to find Jason. When Cameron spotted Faith near Carly's room, he told Jason who then had Faith committed in Carly's place.
When Zander was being framed for shooting a cop, he went on the run from the police. Cameron discovered that Maxie was hiding Zander at the PC Hotel and offered to help. Zander was extremely suspicious of Cameron's intentions at first. But Zander had been shot and needed medical attention. So Cameron extracted the bullet from Zander's leg and implored Alexis to defend his son. Alexis finally relented and they left Zander hiding at the hotel. But a fire broke out in the room Zander was hiding in. Cameron found out from Maxie that Zander was most likely dead since paramedics had found a body burned beyond recognition in the same room. Suffering from guilt and disbelief, Cameron went back into the hotel where he met Skye and Luke on his way up the stairs. Luke tried to talk Cameron into coming downstairs to safety but Cameron wouldn't agree. Lucky found them as well and while they were trying to get Cameron to come with them, part of the ceiling collapsed. Cameron pushed Lucky out of danger's way and got knocked on the head by the falling debris. Before he died, Cameron told Luke to take care of his kids and love them like Cameron hadn't with his sons. Lucky managed to get Cameron's body back downstairs and outside where Alexis saw him. She felt deeply sorry for never thanking him for all his help in her life.