Lindsay Lohan comes to Charlie for therapy and they begin a tumultuous relationship.

Charlie dates his daughter's teacher.

Inflamed by Kate's comment that he's only "nouveau smart", Charlie starts covertly dating a brilliant coffee-shop barista. The only problem is that the woman is turned on by sex where there's a chance of getting caught -- and she's Kate's patient.

Charlie blows up at his sister's baby shower.

Charlie and Kate face off as expert witnesses in the same trial.

Charlie dates Jennifer's business partner and finds out she has sexual anger issues.

Charlie - a baseball player with anger issues turned anger management therapist - decides to return to therapy after a bad run-in with his ex-wife's new boyfriend. The only problem is he just happens to be sleeping with the one therapist he trusts: his best friend, Kate.

Charlie falls for Jen's hot new business partner, Lori - played by Charlie's real-life ex, Denise Richards - only to find she thinks therapy is a scam. In the therapy group, Patrick asks Charlie to counsel the angry ghost of his mother, who he believes is haunting his apartment.

Charlie gets an unexpected visit from his hyper-critical, bullying father. In the therapy group, Charlie attempts to help Lacey with road rage.

Charlie shakes up his relationship with Kate while dealing with the return of Jen's ex-boyfriend.

Charlie's trip with the group is interrupted when he gets some interesting news from Kate. Also, Charlie's house is unwittingly used for a porno shoot.

Charlie's plan backfires when he attempts to remedy his group with sleep-deprivation therapy.

Charlie and his ex, Jennifer, are having an issue with how Charlie still tries to manage her life when Cleo - one of Charlie's patients from his prison anger therapy group - shows up on his doorstep, fresh out on parole. Jennifer decides to get back at Charlie by dating the ex-con.

Charlie wonders if his father is developing Alzheimer's.

Charlie lets his father help him coach a high school baseball team with bad results.

Charlie and Kate try to control their sexual urges as they begin work together on their sex study; Lacey starts a new job as a pharmaceutical rep.

The new "evolved" Charlie has to deal with a ghost from his old carousing, baseball-playing days when a unattractive woman he slept with just to break a batting slump shows up as a new patient in group therapy.

Kate steals a patient from Charlie, fueling the competitive rivalry between the two therapists.

Charlie has to evaluate the depth of his involvement in his patient's lives when he accidentally helps his patient who vicariously enjoys other people's anger hook up with a crazy woman.

After Charlie and Kate have sex, he innocently asks her if she wants to go to a movie. Kate interprets this as a romantic gesture, rushes to fix him up on a date the next day with someone else and the two are forced to exam the nature of their odd relationship. At home, Sam kisses a girl at school and a picture of it ends up on Facebook.

Charlie begins a questionable romantic relationship with an ex-patient.

Charlie tries to help his patient with a placebo pill that supposedly reduces anger.

Charlie's neighborhood is up in arms when they find out he's been having clients with anger issues meeting at his home.

Charlie gets jealous and uses a patient to spy on Kate.

Charlie's ex causes him problems with his group when she becomes one of his patient's life coach.

Martin tells Kate that Charlie and Jennifer are getting back together.

Charlie discovers scandalous information about Jen's new boyfriend, Sean, when he joins his therapy group.

Charlie breaks all the professional rules by starting a friends-with-benefits relationship with a hot woman subject from the sex study. Also, Nolan and Patrick fight over a woman.

Charlie's dad falls in with a bad crowd.

Jennifer moves in with Charlie temporarily and Kate gets jealous.

Charlie takes the group on an equine therapy retreat.

Charlie inadvertently puts two patients together in a romantic relationship.

Charlie takes on Cee Lo Green as a therapy patient.

Martin has Charlie's daughter baptized behind Charlie's back.

Charlie begins seeing a new female therapist who used unorthodox therapy methods; Patrick tricks Ed into thinking he won the lottery.