- Michael: "Do you believe in evil?"
- Isiah: "No. No I don't. I'm a man of science. Evil is a construct made by people who wish to indulge childish fantasies, or... by people who wish to judge others."
- ― Isiah to Michael
On his official website, Dr. Friedlander is said to be a psychotherapist, media personality, secular Buddhist, and keen model boat enthusiast. Isiah received a Bachelor's Degree in marketing from the University of San Andreas, Los Santos in 1984 and a Doctorate Degree in Psychology in 1986 from an unknown defunct learning institution. He has also travelled in Asia frequently.
Isiah has been widely praised for exposing the culture of narcissism in the ganglands of 1980s San Andreas and also criticised for its overuse of hyphens. He is a leading authority in the field of Sociopathic Personality Disorder and has treated both celebrities and criminals. Isiah has become one of the most respected and in-demand therapists in Los Santos as of 2013.
Events of GTA V
Dr. Friedlander is portrayed as an over-the-top version of a "Hollywood" psychotherapist. He's overpriced (as seen in an email where he raises his rates a reasonable 75%) and seems not to actually care about his patients. In cutscenes he's seen looking at his watch waiting for the session time to expire. He is also not concerned much about Michael's behavior as the latter confesses that he is able to kill without remorse and may have killed someone on the way to Isiah's home. However, he is sort of helpful at some points.
Dr. Friedlander also appears in the mission Reuniting the Family in which he listens to Amanda and Michael argue about their relationship but makes no effort to intervene in any way.
Later in the game (in an optional visit), he tells Michael that he is leaving Los Santos and has gotten his own TV show. He then informs Michael that he needs to find a new therapist and implies that he's going to be using Michael's case in his show. Angry, Michael chases after Friedlander. Michael then has the choice to kill him or let him go.
If killed, more than $2,000 can be looted from his corpse and an internet article confirms his death. The internet article, posted in the news reel from Los Santos Meteor, reveals that Friedlander actually made public the sessions of Michael in a published bestseller, nicknaming him Marky De Santos and branding him as an "idiotic, if terrifying and amusingly deluded sociopath".
If spared, the news about his death will still appear. However, after some time, Friedlander will send an e-mail to Michael, confirming that he is alive. In the e-mail, Friedlander explains how sorry he is about what he did to Michael, but how he can now help more people with his new radio program and TV show. He also says that he values the time spent with Michael and that they should both forget what happened between them and move forward. Michael has the option of replying to the e-mail; if so, he states that if he were to meet Friedlander again, he would kill him.
- Franklin and Lamar
- Negativity (Voice)
- Fucked Up (Voice)
- Reuniting the Family
- Abandonment Issues (Can be killed)
- His nickname in high school was "pube head" due to his fuzzy hair.
- When playing as Michael you can hear his commentary on the situation based on in-game events. When asking about Michael's behavior, you can hear a variety of scripted lines depending on how often you've caused mayhem as him, as well as how often you've engaged in adultery as him. You also have the option to agree or disagree with his evaluation of Michael's character.
- An after credits scene shows his Psychiatric Evaluation which notes the player's behavior. This includes, but isn't limited to making the way you make friends, laziness, addiction to chaos, whether he thinks you justify your despicable actions, how often you partake in hobbies like Yoga, and how you handle women.
- Even if Michael has hired prostitutes he will still state that he has had no sexual problems when choosing to agree with the evaluation, suggesting that it's based on whether or not the player courts strippers with Michael.
- If you access the Affordable Healthcare section of the Grand Theft Auto V website and open the photo of him and his name in green in a new tab, you can see that Rockstar Games have labelled him "World Champ" in the URL.
- The year in which he attained his marketing degree may be a referrence to Grand Theft Auto: Vice City Stories, which is set in 1984. His next degree - in psychology - may also refer to Grand Theft Auto: Vice City, set in 1986.