Chloe is a stubborn, mischievous, and rebellious young woman. She is the archetypal punk-rocker, expressed in both her music taste and style. She loves to get high, drink beer, and can be described as bold and outgoing. She has a big mouth often making snarky comments, acts fearless and loves to take risks, which often gets her in trouble. She can be prone to angry outbursts, and has serious issues with abandonment and trust after her father's death, Max's move to Seattle, and the disappearance of Rachel Amber. Due to all her bad experience over the years, she has become pessimistic and resentful of life, convinced that there wasn't really anyone who actually cared about her or who she could trust in.
She sometimes is very insensitive to other people's feelings, and may act selfish and possessive, always wanting her loved ones' attention for herself and getting jealous and resentful if they don't spare their time for her or don't act her way. She can also be very irrational and irresponsible, which often takes the form of blaming others for situations out of their control and avoiding any responsibility of damage caused by herself (i.e, when she says to Max that if she doesn't blame someone else, it's her fault), which even takes the extent of blaming her dead father for her misery; but she will in some instances eventually acknowledge when she was in the wrong and apologize. Nonetheless, Max is aware of Chloe's flaws but still cherishes her highly and considers her a "good friend who shows up when you need her". Chloe also is a very protective, devoted and faithful companion, though she tends to get too attached and obsessive. She is pretty straightforward with her (romantic) feelings for other people, and also very flirtatious and teasing. Despite her rough outward appearance, Chloe is actually a very insecure and anxious person, and her tough acting may be nothing more than a facade she built up to protect herself from further harm.
Chloe very likely has to deal with depression caused by her experience of loss and abandonment, and it's implied that she suffers from insomnia and even had suicidal thoughts prior to Max's return. It's possible that her line "Rachel saved my life" literally refers to her preventing Chloe from committing suicide.
She appears to show symptoms of a condition called Borderline Personality Disorder, as characterized by her trust and abandonment issues. During a conversation with Max in "Chaos Theory", Chloe is shown having a meltdown and expressing typical fears of someone who has BPD.
Chloe often drinks alcohol and smokes as a form of self-medication. She has had problems with drug addiction in the past, evident from her stepfather's comment about weed being a big deal for her, as well as her large debt with the drug dealer Frank Bowers. Although Chloe was smart enough for Blackwell Academy, which is evident from the alternative timeline Chloe's school report, she abandoned her studies. All these self-destructive character traits of Chloe, including her rebellion against authorities and her family, her drug abuse, her "boy toy phase" and the loss of control about her own life, which becomes apparent in her chaotic lifestyle and her lack of scholastic and occupational ambition as well as her refusal of responsibility, can be linked to her depression, representing Chloe's way to deal with her desperation, to fill her inner void and to ease her pain. Also, her lack of sensitivity can be tied to her experience of loss and abandonment and her consequent depression.
During her time with Max, Chloe's personality seems to grow a lot, since she finds new strength in Max's support and the resurgence of their friendship. Although Chloe may not seem like that on the outside as it is hard for her to show those traits, as their story proceeds, she appears able to show