Who Is Katherine Cullen, the Therapist Behind Psychology Today’s Exercise Addiction Blog?

Katherine (Schreiber) Cullen, MFA, LCSW, is a psychotherapist and writer based in Knoxville, Tennessee, who contributes a Psychology Today blog titled "The Truth About Exercise Addiction: Understanding the Dark Side of Thinspiration," according to her contributor page on the publication.

Cullen is a licensed clinical social worker who also holds a Master of Fine Arts degree. Before her current work as a contributor, she served as an editor at Psychology Today, per the same source.

What she writes about

Her recent posts span clinical and relationship topics. They include a look at five grounding techniques therapists use to promote calm and emotion regulation, a piece on breaking negative rumination through increased cognitive flexibility, and an article debunking what she describes as four common myths about attachment styles.

Other posts address relationship dynamics directly: strategies for reducing volatile arguments with a partner, why people struggle to leave relationships they logically know are harmful, and how to cope when staying in an unhappy marriage. She has also written on the connection between perfectionism and narcissism, arguing that narcissism can, in some cases, explain the relentlessly high expectations certain people hold for others and themselves.

Her topic range extends beyond the clinical. One post examines the widespread appeal of footballer Erling Haaland during the World Cup, framing the question through the lens of psychology.

Where her work has appeared

Beyond Psychology Today, Cullen's writing has been featured by Time, Cosmopolitan, Shape, Weight Watchers Magazine, Rehabs.com, mindbodygreen.com, PsychCentral.com, and Greatist.com, according to her contributor bio. She has appeared on ABC Nightline, NY1 News, and CBS.

Cullen is the author of "The Truth About Exercise Addiction: Understanding the Dark Side of Thinspiration," a book that shares its title and subject with her ongoing blog. She lists InteGreatSelf among her professional resources and accepts media and public speaking requests through Psychology Today's contact system.

Why the focus on exercise addiction matters

Exercise addiction sits at an uneasy intersection of behaviors that are usually praised. Cullen's work centers on the point where physical activity stops being healthy and becomes compulsive, a framing captured in her use of the term "thinspiration." That angle distinguishes her from wellness writing that treats exercise strictly as a positive, and it aligns with her broader interest in eating disorders and the mental-health tradeoffs of self-improvement culture.

For readers seeking her work, her contributor profile links to social channels and her own practice under the name Katherine Cullen, LCSW.