Pathological gambling (PG) is currently included among Addictive Disorders (DSM-5). However, its phenomenology resembles features of Obsessive Compulsive Disorder. Several models of addiction conceptualize a progression from impulsivity to compulsivity transitioning from initial positive reinforcement motivations to later negative reinforcement and less pleasurable and automaticity mechanisms. Clinical presentation A 34-year-old male, since diagnosed with PG in 2013 and prescribed a group rehabilitation therapy, presented in 2015 complaining of intrusive thoughts and depression symptoms. During the psychiatric examination emerged: low mental concentration; dysphoria; hyporexia; irritability; insomnia; persistent ideas and excessive preoccupations to be betrayed by his girlfriend; and behaviours of hyper control on her life. He has been evaluated using MMPI-2 (obsessivity Tscore 70, depression Tscore 67) and BIS-11 (high score of non-planning impulsiveness). Treatment It appeared there was a shift from ego-syntonic novelty driven/impulsive behaviours focused primarily on gambling to ego-dystonic habit driven/compulsive behaviours focused on her girlfriend. He started an individual psychodynamic psychotherapy centred on dysfunctional beliefs and behavioural strategies for treating the compulsive features. As thought content was the most relevant aspect, he was prescribed olanzapine, not a SSRI (normally indicated for OCD), up to 10 mg/die. After a month obsessions and compulsions reduced, and he seemed to reach a good level of personal functioning, despite a rigid anankastic personality trait. Conclusions As the management of compulsive behaviours is complex, physician should better assess and recognize psychological personality aspect, collecting patients’ complete history, also testing them psychometrically, and paying more attention to an eventual treatment (both psychological and pharmacological).