Impulsive behaviours (impulse control deficit) and compulsive behaviours (over control) have been considered at the core of different disorders, but patients often present with mixed features of impulsive and compulsive behaviours (i.e. patients with OCD and borderline personality disorder). Therefore, a clinical spectrum from impulsivity to compulsivity could exist, in which obsessive compulsive disorder (OCD) and impulsive personality disorders (borderline personality disorder, antisocial personality disorder…) would be the endpoints.

Regarding treatment, SSRI have demonstrated high efficacy in the treatment of both impulsive and obsessive-compulsive symptoms. On the other hand, topiramate has been described as an effective agent in treating impulsive behavior.

The aim of this study is to test the hypothesis that coadjuvant treatment with SSRI and topiramate would improve the outcome of patients with comorbid OCD and impulsive behaviour disorders.

We will describe two clinical cases admitted to our Psychiatric Hospitalization Unit. Case 1 is a 39 years old female diagnosed with OCD, borderline personality disorder and alcohol dependence and case 2 is a 38 years old male with OCD, mixed personality disorder and cocaine abuse.

Treatment with topiramate (range dosage: 250-400 mg/daily) as well as SSRI (paroxetine 40 mg/daily- case 1; sertraline 200 mg/daily-case 2) improved affective instability and impulsive symptoms in both patients. Topiramate was well tolerated without important side effects.

Topiramate could be an interesting alternative in the coadjuvant treatment of OCD with impulsive features.