Abstract: The present invention relates to the use of a neurotoxin, especially botulinum toxin, for use as a medicament in the treatment of a personality disorder and/or a habit and impulse disorder and/or a conduct disorder, as well as to a method for the treatment of a personality disorder and/or of a habit and impulse disorder and/or of a behavioural and emotional disorder with onset usually occurring in childhood and adolescence by administration of the neurotoxin to a patient diagnosed with this disorder. Preferably, the neurotoxin is for use as a medicament in the treatment of an emotionally unstable personality disorder and/or of another personality disorder and/or of a habit and impulse control and/or behavioural and emotional disorders with onset usually occurring in childhood and adolescence, in which the disorder is preferably characterised by emotional instability and impulsivity.