**6. Psychological side effects of anticonvulsant medication**

Like people with other chronic diseases, patients with epilepsy suffer significantly more often from psychological comorbidities such as depression or anxiety than healthy people. Treatment-refractory epilepsy and epilepsy with a seizure origin in temporal structures are affected with particular frequency [23]. Psychological complaints represent a significant impairment of the quality of life for those affected and require both precise diagnostics and consistent therapy. Treatment with mood-stabilizing, antidepressant drugs and accompanying psychological psychotherapy should therefore be considered for these patients. Concerns about possible proconvulsive effects of antidepressants are usually unfounded (with a single exception: amitriptyline) and should not prevent therapy.

However, before starting antidepressant therapy, it must be clarified whether the psychological complaints of the patient are possibly an undesirable interference of the anticonvulsant medication: Substances like topiramate, zonisamide, levetiracetam, and perampanel can have a negative impact on mood [13, 24]. Depressive and psychotic symptoms as well as increased aggressiveness were observed with topiramate. With levetiracetam, depressive symptoms can occur in individual cases as an undesirable drug interference effect as well. Much more common with this substance, however, are increased irritability and aggressiveness, which can unsettle both patients and relatives and in some cases lead to serious problems in the social environment. A dose reduction or a switch to another medication is advisable in both cases. For example, brivaracetam, which has been available since the beginning of 2016, promises to have a lower impact on psychological well-being with a similar mechanism of treatment [25–27].

With regard to psychological comorbidities, lamotrigine should be emphasized as an anticonvulsant with a probably additional antidepressant effect. Lamotrigine is therefore particularly recommended for patients with depression. However, lamotrigine can lead to unwanted sleep disorders, especially in the initial phase. This can be countered either by reducing the dose and then increasing it more slowly or by redistributing the individual doses during the day (higher dose in the morning, lower dose in the evening). In addition to lamotrigine, pregabalin also has a beneficial effect on psychological comorbidities, especially anxiety and sleep disorders. Topiramate, which is used in lower doses also for migraine prophylaxis and addiction therapy [28], can be used in patients with additional migraines - taking into account the above-mentioned factors relating to cognitive performance.
