The frequency of severe adverse drug reactions (ADR) of psychotropic drugs in relation to age is investigated and especially the incidence in hospitalized patients aged up to 60 years is compared with patients aged above 60 years.

The data - prescription rates of psychotropic drugs, reports of severe ADR - are taken from psychiatric hospitals in Switzerland between 2001 to 2010 and stem from the drug surveillance program AMSP.

699 patients exhibited severe ADR: 517 out of 28282 patients up to 60 years (1.8%); 182 out of 11446 elderly patients (1.6%, ns). Linear regression analyses show a significantly decreasing relationship between the incidence of ADR and patients’ age in general and in particular for weight gain, EPMS symptoms, increased liver enzymes and galactorrhoea. Delirium increases with age. A significantly decreasing relationship was observed for age and the dosages of olanzapine, quetiapine, risperidone, valproic acid and lamotrigine. Comparing age groups, lower frequency of ADR in general was found for antipsychotic drugs and anticonvulsants, in particular also for valproic acid in the elderly. Weight gain was found to be lower in the eldery for antipsychotic drugs, in particular also for olanzapine. For the group of mood stabilizing anticonvulsants (carbamazepine, lamotrigine and valproic acid) the elderly exhibited a lower incidence of reported allergic skin reactions.

The results suggest that in hospitalized patients the incidence of common severe adverse effects such as weight gain and EPMS symptoms as a consequence to psychotropic medication decreases with age.