Abstract
Objective: Apathy is defined as diminished motivation and reduced goal-directed behavior accompanied by decreased emotional responsiveness. Besides being a symptom of some neurological conditions and psychiatric disorders, apathy is also a known to be an adverse effect of antidepressants. Although attention to antidepressant-induced apathy has been increasing in recent years, studies about apathy are still very limited and generally presented as case reports. Despite being an important cognitive side effect of antidepressants it is not well recognized and may be misinterpreted as a residual symptom of the psychiatric disorder by clinicians. In this study, we aimed to analyze apathy levels of patients with anxiety disorders (AD) and major depressive disorder (MDD) before and after antidepressant treatment, with a prospective design.

Methods: Our study included 20 MDD and 20 AD patients admitted to Mersin University Research and Training Hospital, Outpatient Clinic of Psychiatry, who have not taken any antidepressant medication for at least last one month. Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Rating Scale (HAM-A) and Apathy Evaluation Scale (AES) were administered before antidepressant treatment and on the 6th week of the treatment. Correlations and relationships between scale scores were analyzed.

Results: Thirty-five (87,5%) of the 40 patients were taking Selective Serotonin Reuptake inhibitors (SSRIs), while 5 (12,5%) were taking Serotonin-Noradrenalin Reuptake Inhibitors (SNRIs). In the whole group of patients, AES scores increased from a mean of 20,5 at baseline to 25 after antidepressant treatment (p<0,05). The increase in AES scores were significant only in patients taking SSRIs (p<0.001). Symptoms of depression and anxiety were improved in both patient groups. The mean HAM-D scores before and after treatment were 17,8 and 8,2 in MDD patients, respectively (p<0,05). The mean HAM-A score was 18,6 in AD patients before treatment, which decreased to a mean of 9,9 points after treatment (p<0,05).

Conclusion: Despite the reduction in depression and anxiety scores, six weeks of treatmet with SSRIs was associated with the development of apathy in our study group, consisting of patients with MDD or AD. Clinicians should bear in mind that apathy is likely to occur within weeks of SSRI treatment and screen for it during the course of treatment.