Study elaborates relationship between obesity and MDD-R, long-term use of ADs

This study demonstrates that patients using antidepressants (Ads) continuously, mostly serotonin-selective reuptake inhibitors (SSRIs), show significantly more (abdominal) overweight and obesity than those using them intermittently or not at all. Compared with SSRIs, other types of ADs used (e.g. tricyclic ADs) did not have a significant impact on the anthropometric measures.

In a study published in the last 2010 issue of Psychotherapy and Psychosomatics, a group of researchers of the University of Amsterdam presents new findings on the relationship between weight and recurrent depression.

The literature on the relation between obesity and the recurrent type of major depressive disorder (MDD-R; having had at least 2 major depressive episodes) is limited and equivocal. Most studies on depression and obesity did not distinguish between single and recurrent episodes. However, this distinction may be important because depression is increasingly considered a chronic recurrent disorder with various levels of interepisodic functioning, and evidence is growing that the recurrent type is a distinct one.

Most studies on the relation between depression and obesity did not control for antidepressant (AD) medication use, although a substantial part (20-60%) of the recurrently depressed patients use ADs for lengthy periods of time. This study elaborates on their findings by focussing on the relation between obesity and MDD-R and the association between long-term use of ADs and obesity. To be eligible for this study, ppatients had to meet the following criteria: (a) at least 2 major depressive episodes in the past 5 years (DSM IV), (b) current remission status, according to DSM-IV criteria, for longer than 10 weeks and no longer than 2 years before, and (c) Hamilton Rating Scale for Depression of <10. At 2 years, follow-up assessment anthropomorphic parameters were collected of 134 subjects.

To assess relapse/recurrence, the Structured Clinical Interview for DSM-IV (SCID-I) was used. Regarding the use of ADs, two groups were distinguished: those who used Ads throughout the entire 2-year study period (n = 46) and those who did not use ADs continuously, but intermittently (n = 49) or not at all (n = 39). Differences between these groups in BMI, waist circumference and waist-to-hip ratio were tested stratified by gender. Overweight and obesity occurred more often in patients with recurrent depression than in the reference group, although statistical significance was reached in women only (74% of this sample). Within the MDD-R patient group, serotonin-selective reuptake inhibitors (SSRIs) were the most commonly used type of AD among the continuous AD users. Compared with SSRIs, other types of ADs used (e.g. tricyclic ADs) did not have a significant impact on the anthropometric measures.

The mean AD equivalent correlated positively with both waist circumference (p = 0.006) and waist-to-hip ratio (p = 0.004), but not with BMI. In addition, mean waist circumference and waist-to-hip ratio scores were consistently higher amongst the continuous AD users compared to intermittent and no AD users. Patients using ADs continuously, mostly SSRIs, show significantly more (abdominal) overweight and obesity than those using them intermittently or not at all. Compared with SSRIs, other types of ADs used (e.g. tricyclic ADs) did not have a significant impact on the anthropometric measures. The Authors did find, however, a small association between AD equivalent dosage and waist circumference and waist-to-hip ratio.

In general, a better understanding of the relationship between obesity and depression, i.e. understanding the beneficial and adverse effect of psychotropics on appetite, eating behaviour, body weight and metabolism should improve our ability to prevent and treat both obesity and depression. Thereby, ideally persontailored interventions can be developed, including effective nonpharmaceutical preventive strategies for recurrent depression  and extra physical activities with - as added benefit - protection against AD-induced weight gain.