Table 1. Clinical studies on the effects of antidepressants on body weight.

Study	Significance	Sample size/duration	Limitation
Major depression, antidepressant medication and the risk of obesity89	SSRI and venlafaxine were significantly associated with obesity.There was no significant association between TCA or antipsychotic medications with obesity	NHPS sample (1994–2004) n=17 276	Confounded by prescription. Physicians may have specifically selected these medications for use in patients who they believe to be most at risk of weight gain
MetS abnormalities are associated with severity of anxiety and depression and with tricyclic antidepressant use87	Tricyclic antidepressants increased the odds for MetS	n=2981	The main focus of this study is on MetS and different levels of depression
Long-term weight gain in patients treated with open-label olanzapine in combination with fluoxetine for major depressive disorder90	Patients were treated with a combination of olanzapine and fluoxetine (OFC). Increases in fluoxetine dose were predictors of weight gain. Long-term (76 weeks) OFC treatment may lead to a large percentage (56%) of patient meeting the criteria for significant weight gain (>7%)	n=549
Real-world data on SSRI antidepressant side effects79	36% of patients experienced side effects associated with SSRI. Forty-nine patients had weight gain	n=700 Patients
A naturalistic long-term comparison study of selective serotonin reuptake inhibitors in the treatment of panic disorder91	Weight gain Paroxetine: 8.2±5.4 kg Fluoxetine: 5.2±4.4 kg Citalopram: 6.9±5.7 kg Fluvoxamine: 6.3±4.2 kg	Duration: 1 year n=200
Changes in weight during a 1-year trial of fluoxetine92	12-Week treatment: –0.35 kg 50-Week treatment: +3 kg	Duration: 50 weeks n=395
Changes in body weight during treatment with the new antidepressant Nefazodone, three SSRIs Fluoxetine, Setraline, Paroxetine, and the tricyclic Imipramine93	Significant weight loss or gain was, respectively, defined as ⩽7 and ⩾7% change in body weight from baseline. Study 1 Acute phase trial SSRI: 4.3% of treated patients lost weight at any point Nefazodone: 1.7% of treated patients lost weight at any point Long-term phase trial SSRI: 17.9% of treated patients had weight gain Nefazodone: 8.3% of treated patients had weight gain Study 2 Acute phase trial Imipramine: 4.9% of treated patients had weight gain Nefazodone: 0.9% of treated had weight gain Long-term phase trial Imipramine: 24.5% of treated patients had weight gain Nefazodone: 9.5% of treated patients had weight gain	Study 1 Acute phase trial: 6–8 weeks n=1036 Long-term phase trial: 16–46 weeks n=608 Study 2 Acute phase trial: 6–8 weeks n=1036 Long-term phase trial: 16–46 weeks n=135
TCA-induced weight gain76	TCA antidepressants Amitriptyline, nortriptyline and imipramine induced weight gain of 1.3–2.9 lbs per month, and weight increased linearly overtime	n=40 Average of 6-months treatment
Body weight gain during nortriptyline (TCA) or escitalopram (SSRI) treatment94	Nortriptyline First 12 weeks: +1.22 kg, BMI score increase of 0.44 After 6 months: +1.82 kg, BMI score increase of 0.64 Escitalopram First 12 weeks: +0.14 kg, BMI score increase of 0.05 6 Months: +0.34 kg, BMI score increase of 0.12	n=630 12 weeks and 6 months of treatment
Weight gain associated with tricyclic or SSRI treatment88	Average weight gain of 1.4 kg (2.5%) in the control group and 2.5 kg (4.3%) among users of 200 defined daily doses of antidepressant	n=5537 4 years

Abbreviations: BMI, body mass index; MetS, metabolic syndrome; NHPS, National Population Health Survey; OFC, a combination of olanzapine and fluoxetine; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclics.