The public health impact of antidepressants: An instrumental variable analysis

BackgroundThere has been a marked increase in antidepressant medication prescription and use over the past three decades with unclear effects on the mental health status of the population. This study examined the impact of expansion of antidepressant use on prevalence and characteristics of depression and suicidal ideations in the community.MethodInstrumental variable models were used to assess the impact of antidepressant treatments on the prevalence of depressive episodes, mixed anxiety and depression states and suicidal ideations in 22,845 participants of the 1993, 2000 and 2007 National surveys of psychiatric morbidity of Great Britain who were between 16 and 64 years of age.ResultsIncreased prevalence of antidepressant treatment did not impact the prevalence of depressive episodes or mixed anxiety and depression states. However, antidepressant treatment was associated with decreased prevalence of severe and, to a lesser extent, mild depressive episodes and suicidal ideations and a corresponding increase in prevalence of moderate depressive episodes.LimitationsThe data were cross-sectional and based on self-report of symptoms in the past month and current medication use with no information on dose and duration of medication treatment.ConclusionsExpansion of antidepressant treatments in recent years has not changed the community prevalence of depression overall, but it has reduced the prevalence of more severe depression and suicidal ideations. The findings call for better targeting and more judicious use of antidepressants in cases of more severe depressive episodes which are more likely to respond to such treatments.