Abstract
Gordon Parker, Sydney, Australia:
Antidepressant drugs are recognized as causing ‘mood switches’. In prescribing the ‘newer’ antidepressants to depressed patients with a bipolar history, I have rarely, however, had ‘switching’ reported. More importantly, following commencement of an SRRI or SNRI, many patients have had their mood swings attenuate. In the last year I have had 10 bipolar patients acknowledge this phenomenon on specific questioning, and detail their characteristics.
Five had been commenced on antidepressants by me for the first time, 4 had had one previous antidepressant only and one had had numerous antidepressants (including SSRI) and mood stabilizers. Six were female. Their mean age was 31, and estimated mean ages for onset of mood disturbance were 19 for the first ‘high’ and 24 for the first depressive episode. Their past ‘highs’ were distinctive and observable by others. None had had clear-cut psychotic features during a ‘high’, but three had had episodes of psychotic depression. Eight had a first-degree relative with depression (three of these having a bipolar illness). One patient had experienced highs lasting months; for the remainder, ‘highs’ lasted from hours to days. Three had previously taken stimulants (i.e. amphetamines, cocaine or ecstasy), but for two, this followed onset of a bipolar history. Only one described their initial ‘high’ occurring after commencing an antidepressant.
In terms of the medications associated with attenuation of mood swings, six of the eight had received citalopram, two venlafaxine, one fluvoxamine and one paroxetine. The dose for these was within the standard range for nine, and low for the tenth patient, as higher doses caused tiredness.
All had their depressive episode improve or remit. The pattern change for ‘highs’ was either a decrease in frequency, severity and/or duration. Those who reported the clearest reduction in frequency and/or severity were likely to report distinct improvement across the same parameters for their ‘highs’, suggesting overall stabilization.
A review of the literature identifies ‘manic switching’ in association with all the newer antidepressants. However, the ‘switch’ rate appears distinctly lower than for the older antidepressants and may not be causal. Peet [1] reported that the switch rate in bipolar patients treated with the paroxetine, sertraline, fluvoxamine and fluoxetine was equivalent to that in placebo-treated patients (3.7% vs 4.2%) and less than those treated with a tricyclic (11.2%), while pretrial and postmarketing data from Wyeth suggest that switching is rare in those treated with the venlafaxine. No studies have been undertaken, to determine if such drugs have any attenuation effect on bipolar disorder.
This report seeks to determine if other Australasian clinicians have observed mood stabilizing effects with the ‘newer’ antidepressants. If this observation is confirmed, studies would be welcomed in light of the many limitations to standard mood stabilizers.