Sir: Obsessing and dwelling (or ruminating) are often used interchangeably to describe types of worrying within the context of anxiety and depressive disorders. However, they are probably different constructs, which may involve two distinctly different brain neurotransmitter systems. It is plausible that nature teleologically designed two distinct reflective systems: one to process real events that have happened and another to predict future harmful events. Obsessing refers to worrying about things yet to happen or are only hypothetical and usually unlikely to happen. Dwelling or ruminating refers to worry or concern or preoccupation with things that have already happened or are realistic concerns. The importance of this distinction lies in its predictive value with respect to response to antidepressants with differing receptor specificity. I have observed that excessive obsessing is more responsive to serotonergic agents. Conversely dwelling / ruminating responds best to medications that have at least some noradrenergic effects. Patients suffering from both obsessing and ruminating may do better on a dual acting medication or combination of medications. The following brief case examples help to illustrate this.
Case report. BM is a 20 y/o male who had been treated successfully for classic and severe obsessive-compulsive disorder with fluoxetine 80mg (This theoretically provided mostly serotonergic effects but some noradrenergic effects due to the high dose). He was changed to escitalapram 40mg (presumably devoid of noradreneric effects) because of side effects. He did well initially for a few months but he began to ruminate excessively about premature hair loss. This at first seemed like a return of his obsessing, but he indeed had significant male pattern balding over the prior few years. Since this was a realistic rumination about something that has happened, buproprion SR 150mg (a non-serotonergic, primarily noradrenergic medication) was added with a resultant robust reduction in this symptom.
Case report. JYis a 50 y/o woman who presented with depression, overeating, crying and emotional blunting. She had been on citalapram 20mg which “pooped-out” after several months. A change to escitalopram 10mg gave some improvement but her mood was still down. An initial elicitation of symptoms revealed emotional blunting, fatigue at the end of the day and well controlled anxiety. This symptom pattern would have led me to consider augmentation with a noradrenergic agent. However, more careful questioning noted that her depression was focused on her worrying about her future in view of her unhappy marriage and her self described irrational thoughts of divorcing her husband. Rather than augmenting the escitalopram, I increased it to 20mg with dramatic improvement in mood and fatigue. The marital situation was unchanged but she was not worrying as much about her future. Instead she was agreeing to begin psychotherapy to work on realistic future goals and her unrealistically negative view of her husband.
Case report. GO was a 55 y/o woman presenting with panic and depression as well as arthritis and heart disease. Prior trials of paroxetine and escitalopram produced fatigue and worsening of depression. A trial of buproprion XL gave dramatic improvement in mood and anxiety. More careful questioning of her panic revealed that she did not have classic fear of dying or loss of control, but was dwelling on the realistic loss of function due to her medical problems. These “panic” attacks had a more gradual onset and lasted up to two hours.
Stahl proposed that serotonin might mediate symptoms of anxiety and obsessing, while norepinephine (NE) might mediate energy, concentration and drive. However, anxiety has been successfully treated in some patients by SSRI’s, SNRI’s and in some cases just noradrenergic agents. I am proposing subdividing the worrying component of anxiety symptoms into two types that have predictive value in medication choice. This hypothesis would predict that patients who ruminate about real, past traumas or losses would respond preferentially to a medication that has some significant noradrenergic effect. On the other hand, patients who are fearful about imagined or hypothetical things that may happen to them or obsess unrealistically about their futures will need a serotonergic agent. Patients with OCD and panic obsess about calamities that will befall them if they don’t take some irrational or excessive precaution. These patients respond well to SSRI’s. Buproprion, a noradrenergic medication, has been effective in treating excessive grief associated with a real loss. Clearly there are patients who have both symptoms and they will need dual acting medications.
Patients with ruminations share some features with patients with ADHD in their difficulty concentrating enough to solve a real problem. The ruminative patient can’t seem to organize their thinking and work out a logical solution. ADHD has been traditionally treated with NE medications such as stimulants, desipramine or atomoxetine. In obsessing there is a hyper focusing, albeit on irrelevant or irrational items. The obsessive patient is hyper organized to the extent of fantasizing too many scenarios that are illogical. Obsessive compulsive disorder usually calls for treatment with a serotonergic agent.
This predictive hypothesis may not hold for patients who have bipolar disorder or psychosis. In fact when it doesn’t seem to apply, I look more carefully for a bipolar spectrum disorder. This is a testable hypothesis and I encourage research to test its validity.
Baldwin et.al., proposed that anxiety and depression may exist on a continuum with disturbances in serotonin and norepinephrine. It is conceivable that some of the debate over the superiority of dual acting (SNRIs) versus single acting (SSRIs, NRI) may be confounded by the failure to separate these two types of worry when rating patients symptoms of anxiety and depression. Patients with only obsessive worry may find a medication with some NE effect less calming than a pure SSRI. Whereas patients with some dwelling anxiety may need an SNRI for more complete remission of symptoms. The fact that some SSRI’s may be less selective than others may also have obscured this distinction.
Neil R. Liebowitz, M.D.
Connecticut Anxiety & Depression Treatment Center
Assistant Clinical Professor of Psychiatry
University of Connecticut, Farmington, CT USA
|Click on these buttons to visit our journals|
All pages copyright ©Priory Lodge Education Ltd 1994-2005.
First Published June 2005