Mood and Anxiety Disorders: Part One (the Science)
Hallo, darlings. I feel like we had so much fun in our previous discussion on depression that we should do it again! My last post came from a personal place and was definitely one-sided. Well, I’ve decided we need to split the difference between the science behind depression and speaking with sufferers. And not just depression, but anxiety disorders as well. Mood and anxiety disorders have numerous overlapping symptoms and often having one will lead to eventually suffering from the other.
I mentioned last time that depression isn’t an emotion—it’s a state being. So now, I’ll back that up with the—drumroll, please, Dave—science around depression and anxiety. As with any kind of neuroscience, nothing is completely concrete here. Every day we are learning more about the brain. That said, the clinical studies included in this post reflect the most in-depth researched and medically accepted causes for depression and anxiety.
Serotonergic and Noradrenergic Systems
The prevailing science behind depression and anxiety disorders centers around serotonin and norepinephrine dysfunction. When you first get on an antidepressant, chances are it’s an SSRI (selective serotonin reuptake inhibitor) or SNRI (serotonin and norepinephrine reuptake inhibitor), which is usually prescribed before MAOI (monoamine oxidase inhibitor) or atypical antidepressants. Depending on who you talk to, SSRIs—though having the least side effects—are probably the least viable option long term. In an overview in Depression and Anxiety, Charles B. Nemeroff, M.D., Ph.D., states: “There has been increasing evidence […] that antidepressants that inhibit both norepinephrine and serotonin reuptake (SNRI) are more effective in severe and refractory depression than those that inhibit uptake of a single monoamine neurotransmitter. In addition, patients with major depression treated with dual reuptake inhibitors may achieve remission more frequently than those treated with single monoamine reuptake inhibitors.” Conversely, depressive episodes for patients on SSRIs often hit harder. In the event you think you have depression and are about to look for treatment, be ready for a whirlwind of ups and downs before you get the right meds.
Of course, there’s more to it than just serotonin and norepinephrine dysfunction. In Role of Serotonergic and Noradrenergic Systems in the Pathophysiology of Depression and Anxiety Disorders, Nemeroff and Kerry J. Ressler explain: “There is abundant evidence for abnormalities of the norepinephrine (NE) and serotonin (5HT) neurotransmitter systems in depression and anxiety disorders. […] The underlying causes of these disorders, however, are less likely to be found within the NE and 5HT systems, per se. Rather their dysfunction is likely due to their role in modulating, and being modulated by, other neurobiologic systems that together mediate the symptoms of affective illness.”
It’s important not to think of depression and anxiety as something you can throw pills at and be done with. These illnesses are more complicated than that, and their origins are not singular. Continues Nemeroff and Ressler: “Disrupted cortical regulation may mediate impaired concentration and memory, together with uncontrollable worry. Hypothalamic abnormalities likely contribute to altered appetite, libido, and autonomic symptoms. Thalamic and brainstem dysregulation contributes to altered sleep and arousal states. Finally, abnormal modulation of cortical-hippocampal-amygdala pathways may contribute to chronically hypersensitive stress and fear responses, possibly mediating features of anxiety, anhedonia, aggression, and affective dyscontrol.” When dealing with depression and anxiety, it is important to rule out symptoms that are caused by a secondary problem.
It’s in Your Genes … And Environment
I’m assuming we all know the nature vs nurture argument, especially pertaining to mental illnesses. And, as with most cases to which this argument can be applied, the likelihood of suffering depression or anxiety are both attributed to nature and nurture. Nemeroff and Elizabeth B. Binder, M.D., Ph.D, explain: “Susceptibility to depressive or anxiety disorders is now well established to be due to the combined effect of genes and the environment, with heritability estimates for these disorders ranging from about 30% to 40%. The CRF system, being highly responsive to the environment, has been posited to serve as a key interface between environmental stressors and the development of depression.”
Research based on Hopelessness Theory (HT) and Beck’s Theory (BT) further backs up this claim. The team behind Cognitive Vulnerability-Stress Theories of Depression: Examining Affective Specificity in the Prediction of Depression Versus Anxiety in Three Prospective Studies posits that: “The cognitive vulnerability-stress component of HT, a depressogenic cognitive style is hypothesized to interact with negative life events to contribute to increases in depressive symptoms. In HT cognitive vulnerability is conceptualized as a tendency to make negative inferences about the cause […] consequences, and meaning for one’s self-concept, of a negative life event. Similarly, BT posits a vulnerability-stress component in which dysfunctional attitudes are hypothesized to interact with negative events to contribute to elevations of depressive symptoms. In BT, cognitive vulnerability is conceptualized as depressive self-schemas containing dysfunctional attitudes, such as one’s worth derived from being perfect or needing approval from others.”
For non-sufferers, it is important to realize that depression and anxiety are not normal emotional responses. They are abnormal and out of the sufferer’s control. Saying something like, “Relax,” or, “You’re overreacting,” to someone who suffers from depression or anxiety only serves to alienate the sufferer more.
I wanted part one of this series to really show that depression and anxiety are not personality defects, not cries for attention, not someone being overly dramatic or sensitive. Although, sure, there are some of those types of people scattered about. Depression and anxiety stem from the very genetic level of the sufferer. And from there, it’s a cycle. You’re genetically predisposed to negativity and so you find it everywhere, which doubles down on depressive or anxious episodes.
Part two of this post is going to balance out the science with the human aspect. We’ll be getting a peek into the lives and struggles of individuals suffering from depression, anxiety, or both.
Be on the lookout for part two next Monday!