Depression is a mental illness that very often has physical effects. There are several potential ways in which depression affects movement, and this post will explore low energy, psychomotor retardation, and leaden paralysis. These symptoms can occur in both bipolar and unipolar depression.
Fatigue is one of the most common symptoms of depression. Fatigue can involve low energy, decreased endurance, sluggishness, and weakness, and can spill over into mental effects including decreased motivation. However, fatigue is a very non-specific symptom that can occur in the context of many other health conditions, and most healthy people will experience mild fatigue from time to time following periods of high activity.
In people who get partially but not fully better from a depressive episode, fatigue is one of the most common residual symptoms.
Among antidepressants, bupropion is more likely to be helpful with fatigue. While most antidepressants affect serotonin and sometimes norepinephrine, bupropion affects norepinephrine and dopamine, and it tends to be more activating. Stimulant medications are also an option.
Psychomotor retardation involves a slowing of movement and thoughts. It’s most common in depression with melancholic features and psychotic features.
The slowness is objectively observable by others. It’s most noticeable in movements closer to the core, and it would be more visible when someone is walking, for example, rather than making small hand movements. For me, walking is significantly impacted, while I don’t notice a major change in my typing.
Other effects of psychomotor retardation can include slowed speech, minimal eye contact, and flat affect (i.e. a lack of facial expressiveness of emotions). The post What Is… Psychomotor Retardation goes into more detail.
While the biological basis is uncertain, several possibilities have been identified. Dopamine activity in an area of the brain called the basal ganglia appears to play a role. There may also be abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis, which is involved in the release of the stress hormone cortisol.
Electroconvulsive therapy (ECT) seems to be one of the most effective treatments for this particular symptom of depression. Among the different antidepressant classes, tricyclics may be the most effective.
Leaden paralysis tends to occur in depression with atypical features. The subtype is named that way not because it’s uncommon, but because it involves increased appetite, increased sleep, and mood reactivity to positive events, which is different from the pattern of decreased appetite, insomnia, and anhedonia that’s somewhat more common in depression. Atypical depression also tends to be associated with a pattern of sensitivity to interpersonal rejection.
About half of people with atypical depression experience leaden paralysis, which involves a feeling of heaviness and being weighed down in the limbs, with significant fatigue. Greater leaden paralysis is associated with worse depression symptoms overall and greater chronicity. Leaden paralysis is more common in females and adults over 30, as well as people who also have an anxiety disorder.
While the biological mechanism behind this is unclear, there’s some indication it may be related to disruptions in the HPA axis or changes in the balance between left and right brain functioning. MAOI (monoamine oxidase inhibitor) antidepressants tend to work particularly well, although they’re not the first line of treatment because of the potential side effects and the need for dietary restrictions.
What’s the difference?
Although there’s certainly overlap in the different ways that depression affects movement, the three are seen as discrete symptoms. It’s probably fairly safe to say that most people who experience depressive episodes as part of their illness have experienced fatigue as a symptom at one time or another. Leaden paralysis and psychomotor retardation are quite a bit less common.
I can’t speak to what leaden paralysis feels like, since I haven’t experienced it, but the key element is a feeling of lead weights in the arms and legs exerting a downward pull. This produces fatigue rather than being something that occurs as a result of fatigue.
Psychomotor retardation feels like walking through molasses. It doesn’t feel like I could go faster if only I had more energy. It’s like one of those speed-restricted vehicles—my brain has set a top speed my body can move at, and I simply can’t go any faster than that. I find the slow movement to be quite tiring, but as with the leaden paralysis, fatigue is an aftereffect rather than the cause. It affects my speech, too; my best friend has said that when he calls me, he can tell within seconds from my voice if I’m not feeling well.
The physicality of mental illness
While the difference between these three symptoms matters somewhat in terms of treatment, what I find most interesting is how physical the illness is, and in particular how much depression affects movement. These symptoms all fall under the umbrella of a major depressive episode in the DSM-5, but I wonder when/if science will be able to narrow it down a little more.
Do you experience any of these symptoms?
- Buyudura, J.S. et al. (2011). Psychomotor retardation in depression: Biological underpinnings, measures, and treatment. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 35(2), 395-409.
- Posternak, M. A., & Zimmerman, M. (2001). Symptoms of atypical depression. Psychiatry Research, 104(2), 175-181.
- Quitkin, F.M. (2002). Depression with Atypical Features: Diagnostic Validity, Prevalence, and Treatment. The Primary Care Companion to the Journal of Clinical Psychiatry, 4(3), 94-99.
- Singh, T., & Williams, K. (2006). Atypical depression. Psychiatry MMC, 3(4), 33-39.
- Targum, S.D, & Fava, M. (2011). Fatigue as a residual symptom of depression. Innovations in Clinical Neuroscience, 8(10), 40-43.