Depression is a leading cause of disability in the United States and with so many different signs and symptoms, it can be difficult to diagnose. In fact there are many other disorders that mimic depression including hypothyroidism, vitamin D deficiency, fibromyalgia, diabetes, dementia, and chronic fatigue syndrome. Chronic fatigue syndrome is a medical diagnosis with an unknown cause (but most likely viral) that affects young and middle aged adults primarily in the United States. Individuals with chronic fatigue syndrome often report feelings of excessive tiredness, lapses in short-term memory and feelings of depression secondary to their excessive fatigue.
Chronic fatigue syndrome
Chronic fatigue syndrome (CFS) was initially named myalgic encephalomyelitis because the essential clinical features of CFS included both an encephalitic component (manifesting as cognitive difficulties) and a skeletal muscle component (manifesting as chronic fatigue). CFS is a medical diagnosis and not a psychiatric diagnosis therefore it is not recognized in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Chronic fatigue syndrome is characterized as a chronic state of fatigue that persists for at least six months in duration with the presence of cognitive difficulties. It is usually preceded by a viral illness but no underlying clear cut etiology is usually found and most other medical and psychiatric conditions must be rules out as this is primarily a clinical diagnosis and diagnosis of exclusion. The following are signs and symptoms associated with chronic fatigue syndrome:
- A lapse in short term memory but an intact long term memory
- Problems concentrating
- Unable to perform everyday tasks due to extreme fatigue
- Preceding viral infection
- Inability to say or find a particular word during normal speech
- Postexertional fatigue (feeling excessively tired after doing relatively normal tasks)
- Non-restorative sleep
- Depression because of the inability to perform everyday tasks
Major depressive disorder
Major depressive disorder is a mood disorder that affects more than 15 million adults in the United States. Individuals with depression many not even report depressive signs and symptoms and instead present to their physician for somatic or physical symptoms such as headaches, abdominal pain, muscle pain, and fatigue. Individuals may also complain of irritability or problems concentrating. Adolescents with major depression disorder may present with a decline in school performance, substance abuse, irritability or social withdrawal and elderly individuals often present with confusion or a decline in general functioning. This disorder may be difficult to initially diagnose, as many individuals may not show the clear-cut signs and symptoms of depression. According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM V), at least five of the following symptoms must be present within a two-week period with at least one of the symptoms being depressed mood. Additionally these symptoms must cause apparent distress in social and occupational functioning.
- Sleep disturbance
- Loss of interest in activities
- Feelings of guilt
- Loss of energy
- Difficulty concentrating
- Change in appetite
- Psychomotor agitation
- Suicide ideations
Differences and similarities between chronic fatigue syndrome and depression
Depression differs from chronic fatigue syndrome in many ways but also shares some commonalities. First, major depressive disorder is a psychological disorder that is not preceded by a viral illness and symptoms of depression must be longstanding for at least six months. Individuals with chronic fatigue disorder may have signs and symptoms of depression secondary to not being able to be productive but there is no standing history of depression. The primary signs and symptoms of depression include sad mood, social isolation and negative thoughts and although fatigue and poor concentration are symptoms, they are not the primary symptoms like they are in chronic fatigue disorder. So although there is some overlap in the two disorders, there are many subtle differences that should be picked up by a healthcare provider.