Depression – Important Differential Diagnoses
1. Bipolar Disorder – always ask patients if they have had a manic or hypomanic episode
2. Borderline Personality Disorder – duration of low mood is not sustained and mood instability is prominent. Both depression and Borderline personality disorder may co-exist.
3. Adjustment Disorder with Depressed Mood – Mild features of depression in context of identifiable stressor, eg grief
4. Anxiety – Very common co-morbidity in depression
5. Drug Induced Mood Disorder
Alcohol-Induced Mood Disorder is common
Cannabis is associated with “amotivational syndrome”
6. Obsessive Compulsive Disorder (OCD)
OCD can lead to secondary depression
Depression can exacerbate OCD
e.g. Hypothyroidism, Multiple Sclerosis, Vit B 12 deficiency, Addison’s disease, medications etc.
IMPORTANT POINTS IN DEPRESSION FOR CLINICAL PRACTICE
1.If patient has had experiences of low mood all their life, then consider the possibility of Borderline Personality Disorder or Dysthymia
2. In older (> 55) patients depression presents atypically.
- Psychomotor retardation
- Hypochondriacal overvalued/delusions
- Obsessive-compulsive symptoms
- Agitated depression
3. Vascular Depression or early sub-cortical dementia is common in late life depression
4. Vascular depression is associated with White Matter Hyperintensities (WMH’s) as shown in the below image. These can impact on cognitive function making the individual more vulnerable to stressors. It is important to treat vascular risk factors such as Diabetes, Hypertension and address smoking and alcohol use.