1. What is Seasonal affective disorder (SAD)? How does it occur? 

SAD is a type of recurring major depression with a seasonal pattern occurring most commonly in autumn and winter [when it is called winter type SAD] but also occasionally during summer [when it is termed SAD – summer type]. It occurs because people with SAD express a combination of excess melatonin production and decreased serotonin concentration in their brains which leads to impaired capacity of their circadian rhythms [the body’s 24-hour biological clock] to respond to seasonal changes in day length. Deficits in vitamin D which results from reduces sunlight exposure in winter may exacerbate these problems because vitamin D is believed to promote serotonin activity. 

2. Which group of people are more susceptible to Seasonal affective disorder (SAD)? 

SAD is four times more common in women than men. It is more common in those living farthest from the equator in northern latitudes. It is also commonly seen in patients with pre-existing mental health conditions such as major depressive disorder or Bipolar disorder. Professionals who do shift work may also be at particular risk.

3. What are the symptoms of Seasonal affective disorder (SAD)? 

Symptoms of major depression may include:

• Having a low/sad mood most of the day, nearly every day  

• Losing interest in activities you once enjoyed  

• Having problems with sleep, appetite or energy  

• Feeling hopeless or worthless  

• Having frequent thoughts of death or suicide  

4. Additional specific symptoms for winter-pattern SAD 

• Oversleeping (hypersomnia)  

• Overeating, particularly with a craving for carbohydrates  

• Weight gain

• Social withdrawal (feeling like “hibernating”)  

5. Specific symptoms for summer-pattern SAD

• Trouble sleeping (insomnia)  

• Poor appetite, leading to weight loss  

• Restlessness and agitation  

• Anxiety 

• Episodes of violent behaviour.

6. Treatment for SAD 

The three most commonly use methods of treatment for SAD include:

• Bright Light Therapy – given daily early in the morning using a light box 

• Antidepressant Medications from the SSRI class as well as the drug Bupropion 

• Psychotherapy 

• Vitamin D 

7. When to seek professional mental health support 

SAD can occur in al mild fashion when it is called “Winter blues”. This may not be severe enough to cause difficulty in interpersonal or occupational functioning. However more severe or prolonged symptoms of sufficient magnitude [and especially if accompanied by thoughts of self-harm] to impair interpersonal or occupational functioning almost always warrant a consultation with a mental health professional.  

8. Diagnosis of SAD

Like in any other psychological condition a person with suspected SAD is initially queried about the symptoms, onset, duration, impact, precipitants and any other past medical or family psychiatric illnesses and treatments. A thorough review of symptoms of all major psychiatric conditions is also conducted. He/she is then taken through a mental state examination – the equivalent of a physical examination to assess current mood, emotional and cognitive state. Information is also gathered from a close family member or friend. Laboratory tests may be ordered if needed. The final diagnosis is arrived at adhering to standard classification systems [DSM or ICD] and the treatment plan formulated jointly in conjunction with the person and/or family.  

What is the status of Seasonal affective disorder (SAD) in India? How is the status of the prevalence of Seasonal affective disorder (SAD) different from other countries? What are the possible causes of these trends? 

SAD is less well studied in India compared to other Western countries. While the community prevalence of SAD in North America is around 5% there have only been a few clinic/hospital-based studies from Northern India. While a study from Kashmir reported winter type SAD as being more common, the other study from Chandigarh reported summer type SAD as being more common [5.7% of all cases seen in that hospital]. Mania predominant SAD was also commonly reported in the Chandigarh study but not in the Kashmir study. The climatic conditions [with harsh, snowy winters in Kashmir and extreme summer heat in Chandigarh and adjoining North India] and the latitudinal location of the places were cited as the possible reasons for these divergent results.