Diet & Depression

Diet and Depression

Depression diets were first described in the 2nd millennium BCE. Special diets (including donkey’s milk!) were prescribed in ancient Greece and Rome; and nutritionists have since been looking for possible links between diet and depression. With 350 million sufferers globally; the search for effective treatment and prevention of depression is still on. 

Link between diet and depression

Many people with moderate and severe depression are known to consume food of poor nutritional quality. This is often due to the symptoms of depression itself; such as the loss of appetite; lack of interest in day to day activities; and lack of motivation for self-care. Age, living alone, irregular and hectic work schedules, socio-economic status, cultural and religious taboos may further affect the quality of the diet.

The food we eat is broken down to its simplest forms in the intestines. The nutrients are then used to provide energy for the body and brain; and to synthesize essential compounds. Among them are the hormones and neurotransmitters which act as messengers in the brain. A lack of supply in the diet will therefore certainly affect production of these chemicals.

Bacteria present in our gut help in the breakdown, absorption and even in the synthesis of some of these essential compounds. The type of food we eat, in turn, affects the type of microbes in the gut Thus, there seems to be an important link between what we eat; the microbes in our gut, and all aspects of our health, including mental health.

What are the essential elements of the depression diet?

A diet including whole grains, leafy and colourful vegetables, fruits, nuts and legumes, high quality protein in the form of seafood, chicken and lean meats has been found to be positively correlated to mental health.

• Whole grains contain complex carbohydrates, which are linked to the mood boosting neurotransmitter serotonin. Complex carbohydrates break down slowly in the body, lead to steady levels of glucose in the blood and thus avoid mood fluctuations.
• Proteins of high quality as in egg whites, chicken, fish, milk products, soy products, beans and legumes are the source of the amino acid tryptophan, which is the precursor of serotonin. Trace minerals - selenium, chromium, and zinc, present in beans, legumes, lean meats, dairy products and whole grains are also linked to the brain and mental health.
• Anti-oxidants combat the free radicals which cause cell damage in the brain. Rich sources of anti-oxidants are coloured vegetables such as pumpkin, carrots, spinach(containing beta carotene), citrus fruits, tomato, potato, guava (containing Vit C); nuts, seeds and vegetable oils (having Vit E)
• Omega 3 fatty acids play an important role in mental health and may be used as a supplement in depression. Mammals do not synthesize omega 3 fatty acids and depend on dietary sources which include fatty fish, flaxseeds, and nuts (especially walnuts).

Vitamin D and Depression

Low Vitamin D levels are often seen in depression, but no definite causal association has yet been found. Depression itself may cause low Vitamin D levels, as people with depression are less likely to go outdoors. It would be sensible to correct Vitamin D levels and include fish oils, fish and dairy products in the diet, but use supplements with caution.

In conclusion

Depression cannot be prevented or cured by a special diet. However, a sensible diet including whole grains, proteins, fresh fruits and vegetables will keep you looking and feeling good. Limiting refined starches (the so-called “beige diet” pasta, pizza, bread, baked goods), caffeine, and alcohol also has a beneficial effect on mood. Do not go for any extreme or ‘fad’ diet. It will only add further to your stress and anxiety. A recent study of depression patients shows that diet does not prevent, cure or relieve depression, but diet may have a significant role in recovery and prevention of depression

Diet and dietary supplements are never a substitute for a therapist.

References:

1. Democritus Junior (Robert Burton). Anatomy of Melancholy (1652). Project Gutenberg release date January 13, 2004. Accessed 08-May-2017
   
2. Rashmi Nemade, Natalie Staats Reiss, Mark Dombeck. Historical Understandings Of Depression. Sep 19, 2007. Accessed 08-May-17
3. Rao TSS, Asha MR, Ramesh BN, Rao KSJ. Understanding nutrition, depression and mental illnesses. Indian Journal of Psychiatry. 2008;50(2):77-82. doi:10.4103/0019-5545.42391. Accessed 08-May-2017
4. Drew Ramsey. Prescribing a Diet to Treat Depression. February 03, 2017. Accessed 08-May-2017

Did you know? Many celebrities and historical figures have suffered from depression. Writer JK Rowling, musicians and singers Lady Gaga, Bruce Springstein, Sheryl Crow, actors Robin Williams, Jim Carey, Gwyneth Paltrow, astronaut Edwin ‘Buzz’ Aldrin suffered from depression. Abraham Lincoln, also a sufferer, once said “If what I feel were equally distributed to the whole human family, there would not be one cheerful face on earth.”

Forgetfulness and Memory Loss at Work

Memory loss results from disruption at any of these processes

Forgetfulness and Memory Loss 

Forgetfulness or failure to remember information, is a common complaint. All of us have at some time or the other forgotten to make that important call, to pick up some items from the store, an anniversary or birthday, or a colleague’s name. Students forget what they have “learnt” during exams. We often can’t remember where we have left our car keys, our wallet or that important document. Is it normal? And more importantly; when do we need to seek help?

Forgetfulness or memory loss and difficulty concentrating are common symptoms of mental health disorders. This is specially so in depression, anxiety disorders, ADHD (Attention Deficit Hyperactivity Disorder), and dementias as shown in the examples below.

A young working professional seeks help for increased forgetfulness and poor ability to focus at work. Further probing reveals decreased interest in doing things at work and home. She is also irritable, depressed and her sleep is disturbed. These symptoms of low mood can exist in the background of memory loss and problems with focus.

A student during exams has high anxiety causing memory loss. She cannot recall the answer to a certain question. She gets nervous. This causes her to make mistakes in the next question. She tends to panic; fail to recall what she studied. This vicious cycle is common in anxiety disorders and can manifest as problems with concentration, memory and forgetfulness.

An older person does not just forget the name of his neighbour (something that may happen to any of us); but also who she is. He has problems using money, and with shopping. Difficulties at work manifest towards the end of the career. Dementias affect the aged; cause memory loss and affect the context of the memory. 

A young professional has problems organising and completing projects at work. There may be a history of attention and academic problems in school. Working memory gaps are common in this group. ADHD is a common cause of this problem in adults.

Memory Processing in the Brain

To understand further, it helps to know in brief how memory works. It is a 3 stage process

Encoding

The stage when sounds, images and other sensations are given meaning is called encoding. Sensations are coded electrically for access by other brain areas. (We hear a catchy song from a new movie).

Storage

The process of association or tagging the input with other bits of data to make it persist. The song thus gets stored in our long term memory. Initially, the song remains for a very short while. At this point it is in our working or short term memory. It is encoded. However, we forget the song as the next scene unfolds on screen. The song is repeated at the end of the movie; someone hums the song as we leave the hall. The visuals of the song, and the feelings evoked, the fact that it was a famous actor, then reinforce the memory and makes it persist.

Retrieval

When we need to use this stored data, the brain fishes it out from its long term memory. The more the associations or tags we formed earlier, the more easily the brain can access the information.

Problems in memory can therefore occur at any of these stages. Many of these occur at the stage of encoding because we are simply not paying attention; and many other distractions are vying for our focus at the same time. (e.g checking our FB messages while studying). The brain does not multi-task, it can only do one thing at a time.

Repetition, rehearsal and organisation help in fixing and storage of long term memory. The more widespread and elaborate the connections, and the more data available about an input, the more the connections formed by the brain, and the easier it is for the brain to retrieve the information when required. Many cases of forgetting are due to retrieval failures. The information is there in long term memory but we are unable to access it. This is why we can recall certain things at a later date.

Depression affects memory in many ways. Being unable to concentrate is a symptom of depression. Repeated depressive thoughts also block the learning process through distraction. This affects the stage of encoding. Disturbed sleep which is a common symptom in depression hampers fixing into long term memory.
Forgetfulness is common in ADHD of adults. ADHD lowers the power to focus. The person is easily distracted. The attention span is reduced. This impairs short term or working memory. ADHD persists in up to 40% of aduts.
Anxiety gives rise to pointless thoughts (“my father will be so angry if I don't crack this exam”) which frustrates attempts to retrieve the matter learned. The anxiety provoking thoughts distract from the text which is being studied and impedes the  encoding process.
In dementia there is destruction and loss of brain cells. Dementia blocks all stages of the memory and learning process. The process is not reversible.

Forgetfulness and Memory Loss – when to seek help?

• When it affects our work, or the quality of our work
• When the failure to learn and recall affects our daily activities and functioning
• When there are also problems including sleep, appetite, inter-personal or behaviour changes.
• When it is strange - leaving keys in the fridge 
• When it can harm - often leaving cooking burner on, leaving doors unlocked at night

In normal forgetfulness, the person may recall the memory when some cues are given. The memories were encoded, they just needed some reminder to access them. In clinical disorders resulting in memory loss the memories were never laid down in the first place, or the storage structures in the brain are destroyed. Access to these memories may not be possible. 

References

1. Brydges CR, Ozolnieks KL, Roberts G. Working memory - not processing speed - mediates fluid intelligence deficits associated with attention deficit/hyperactivity disorder symptoms. J Neuropsychol. 2015 Dec 31. doi: 10.1111/jnp.12096. [Epub ahead of print]