Thyroid hormone,Hyper and Hypo thyroidism and Change of mood

Patients with hyper or hypo thyroidism usually feel very agitated ,out of control,angry and crying about things that could be ordinarily handle with ease.In this case,that is the thyroid hormone that can be blamed for this kind of behavior.                                                                                                                                                                          Thyroid disorders can  have noticeable impact on one's energy level and mood.Hypothyroidism tends to make people feel tired,sluggish and depressed.Hyperthyroidism can cause anxiety problem,restlessness and irritability.                                                                                                                                                                       
The link between thyroid function ,depression and anger has long been recognized. Patient's with thyroid disorders are more prone to develop depressive symptoms and conversely depression may be accompanied by various subtle thyroid abnormalities.                                                                                                                                    Imbalance of thyroid hormone:As blood flows through the pituitary gland, its cells detect if there are adequate T4 levels in the body.If the T4 level is adequate ,the pituitary sends the appropriate amount of TSH to the thyroid to maintain T4 levels in the normal range .If one's T4 level is too low,the pituitary sends more TSH out telling the thyroid to make more T4 .If one's T4 level is high,the pituitary sends less TSH out,telling the thyroid gland to make less T4.As easy way to remember how the thyroid works -think about supply and demand.As T4 level falls,the TSH rises .As T4 level rises ,the TSH falls.T4( Tyroxine) and  T3(Triiodothyronine) are the bound forms .fT4 and fT3 are the free and biologically active forms.And TSH is the thyroid stimulating hormone. 

                                                                                                                    
 Ranges of thyroid  hormone for thyroid function test:

             1.TSH -0.4mU/L(milliunit per liter) to 4.00 mU/L

             2.T4 is from 5.0 to 12 µg/dL (microgram per deciliter)

             3.T3 is from 0.8 to 2.0 ng/mL(nanogram per milliliter)

             4.fT4 is from 9.0 to 25.0 pmol/L (picomoles per liter)

             5.fT3 is from 3.5 to 7.8 pmol/L

             6.Anti TPO(anti thyroid peroxidase antibody): <34.0 IU/mL
             7.Thyroglobulin - 3 to 40 ng/mL 

             There may be  a slight variation in the reference range depending on the laboratory.                                            

         Test results that are not between the range: A high TSH level with a low fT4 :Hypothyroidism(under-active thyroid).A low TSH level with a high fT4 :Hyperthyroidsm (over-active thyroid).Abnormal TSH level together with normal fT4 level indicate the risk of developing a thyroid disorder.A low TSH  level together with a low fT4 level can indicate a disorder of the pituitary gland.Thyroid function tests can be influenced by medications and illnesses.If one's TSH is above the range with normal T4 this may prompt physician to test serum anti-thyroid peroxidase antibodies (anti-TPO ).If these antibodies are present ,it may indicate an auto immune thyroid disorder.

                         Thyroid function and change in mood:The mechanism underlying the interaction between thyroid function and depression remain to further clarified.Recently ,advances in biochemical,genetic and neuroimaging fields have provided new insights into the thyroid-depression relationship.

       Today,it is well recognized that disturbance in thyroid function may significantly affect mental status including  emotion and cognition.Both excess and insufficient thyroid hormones can cause mood abnormalities including depression that is generally reversible with adequate thyroid treatment.

     On the other hand,depression can be accompanied by subtle thyroid dysfunction .Overt thyroid disease is rare in depression 1 to 4% of patients with affective disorders are found to have overt hypothyroidism while subclinical hypothyroidism accounts 4% to 40% of this disorder.
Neuropsychiatric manifestation of thyroid disorder:In a research study it has been showed that primary thyroid disorder including both hypothyroidism and hyperthyroidism may be accompanied by various neuropsychiatric manifestation ranging from mild depression and anxiety to overt psychosis.It has also been found that anxiety disorders occur in approximately 60% of hyperthyroid patients while depressive disorders occurred in 35% to 69% .On the other hand ,hypothyroid patient's frequently demonstrate features of depression ,cognitive dysfunction ,apathy and psychomotor slowing.
Association of depression with postpartum thyroid disease:The association of postpartum depression with postpartum thyroiditis(inflammation of thyroid gland) or with positive thyroid antibodies is still not well defined.In a study on this,higher frequency to moderate depression was observed in postpartum female subjects with positive antithyroid antibodies regardless of thyroid function .
Neuroimaging of thyroid and mood disorder:A few studies showed changes in cerebral perfusion and metabolism in patients with hypothyroidism particularly those with Hashimoto's thyroiditis  or status post thyroidectomy for thyroid carcinoma.Some have reported diffuse global hypoperfusion  while others demonstrated decrease regional cerebral blood flow.

                   Clinical investigations have long recognized the link between thyroid and depression ,while patient's with hypothyroidism commonly manifest feature of depression and hyperthyroid patient's with wider spectrum of neuropsychiatric symptoms both depression and anxiety .On the other hand ,most of the patient with primary depression have normal thyroid function.  

  So,people who have a thyroid gland that is not functioning properly are more likely to have bipolar disorder,panic disorder,OCD,major depression and wide range of mood disorder than the people in general.If hypo or hyperthyroidism left untreated ,this can lead to many complications including heart problem,nerve injury,infertility and in severe cases death .But besides these health issues the mental condition of a thyroid patient needs to be improved with proper treatment along with love,care and patience.As diseased people usually become mentally weak it can lead to severe catastrophic condition than the disease itself. So, family members and friends of any thyroid patient should try to keep the patient mentally strong,happy and stress free as much as they can.Cause sometime proper treatment is not the only solution of all kind of disease.But it is true that  proper treatment and medication has important role in the health and optimal function of thyroid patient's brain including cognitive function,the ability to concentrate ,mood ,memory ,emotions and ability to cope with life's stress.