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 Table of Contents    
Year : 2014  |  Volume : 56  |  Issue : 2  |  Page : 185-187
A rare case of fish odor syndrome presenting as depression

1 Department of Psychiatry, Military Hospital, Danapur, Patna, Bihar, India
2 M. A. Psychology, Research Scholar, Veer Kunwar Singh University, Patna, Bihar, India

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Date of Web Publication11-Apr-2014


A young lady presents to the psychiatry out-patient department with depressive symptoms. Evaluation revealed long standing stressor in the form of a foul odor emanating from her body and over a period of time resulting in social withdrawal and depression with significant impairment of day-to-day functioning. A diagnosis of trimethylaminurea (fish odor syndrome) and adjustment disorder was arrived at. Careful empathetic handling with psychoeducation, behavioral and cognitive counseling and a short course of antidepressants helped her improve significantly with return to almost normal functioning.

Keywords: Depression, fish odor syndrome, trimethylaminuria

How to cite this article:
Khan SA, Shagufta K. A rare case of fish odor syndrome presenting as depression. Indian J Psychiatry 2014;56:185-7

How to cite this URL:
Khan SA, Shagufta K. A rare case of fish odor syndrome presenting as depression. Indian J Psychiatry [serial online] 2014 [cited 2021 Sep 20];56:185-7. Available from:

   Introduction Top

Triemthylaminuria, a rare genetic disorder also known as "fish odor syndrome" is a disorder of amino acid metabolism, caused by the deficiency of enzyme flavin containing monooxygenase (FMO). [1] It is an uncurable condition and is characterized by a foul putrid smell emanating from the body, which can be socially repulsive and personally demoralizing. The presentation may not be direct to a physician, but indirectly as depressive symptoms to a psychiatrist. One such case is described here where a young unmarried girl was brought to medical help by her mother in a suicidal state after prolonged suffering in ignorance. Uninterrupted, her suffering might have naturally progressed to severe dysfunction and possible suicide. Psychiatric intervention mainly by empathetic, supportive, behavioral and cognitive psychotherapy helped her regain confidence and an acceptable level of functionality in socio-academic sphere.

   Case Report Top

This was a case report of a 20-year-old unmarried female patient who reported to psychiatry out-patient department accompanied by her mother. The presenting complaints were irritable mood, not taking interest in household chores, not socializing with friends and colleagues and dropped out of college for last 6 months.

During the course of the interview, a peculiar putrid smell filled the air and on direct questioning in the next interview the mother gave h/o rotten ("intolerable") vegetable smell emanating from her body. Although the odor was present since adolescence it was more noticeable since the last 2-3 years. The smell increased in summers and winters were a shade better. She had increased odor during the menstrual periods and after games/physical exertion, more toward the evening. The intensity was overall waxing and waning in time. In an attempt to avoid criticism and ostracization she had receded in her social interactions. Over the last 6 months she had become irritable, easily moved to tears and anger in the house, lost interest in studies and refused to participate in the household chores. She stopped going to college and had got herself enrolled in a graduate correspondence course.

Personal history revealed uneventful childhood with no h/o abuse/trauma or separation from parental figures. She was good in studies and made a lot of friends, was a stable extrovert. Dietary history revealed non-vegetarian preference, pulses and cereals. She had a special liking for fried dals like moongdaal and daaalmoth (a fried readymade preparation of yellow and black and green lentils, flakes, groundnut and spices). She used to munch on this item throughout the day. Fruit and salad intake was minimal and fish was consumed in the house once or twice a week.

Mother gave h/o similar smell in the father described as "rotten egg like" emanating from her husband and she gave horrid details of the difficult time she had with him after marriage due to this odor ("only I know how I have tolerated him. He being a male could get away with it but she is a girl, who will tolerate her").

There was no past h/o mood abnormality or genetic loading of mental illness or suicide in the family.

Examination revealed increased tendency to sweating. Mental state examination revealed features of depression of moderate intensity and embarrassment with social isolation and disturbed sleep off and on. There were passive suicidal ideas present though no active plans or attempts. There was no psychosis and insight was present.

Beck depression inventory scores were 34/62. Inv - T3, T4, thyroid stimulating hormone, liver function test, urea creatinine, erythrocyte sedimentation rate within normal limits. Urine for R/E and M/E was normal. Urine for the ratio of trimethylamine (TMA) to trimethylamine oxide (TMAO) was positive for trimethylaminurea. Genetic testing was offered for the patient and family members but refused.

She was managed as a case of trimethylaminuria (TMAU) and adjustment disorder (depressive reaction) and managed comprehensively in consultation with the physician.

Treatment was multipronged - dietary, drugs and counseling-cognitive and psychoeducation as well as behavioral and family counseling.

Repeated counseling sessions were held with an aim towards psycho education about the illness and behavioral management to mitigate the effects of the illness - the fact was driven home that this was a rare condition, which varied in severity temporally and across individuals and there have been individuals who have lived with the condition satisfactorily with slight modification in lifestyle (including her own father). Behavioral modifications - daily twice a day bath with use of available adjuncts to avoid body odor such as soap meant for sweaty skin," use of antiperspirant powder and scrubs especially over sweaty areas in social situations, avoiding humid situations/weather, light clothing, use of perfumes and deodorants. Restarting social interactions with core group of friends and relatives while continuing her distance education. Family was counseled to be supportive and not critical even in a lighter vein (vis-a-vis siblings).

Dietary modifications were made to avoid the frequent munching of daals/lentil preparation and eggs. Use of green leafy vegetables encouraged. Drugs were started in the initial phase to tide over the depressive phase- T sertraline 50 mg OD.

Cognitive counseling was offered to negate the depressive cognitions and resultant social withdrawal - individualization/personalization of critical social cues, avoidance of critical self-appraisal all the time, positive self-image, avoidance of catastrophic inference drawn from perceived (and sometimes real) neglect ("there is no place for me in the society," "I am doomed") and activity scheduling. A "no suicide pact" was entered into.

Over a period of 4 weeks, she had recovered significantly in that there was "hardly noticeable" odor in the room when she came for interview, she smiled, looked more "in control," was dressed smartly with a liberal sprinkling of perfume, had started limited social interaction and appeared confident, talked/discussed freely about the illness and was planning to take up a course in web designing and a job (home based web designing) thereafter. At 6 monthly review she was euthymic, confident and has given consent to her family to look for a suitable match for her.

   Discussion Top

TMAU, also known as fish odor syndrome [1] is a rare metabolic disorder with an autosomal recessive pattern of inheritance. This is due to a defect in the normal production of the enzyme FMO 3. [2],[3] as a result of which, the body loses the ability to properly break down TMA from precursor compounds in food digestion into TMAO. TMA then builds up and is released in the person's sweat, urine and breath, giving off a strong fishy odor or strong body odor. The odor is not necessarily fishy and the type of odor can vary from time to time.

This can be a life-disruptive disorder. It adversely affect the livelihood of the people who have it, as well as their families. People, especially children, with the condition may face rejection or a lack of understanding from peers. Some people with TMAU have a strong odor all the time, but most have a moderate smell that varies in intensity over time. Individuals with this condition do not have any physical symptoms and typically appear healthy. [4]

The condition seems to be more common in women than men, for unknown reasons. Symptoms can worsen just before and during menstrual periods, after taking oral contraceptives and around menopause. [4]


Measurement of urine for the ratio of TMA to TMAO is the standard screening test. Genetic testing can be used to identify carriers of this condition.


Currently, there is no known cure for the disorder. However, some people affected by the disorder live relatively normal lives by managing their symptoms and with counseling.

Ways of reducing the fishy odor may include:

  • Avoiding foods such as eggs, legumes, certain meats, fish and other foods that contain choline, carnitine, nitrogen and sulfur
  • Taking low doses of antibiotics such as neomycin and metronidazole [5] in order to reduce the amount of bacteria in the gut
  • Using slightly acidic detergent with a pH between 5.5 and 6.5
  • Studies have described the use of dietary supplements, activated charcoal and copper chlorophyllin with unconfirmed and variable clinical response. [6]

   References Top

1.Mitchell SC, Smith RL. Trimethylaminuria: The fish malodor syndrome. Drug Metab Dispos 2001;29:517-21.  Back to cited text no. 1
2.Treacy EP, Akerman BR, Chow LM, Youil R, Bibeau C, Lin J, et al. Mutations of the flavin-containing monooxygenase gene (FMO3) cause trimethylaminuria, a defect in detoxication. Hum Mol Genet 1998;7:839-45.  Back to cited text no. 2
3.Zschocke J, Kohlmueller D, Quak E, Meissner T, Hoffmann GF, Mayatepek E. Mild trimethylaminuria caused by common variants in FMO3 gene. Lancet 1999;354:834-5.  Back to cited text no. 3
4.Humbert JA, Hammond KB, Hathaway WE. Trimethylaminuria: The fish-odour syndrome. Lancet 1970;2:770-1.  Back to cited text no. 4
5.Treacy E, Johnson D, Pitt JJ, Danks DM. Trimethylaminuria, fish odour syndrome: A new method of detection and response to treatment with metronidazole. J Inherit Metab Dis 1995;18:306-12.  Back to cited text no. 5
6.Yamazaki H, Fujieda M, Togashi M, Saito T, Preti G, Cashman JR, et al. Effects of the dietary supplements, activated charcoal and copper chlorophyllin, on urinary excretion of trimethylamine in Japanese trimethylaminuria patients. Life Sci 2004;74:2739-47.  Back to cited text no. 6

Correspondence Address:
Shahbaz Ali Khan
Department of Psychiatry, Military Hospital, Danapur, Patna, Bihar
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0019-5545.130505

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