In a recently published case study, doctors describe how a woman with treatment-resistant depression was eventually diagnosed with a brain tumor.

“Depressive symptoms may be the only expression of brain tumors,” Dr. Sophie Dautricourt of Centre Hospitalier Universitaire Caen, France, and colleagues write in BMJ Case Reports. “Thus, it is challenging to suspect a brain tumor when patients with depression have a normal neurological examination.”

They illustrate this phenomena by outlining the case of a 54-year-old woman who had been depressed for six months. She was experiencing apathy, difficulties making decisions, sleep disorders, suicidal thoughts, and problems with concentration and attention.

There was no personal or family history of mental illness, but she had recently gone through several stressful events. The antidepressant fluoxetine and the anti-anxiety medication bromazepam had no effect and were discontinued after five months.

Once the patient was given a brain CT scan and MRI scan, it became clear she had several meningiomas, common tumors of the central nervous system, with a giant meningioma in the left frontal lobe. These tumors are not usually cancerous, and affect the membranes that surround the brain and spinal cord. They can lead to erosion and thinning of the skull.

The left frontal lobe “is an area known to have an important role in the development of depression for patients with tumors in the brain,” the experts write.

“Her meningiomatosis improved after surgery,” they add. “The depressive symptoms disappeared within one month. This case highlights the importance of identifying signs of brain tumor in patients with depression.”

The experts write that psychiatric symptoms such as depression, mania, hallucinations, anxiety disorders, and anorexia nervosa, even without any neurological signs, may be a sign of a brain tumor, although “it seems unrealistic to prescribe brain imaging in every patient with a depressive syndrome.”

A study published in May 2016 investigated the rate of significant psychiatric symptoms in patients with meningiomas and found that they affect up to 35 percent of patients. Dr. Kalyan Bommakanti of Nizam’s Institute of Medical Sciences in Hyderabad, India, and colleagues also looked at the factors that influence these psychiatric symptoms, and the effects of surgery.

They recruited 57 meningioma patients aged 15 and 65 years seen in the hospital between 2006 and 2009. Psychiatric symptoms occurred most often in the group with meningiomas in the temporal area (60 percent), followed by the frontal area (46 percent).

Tumors located in the frontal cerebral lobe were associated with more severe depressive symptoms than tumors in the posterior brain region. Overall risk of psychiatric symptoms was much higher for patients with larger meningiomas rather than smaller tumors.

Following surgery, none of the patients developed new psychiatric symptoms. Among those with psychiatric symptoms, 45 percent completely recovered, 40 percent partly recovered, and 15 percent did not improve at all.

In the journal Clinical Neurology and Neurosurgery, they write, “Surgical excision of meningiomas ameliorates the psychiatric symptoms, either completely or partly, in the majority of patients.”

Commenting on her case study, Dautricourt says that the location of the tumor “points to an important role in the development of depression for patients with a brain tumor.” She explains, “Disruption of the frontolimbic connections appears to play a more important role than the frontal cortex lesions themselves, in the development of depressive mood states.”

She states, “Detecting a brain tumor in patients with depression is a primary concern. Indeed, removing a brain tumor can mitigate brain damage, but may also decrease or alleviate depressive symptoms.”

Currently, there is no consensus on when to carry out brain imaging in patients with depressive syndromes.

The team recommends brain imaging in cases with some abnormalities in a neurological examination, or in the absence of neurological signs, when there is late onset of depressive syndrome (after 50 years of age); treatment-resistant depression; or apathy without dysphoric manifestations or with a reduced emotional response.

There is also some debate among experts over the need for brain imaging when the patient has new-onset psychosis, new-onset mood or memory symptoms, new or atypical psychiatric symptoms, and personality changes.

“In conclusion,” they write, “we recommend using brain imaging for tracking these clinical particularities in patients with depression. This approach can lead to an early diagnosis of brain tumors and, thus, improve the functional and vital prognosis of these patients.”