24

Bioinformatics of the Brain

life in 1 of 3 patients with MDD, and residual symptoms of varying degrees

are observed in the period between seizures [178]. MDD can be seen at any

age, but it is more common in the middle ages, especially between the ages

of 40–50. However, in many studies, the mean age of onset was found to be

in the late 20s [180]. The age at which MDD manifests itself is significant

due to its association with worsening social and occupational functioning, a

decline in quality of life, an increase in depressive episodes, and the severity of

symptoms, as well as a rise in suicide attempts and comorbid psychotic and

physical illnesses. The risk of MDD is higher in singles, separated, widowed

and divorced than married people [180, 181].

Changes in neuronal and glial cell density and size have been reported

in many different frontolimbic brain regions such as the prefrontal cortex,

orbitofrontal cortex, anterior cingulate cortex, amygdala, and hippocampus in

depression [182]. Ventricular enlargement has been observed in patients with

depression by CT and MRI studies, but these findings were not considered

specific [183]. It is suggested that SPECT and PET findings obtained from

depression patients can provide information about depression subtypes or can

be used in the differential diagnosis of treatment-resistant and complicated

cases [184].

The analysis of the hereditary component of MDD in individuals has re-

vealed that, in comparison to the general population, there is a greater likeli-

hood of a patient’s first-generation relatives receiving a diagnosis of depression

[185]. Various therapies and medications are used today in the treatment of

depression. Electroconvulsive therapy is a technique utilized to treat depres-

sion. A single type of therapy method will not be sufficient to alleviate the

symptoms of the disorder, as the causes of depression are not observed in

the same way in every individual, and individuals respond differently to the

treatment methods applied [186].

1.8.5

Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is a neurodevelopmental condition that man-

ifests in early childhood. The term “autism” was first used by Swiss psychia-

trist Eugen Bleur in 1911. The term “autistic”, which Bleur defines as “adult

schizophrenia”, comes from the Greek word “otos” and means “self”. Bleur

used this term to describe the negative behavior of individuals who completely

isolate themselves from the outside world and are not interested in what is

happening there [187]. ASD symptoms vary depending on developmental level

and chronological age. A newborn with autism is different from other babies

and is described as a well-behaved baby. He acts as if he does not need his

mother, and is indifferent to her closeness, distance, presence, absence, and

strangers [188]. Children diagnosed with ASD have deficiencies in eye-to-eye

communication, understanding social stimuli, using body language, and fa-

cial expressions. They exhibit problematic behaviors due to these deficiencies

[189]. Delay in speech is often the first symptom that attracts attention in the