Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  | Brand | Active ingredient | Therapeutic area | Pathology |
| --- | --- | --- | --- | --- |
| 1 | Ebastel and others | Ebastine* | Respiratory | Allergy |
| 2 | Prevencor | Atorvastatin | Cardiovascular | Cholesterol |
| 3 | Esertia | Escitalopram | Central nervous system | Depression |
| 4 | Plusvent | Salmeterol+fluticasone | Respiratory | Asthma & COPD |
| 5 | Almogran and others | Almotriptan* | Central nervous system | Migraine |
| 6 | Parapres | Candesartan cilexetil | Cardiovascular | Hypertension |
| 7 | Airtal and others | Aceclofenac* | Osteomuscular | Pain |
| 8 | Opiren | Lansoprazole | Digestive | Ulcer |
| 9 | Dobupal | Venlafaxine | Central nervous system | Depression |
| 10 | Tesavel & Efficib | Sitagliptin & sitagliptin + metformin | Gastrointestinal | Diabetes |
| 11 | Solaraze | Diclofenac solium + hyaluronic | Dermatology | Actinic keratoses |
| 12 | Almax and others | Almagate* | Gastrointestinal | Antacid |
| 13 | Balneum and others | Soya oil | Dermatology | Atopic dermatitis |
| 14 | Pantopam | Pantoprazole | Gastrointestinal | Gastroesophageal reflux |
| 15 | Decoderm Tri and others | Fluprednidene | Dermatology | Mycotic dermatitis |
Question:
how many brands treat the central nervous system?
Answer:
3