**6. Indications**

There are many indications and may be grossly divided into two categories, namely therapeutic and non-therapeutic.

#### **6.1 Therapeutic**

### *6.1.1 Depression*

Major depression is the first FDA approved indication for TMS. Multiple metaanalyses suggest that rTMS has a comparable effect to electroconvulsive therapy and antidepressants. It shows significant improvement in both helpless and anhedonic

symptoms, with squared deviation from mean (SDM) 1.34 and 1.87, respectively [22]. The standard protocol is to deliver 10 Hz stimulation to left dorsolateral prefrontal cortex over 4–6 week in once-daily stimulation session. Other treatment protocols are also available [22]. iTBS is also proven to be as effective as the standard rTMS protocol with response rate of 36.7% when compared with 33.3% in standard rTMS protocol [23].

### *6.1.2 Obsessive and compulsive disorders (OCD)*

OCD is another FDA approved indication for TMS. Multiple meta-analyses suggest rTMS is effective [24]. There are a couple of rTMS protocols with different targets like supplementary motor area, orbitofrontal cortex and dorsolateral prefrontal cortex [25, 26]. cTBS may also show a therapeutic effect in treating OCD at 6 weeks in terms of Yale–Brown Obsessive–Compulsive Scale and Hamilton Anxiety Rating Scale [27].

#### *6.1.3 Smoking cessation*

FDA clearance for TMS on smoking cessation was granted in 2020. It was based on a pivotal randomized controlled trial sponsored by a pharmacological company [28]. It used H coil to stimulate lateral prefrontal cortex and insula by facilitatory rTMS and achieved 28.0% continuous quit rate at week 18 compared to 11.7% in sham group [28]. With this landmark paper, more evidence was concluded from systematic reviews and meta-analyses in proving the effectiveness of rTMS on smoking cessation [29].
