When you understand how our chemistry, our diet & our environment influences our conscious self including past experiences you may have forgotten, you'll probably have a better understanding of why things occur. If you look at the Tryptophan pathway, SSRI's can be viewed like some sort of (SQL, XSS, Code) injection attack, influencing your chemistry and your emotions in other ways which may have given you a short term boost, but may not have addressed the underlying cause.
Monotherapy's are simple to use much like A/B testing, but time consuming, a type of resource burn for intelligence gathering, but its the best on offer for most.
Keeping a diary, paying attention to your diet, your life, identifying what you like and dont like, what you want to achieve can help but be mindful your chemistry will influence those thoughts. Think back to when you were a child and the things you wanted then and what you want now, they will be different because your chemistry has changed.
The medical profession recognise how chemistry influences our thoughts because SSRI's exist as have MAOI's as a first generation anti depressant, but their primary application as an anti depressant may not always be the intended purpose as the tryptophan pathway can highlight.
You see this with Gabapentin, nerve pain, could be a symptom of diabetic neuropathy. Only the Germans use alpha-lipoic acid as a medicine for diabetic neuropathy according to some online sources. The only sugar the immune system does not attack is starch. Manganese is also related to diabetes. Likewise too much B6 can cause auto immune diseases as can sodium (Th 17 cells) and highlight weaknesses in your body which need addressing, which could be your nervous system, the myelin sheath (histidine).
You dont say if you are male or female, but histidine is concentrated in the chest of males, religions have identified this as the missionary position for enjoyable exercise, which is why we don't eat Roosters, only feminised meat with the exception of beef in the West unless that's also come from dairy stock. From a meta data point of view, males strutting their chest are exhibiting their histidine levels in plain sight, just like grey hair can exhibit tyrosine deficiency and freckles on a kids face exhibits a healthy tyrosine balance amongst other things.
The body is a complex chemical reaction and whilst science attempts to understand it, its limited in a number of ways and shouldn't be seen as a panacea, when history and religion also has much metadata to offer.
For example diabetes, first documented 600 years bc in Persia (Iran), still not addressed in any meaningful way, a useful stealth weapon operating in plain sight, the sugar in a can of coke can reduce testosterone levels by 25% in teenage males as one example to control known threats in society. Religions also use their teachings to control populations, Ramadan, no food or fluids during daylight hours, lack of fluid increase blood sugar levels, increases the chances of followers developing pre-diabetes or diabetes, ergo males controlled as their intelligence increases.
Every system of control, beit religion, govt have stealth ways to control people and using health is just one of those ways which is why I say keep a diary and have an open mind. No one chemical does one thing in the body.