Chemical imbalance hypothesis has been used to explain depression/anxiety and justify the use of anti-depressants to increase serotonin in the brain. This is the same as saying that I have a deficiency of alcohol or sugar in my body because I feel more happier after having alcohol or sweets. This hypothesis is not true.
As noted above, the Mind exists as "neural electrical transmissions" within the brain. I call this the 'software' that requires a healthy hardware (i.e. Brain) to run properly.
In reality, psychological symptoms develop due to a complex interplay between external & internal environment, previous or current stressful events, expectations, beliefs, desires, medical illnesses, nutrition imbalances, toxins, etc.
Anti-depressants increase serotonin in *all* areas of the body (including gut and brain). This triggers not only side effects but the body (including the brain) also starts to down-regulate the number of receptors, thus creating a new balance and also making the medication eventually ineffective. Coming off the medication will now be even harder because the brain does not have the necessary number of receptors to work effectively without medication - i.e. the person becomes drug dependent.
As part of the work up, I will initially perform a thorough assessment of lifestyle, nutrition, medical diagnoses and timeline of important life events and then suggest appropriate management.