Transit NEPTUNE in Aspects to Natal NEPTUNE

Natal Neptune is the sign where your Neptune was placed during birth time, and from there other houses are calculated clock-wise.
If you were born with Neptune in Scorpio, then your natal house is Scorpio (Vrischika Rasi) and during transit, Rahu/Ketu forming conjunction (in Scorpio), sextile (aspect of 60° which are Capricorn and Virgo in this case), square (aspect of 90° which are Aquarius and Leo here), trine (aspect of 120° which are Pisces and Cancer here), opposition (aspect of 180° which is Taurus here) are discussed in this article.
Conjunction is transiting through same sign as in birth chart, sextile is transiting 3rd or 11th house, trine is transiting 5th or 9th house, opposition is transiting 7th house from natal sign.
It takes 165 years for Neptune to come back to its natal position and this transit is of not much importance to humans. But countries, states, big organizations can experience Transit Uranus conjunct Natal Uranus. Humans experience sextile, square, trine and opposition.
Transit NEPTUNE in Aspects to Natal NEPTUNE

Transit Neptune conjunct Natal Neptune : This transit can occur only if Neptune by retrograde motion crosses it’s natal position in early infancy. In such a case either the infant is fascinated by the memories of good happenings of past life or is terrified by the horrible happenings of that life. This is because subconscious mind is more at work during infancy. In less evolved or less civilized races this is attributed to some deity or astral entity as her or his curse.

Transit Neptune Sextile Natal Neptune : This transit characterizes a period of clairvoyance and intuitive guidance. The native is subconsciously motivated at this time. The native emotionally enjoys a happy time with siblings and neighbors. The native is now creative mentally in art, music, psychology, trapping the beauty of nature etc. and by associating himself with educational, religious and social institutions.

Transit Neptune Square Natal Neptune : Disturbance in emotional and domestic sphere characterize this transit. A transit when the native seeks solitude psychologically. The native avoids fulfilling his domestic and professional responsibilities and thinks about unreal situations. Psychic stresses undermine the health and one should refrain from drugs and alcohol. Some associate themselves to strange religious cults for psychological escape. Under severe afflictions to this transit the native may be subject to hallucinations as if he or she is particular deity and may be institutionalized to set it right.

Transit Neptune Trine Natal Neptune : Selfless actions and creative inspirations characterize this transit. The native is intellectually attracted to philosophical, psychological and mystical studies, meditation and spiritual practices. A very good period for creative artists, musicians and literary persons. The native is helpful to the needy and disadvantaged.

Transit Neptune Opposition Natal Neptune : This transit demands thinking on spiritual lines to avoid any confusion. This transit if occurs very late in life when all the life sustaining forces are exhausting and the native has compulsorily to adopt the only way that is to associate himself to spirituality.